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Chapter 7. Network security

7.1. Understanding network policy APIs

Kubernetes offers two features that users can use to enforce network security. One feature that allows users to enforce network policy is the NetworkPolicy API that is designed mainly for application developers and namespace tenants to protect their namespaces by creating namespace-scoped policies.

The second feature is AdminNetworkPolicy which consists of two APIs: the AdminNetworkPolicy (ANP) API and the BaselineAdminNetworkPolicy (BANP) API. ANP and BANP are designed for cluster and network administrators to protect their entire cluster by creating cluster-scoped policies. Cluster administrators can use ANPs to enforce non-overridable policies that take precedence over NetworkPolicy objects. Administrators can use BANP to set up and enforce optional cluster-scoped network policy rules that are overridable by users using NetworkPolicy objects when necessary. When used together, ANP, BANP, and network policy can achieve full multi-tenant isolation that administrators can use to secure their cluster.

OVN-Kubernetes CNI in OpenShift Container Platform implements these network policies using Access Control List (ACL) Tiers to evaluate and apply them. ACLs are evaluated in descending order from Tier 1 to Tier 3.

Tier 1 evaluates AdminNetworkPolicy (ANP) objects. Tier 2 evaluates NetworkPolicy objects. Tier 3 evaluates BaselineAdminNetworkPolicy (BANP) objects.

OVK-Kubernetes Access Control List (ACL)

ANPs are evaluated first. When the match is an ANP allow or deny rule, any existing NetworkPolicy and BaselineAdminNetworkPolicy (BANP) objects in the cluster are skipped from evaluation. When the match is an ANP pass rule, then evaluation moves from tier 1 of the ACL to tier 2 where the NetworkPolicy policy is evaluated. If no NetworkPolicy matches the traffic then evaluation moves from tier 2 ACLs to tier 3 ACLs where BANP is evaluated.

7.1.1. Key differences between AdminNetworkPolicy and NetworkPolicy custom resources

The following table explains key differences between the cluster scoped AdminNetworkPolicy API and the namespace scoped NetworkPolicy API.

Policy elementsAdminNetworkPolicyNetworkPolicy

Applicable user

Cluster administrator or equivalent

Namespace owners

Scope

Cluster

Namespaced

Drop traffic

Supported with an explicit Deny action set as a rule.

Supported via implicit Deny isolation at policy creation time.

Delegate traffic

Supported with an Pass action set as a rule.

Not applicable

Allow traffic

Supported with an explicit Allow action set as a rule.

The default action for all rules is to allow.

Rule precedence within the policy

Depends on the order in which they appear within an ANP. The higher the rule’s position the higher the precedence.

Rules are additive

Policy precedence

Among ANPs the priority field sets the order for evaluation. The lower the priority number higher the policy precedence.

There is no policy ordering between policies.

Feature precedence

Evaluated first via tier 1 ACL and BANP is evaluated last via tier 3 ACL.

Enforced after ANP and before BANP, they are evaluated in tier 2 of the ACL.

Matching pod selection

Can apply different rules across namespaces.

Can apply different rules across pods in single namespace.

Cluster egress traffic

Supported via nodes and networks peers

Supported through ipBlock field along with accepted CIDR syntax.

Cluster ingress traffic

Not supported

Not supported

Fully qualified domain names (FQDN) peer support

Not supported

Not supported

Namespace selectors

Supports advanced selection of Namespaces with the use of namespaces.matchLabels field

Supports label based namespace selection with the use of namespaceSelector field

7.2. Admin network policy

7.2.1. OVN-Kubernetes AdminNetworkPolicy

7.2.1.1. AdminNetworkPolicy

An AdminNetworkPolicy (ANP) is a cluster-scoped custom resource definition (CRD). As a OpenShift Container Platform administrator, you can use ANP to secure your network by creating network policies before creating namespaces. Additionally, you can create network policies on a cluster-scoped level that is non-overridable by NetworkPolicy objects.

The key difference between AdminNetworkPolicy and NetworkPolicy objects are that the former is for administrators and is cluster scoped while the latter is for tenant owners and is namespace scoped.

An ANP allows administrators to specify the following:

  • A priority value that determines the order of its evaluation. The lower the value the higher the precedence.
  • A set of pods that consists of a set of namespaces or namespace on which the policy is applied.
  • A list of ingress rules to be applied for all ingress traffic towards the subject.
  • A list of egress rules to be applied for all egress traffic from the subject.
AdminNetworkPolicy example

Example 7.1. Example YAML file for an ANP

apiVersion: policy.networking.k8s.io/v1alpha1
kind: AdminNetworkPolicy
metadata:
  name: sample-anp-deny-pass-rules 1
spec:
  priority: 50 2
  subject:
    namespaces:
      matchLabels:
          kubernetes.io/metadata.name: example.name 3
  ingress: 4
  - name: "deny-all-ingress-tenant-1" 5
    action: "Deny"
    from:
    - pods:
        namespaceSelector:
          matchLabels:
            custom-anp: tenant-1
        podSelector:
          matchLabels:
            custom-anp: tenant-1 6
  egress:7
  - name: "pass-all-egress-to-tenant-1"
    action: "Pass"
    to:
    - pods:
        namespaceSelector:
          matchLabels:
            custom-anp: tenant-1
        podSelector:
          matchLabels:
            custom-anp: tenant-1
1
Specify a name for your ANP.
2
The spec.priority field supports a maximum of 100 ANP in the values of 0-99 in a cluster. The lower the value the higher the precedence. Creating AdminNetworkPolicy with the same priority creates a nondeterministic outcome.
3
Specify the namespace to apply the ANP resource.
4
ANP have both ingress and egress rules. ANP rules for spec.ingress field accepts values of Pass, Deny, and Allow for the action field.
5
Specify a name for the ingress.name.
6
Specify podSelector.matchLabels to select pods within the namespaces selected by namespaceSelector.matchLabels as ingress peers.
7
ANPs have both ingress and egress rules. ANP rules for spec.egress field accepts values of Pass, Deny, and Allow for the action field.

Additional resources

7.2.1.1.1. AdminNetworkPolicy actions for rules

As an administrator, you can set Allow, Deny, or Pass as the action field for your AdminNetworkPolicy rules. Because OVN-Kubernetes uses a tiered ACLs to evaluate network traffic rules, ANP allow you to set very strong policy rules that can only be changed by an administrator modifying them, deleting the rule, or overriding them by setting a higher priority rule.

AdminNetworkPolicy Allow example

The following ANP that is defined at priority 9 ensures all ingress traffic is allowed from the monitoring namespace towards any tenant (all other namespaces) in the cluster.

Example 7.2. Example YAML file for a strong Allow ANP

apiVersion: policy.networking.k8s.io/v1alpha1
kind: AdminNetworkPolicy
metadata:
  name: allow-monitoring
spec:
  priority: 9
  subject:
    namespaces: {} # Use the empty selector with caution because it also selects OpenShift namespaces as well.
  ingress:
  - name: "allow-ingress-from-monitoring"
    action: "Allow"
    from:
    - namespaces:
        matchLabels:
          kubernetes.io/metadata.name: monitoring
# ...

This is an example of a strong Allow ANP because it is non-overridable by all the parties involved. No tenants can block themselves from being monitored using NetworkPolicy objects and the monitoring tenant also has no say in what it can or cannot monitor.

AdminNetworkPolicy Deny example

The following ANP that is defined at priority 5 ensures all ingress traffic from the monitoring namespace is blocked towards restricted tenants (namespaces that have labels security: restricted).

Example 7.3. Example YAML file for a strong Deny ANP

apiVersion: policy.networking.k8s.io/v1alpha1
kind: AdminNetworkPolicy
metadata:
  name: block-monitoring
spec:
  priority: 5
  subject:
    namespaces:
      matchLabels:
        security: restricted
  ingress:
  - name: "deny-ingress-from-monitoring"
    action: "Deny"
    from:
    - namespaces:
        matchLabels:
          kubernetes.io/metadata.name: monitoring
# ...

This is a strong Deny ANP that is non-overridable by all the parties involved. The restricted tenant owners cannot authorize themselves to allow monitoring traffic, and the infrastructure’s monitoring service cannot scrape anything from these sensitive namespaces.

When combined with the strong Allow example, the block-monitoring ANP has a lower priority value giving it higher precedence, which ensures restricted tenants are never monitored.

AdminNetworkPolicy Pass example

TThe following ANP that is defined at priority 7 ensures all ingress traffic from the monitoring namespace towards internal infrastructure tenants (namespaces that have labels security: internal) are passed on to tier 2 of the ACLs and evaluated by the namespaces’ NetworkPolicy objects.

Example 7.4. Example YAML file for a strong Pass ANP

apiVersion: policy.networking.k8s.io/v1alpha1
kind: AdminNetworkPolicy
metadata:
  name: pass-monitoring
spec:
  priority: 7
  subject:
    namespaces:
      matchLabels:
        security: internal
  ingress:
  - name: "pass-ingress-from-monitoring"
    action: "Pass"
    from:
    - namespaces:
        matchLabels:
          kubernetes.io/metadata.name: monitoring
# ...

This example is a strong Pass action ANP because it delegates the decision to NetworkPolicy objects defined by tenant owners. This pass-monitoring ANP allows all tenant owners grouped at security level internal to choose if their metrics should be scraped by the infrastructures' monitoring service using namespace scoped NetworkPolicy objects.

7.2.2. OVN-Kubernetes BaselineAdminNetworkPolicy

7.2.2.1. BaselineAdminNetworkPolicy

BaselineAdminNetworkPolicy (BANP) is a cluster-scoped custom resource definition (CRD). As a OpenShift Container Platform administrator, you can use BANP to setup and enforce optional baseline network policy rules that are overridable by users using NetworkPolicy objects if need be. Rule actions for BANP are allow or deny.

The BaselineAdminNetworkPolicy resource is a cluster singleton object that can be used as a guardrail policy incase a passed traffic policy does not match any NetworkPolicy objects in the cluster. A BANP can also be used as a default security model that provides guardrails that intra-cluster traffic is blocked by default and a user will need to use NetworkPolicy objects to allow known traffic. You must use default as the name when creating a BANP resource.

A BANP allows administrators to specify:

  • A subject that consists of a set of namespaces or namespace.
  • A list of ingress rules to be applied for all ingress traffic towards the subject.
  • A list of egress rules to be applied for all egress traffic from the subject.
BaselineAdminNetworkPolicy example

Example 7.5. Example YAML file for BANP

apiVersion: policy.networking.k8s.io/v1alpha1
kind: BaselineAdminNetworkPolicy
metadata:
  name: default 1
spec:
  subject:
    namespaces:
      matchLabels:
          kubernetes.io/metadata.name: example.name 2
  ingress: 3
  - name: "deny-all-ingress-from-tenant-1" 4
    action: "Deny"
    from:
    - pods:
        namespaceSelector:
          matchLabels:
            custom-banp: tenant-1 5
        podSelector:
          matchLabels:
            custom-banp: tenant-1 6
  egress:
  - name: "allow-all-egress-to-tenant-1"
    action: "Allow"
    to:
    - pods:
        namespaceSelector:
          matchLabels:
            custom-banp: tenant-1
        podSelector:
          matchLabels:
            custom-banp: tenant-1
1
The policy name must be default because BANP is a singleton object.
2
Specify the namespace to apply the ANP to.
3
BANP have both ingress and egress rules. BANP rules for spec.ingress and spec.egress fields accepts values of Deny and Allow for the action field.
4
Specify a name for the ingress.name
5
Specify the namespaces to select the pods from to apply the BANP resource.
6
Specify podSelector.matchLabels name of the pods to apply the BANP resource.
BaselineAdminNetworkPolicy Deny example

The following BANP singleton ensures that the administrator has set up a default deny policy for all ingress monitoring traffic coming into the tenants at internal security level. When combined with the "AdminNetworkPolicy Pass example", this deny policy acts as a guardrail policy for all ingress traffic that is passed by the ANP pass-monitoring policy.

Example 7.6. Example YAML file for a guardrail Deny rule

apiVersion: policy.networking.k8s.io/v1alpha1
kind: BaselineAdminNetworkPolicy
metadata:
  name: default
spec:
  subject:
    namespaces:
      matchLabels:
        security: internal
  ingress:
  - name: "deny-ingress-from-monitoring"
    action: "Deny"
    from:
    - namespaces:
        matchLabels:
          kubernetes.io/metadata.name: monitoring
# ...

You can use an AdminNetworkPolicy resource with a Pass value for the action field in conjunction with the BaselineAdminNetworkPolicy resource to create a multi-tenant policy. This multi-tenant policy allows one tenant to collect monitoring data on their application while simultaneously not collecting data from a second tenant.

As an administrator, if you apply both the "AdminNetworkPolicy Pass action example" and the "BaselineAdminNetwork Policy Deny example", tenants are then left with the ability to choose to create a NetworkPolicy resource that will be evaluated before the BANP.

For example, Tenant 1 can set up the following NetworkPolicy resource to monitor ingress traffic:

Example 7.7. Example NetworkPolicy

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-monitoring
  namespace: tenant 1
spec:
  podSelector:
  policyTypes:
    - Ingress
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
          kubernetes.io/metadata.name: monitoring
# ...

In this scenario, Tenant 1’s policy would be evaluated after the "AdminNetworkPolicy Pass action example" and before the "BaselineAdminNetwork Policy Deny example", which denies all ingress monitoring traffic coming into tenants with security level internal. With Tenant 1’s NetworkPolicy object in place, they will be able to collect data on their application. Tenant 2, however, who does not have any NetworkPolicy objects in place, will not be able to collect data. As an administrator, you have not by default monitored internal tenants, but instead, you created a BANP that allows tenants to use NetworkPolicy objects to override the default behavior of your BANP.

7.2.3. Monitoring ANP and BANP

AdminNetworkPolicy and BaselineAdminNetworkPolicy resources have metrics that can be used for monitoring and managing your policies. See the following table for more details on the metrics.

7.2.3.1. Metrics for AdminNetworkPolicy

NameDescriptionExplanation

ovnkube_controller_admin_network_policies

Not applicable

The total number of AdminNetworkPolicy resources in the cluster.

ovnkube_controller_baseline_admin_network_policies

Not applicable

The total number of BaselineAdminNetworkPolicy resources in the cluster. The value should be 0 or 1.

ovnkube_controller_admin_network_policies_rules

  • direction: specifies either Ingress or Egress.
  • action: specifies either Pass, Allow, or Deny.

The total number of rules across all ANP policies in the cluster grouped by direction and action.

ovnkube_controller_baseline_admin_network_policies_rules

  • direction: specifies either Ingress or Egress.
  • action: specifies either Allow or Deny.

The total number of rules across all BANP policies in the cluster grouped by direction and action.

ovnkube_controller_admin_network_policies_db_objects

table_name: specifies either ACL or Address_Set

The total number of OVN Northbound database (nbdb) objects that are created by all the ANP in the cluster grouped by the table_name.

ovnkube_controller_baseline_admin_network_policies_db_objects

table_name: specifies either ACL or Address_Set

The total number of OVN Northbound database (nbdb) objects that are created by all the BANP in the cluster grouped by the table_name.

7.2.4. Egress nodes and networks peer for AdminNetworkPolicy

This section explains nodes and networks peers. Administrators can use the examples in this section to design AdminNetworkPolicy and BaselineAdminNetworkPolicy to control northbound traffic in their cluster.

7.2.4.1. Northbound traffic controls for AdminNetworkPolicy and BaselineAdminNetworkPolicy

In addition to supporting east-west traffic controls, ANP and BANP also allow administrators to control their northbound traffic leaving the cluster or traffic leaving the node to other nodes in the cluster. End-users can do the following:

  • Implement egress traffic control towards cluster nodes using nodes egress peer
  • Implement egress traffic control towards Kubernetes API servers using nodes or networks egress peers
  • Implement egress traffic control towards external destinations outside the cluster using networks peer
Note

For ANP and BANP, nodes and networks peers can be specified for egress rules only.

7.2.4.1.1. Using nodes peer to control egress traffic to cluster nodes

Using the nodes peer administrators can control egress traffic from pods to nodes in the cluster. A benefit of this is that you do not have to change the policy when nodes are added to or deleted from the cluster.

The following example allows egress traffic to the Kubernetes API server on port 6443 by any of the namespaces with a restricted, confidential, or internal level of security using the node selector peer. It also denies traffic to all worker nodes in your cluster from any of the namespaces with a restricted, confidential, or internal level of security.

Example 7.8. Example of ANP Allow egress using nodes peer

apiVersion: policy.networking.k8s.io/v1alpha1
kind: AdminNetworkPolicy
metadata:
  name: egress-security-allow
spec:
  egress:
  - action: Deny
    to:
    - nodes:
        matchExpressions:
        - key: node-role.kubernetes.io/worker
          operator: Exists
  - action: Allow
    name: allow-to-kubernetes-api-server-and-engr-dept-pods
    ports:
    - portNumber:
        port: 6443
        protocol: TCP
    to:
    - nodes: 1
        matchExpressions:
        - key: node-role.kubernetes.io/control-plane
          operator: Exists
    - pods: 2
        namespaceSelector:
          matchLabels:
            dept: engr
        podSelector: {}
  priority: 55
  subject: 3
    namespaces:
      matchExpressions:
      - key: security 4
        operator: In
        values:
        - restricted
        - confidential
        - internal
1
Specifies a node or set of nodes in the cluster using the matchExpressions field.
2
Specifies all the pods labeled with dept: engr.
3
Specifies the subject of the ANP which includes any namespaces that match the labels used by the network policy. The example matches any of the namespaces with restricted, confidential, or internal level of security.
4
Specifies key/value pairs for matchExpressions field.
7.2.4.1.2. Using networks peer to control egress traffic towards external destinations

Cluster administrators can use CIDR ranges in networks peer and apply a policy to control egress traffic leaving from pods and going to a destination configured at the IP address that is within the CIDR range specified with networks field.

The following example uses networks peer and combines ANP and BANP policies to restrict egress traffic.

Important

Use the empty selector ({}) in the namespace field for ANP and BANP with caution. When using an empty selector, it also selects OpenShift namespaces.

If you use values of 0.0.0.0/0 in a ANP or BANP Deny rule, you must set a higher priority ANP Allow rule to necessary destinations before setting the Deny to 0.0.0.0/0.

Example 7.9. Example of ANP and BANP using networks peers

apiVersion: policy.networking.k8s.io/v1alpha1
kind: AdminNetworkPolicy
metadata:
  name: network-as-egress-peer
spec:
  priority: 70
  subject:
    namespaces: {} # Use the empty selector with caution because it also selects OpenShift namespaces as well.
  egress:
  - name: "deny-egress-to-external-dns-servers"
    action: "Deny"
    to:
    - networks:1
      - 8.8.8.8/32
      - 8.8.4.4/32
      - 208.67.222.222/32
    ports:
      - portNumber:
          protocol: UDP
          port: 53
  - name: "allow-all-egress-to-intranet"
    action: "Allow"
    to:
    - networks: 2
      - 89.246.180.0/22
      - 60.45.72.0/22
  - name: "allow-all-intra-cluster-traffic"
    action: "Allow"
    to:
    - namespaces: {} # Use the empty selector with caution because it also selects OpenShift namespaces as well.
  - name: "pass-all-egress-to-internet"
    action: "Pass"
    to:
    - networks:
      - 0.0.0.0/0 3
---
apiVersion: policy.networking.k8s.io/v1alpha1
kind: BaselineAdminNetworkPolicy
metadata:
  name: default
spec:
  subject:
    namespaces: {} # Use the empty selector with caution because it also selects OpenShift namespaces as well.
  egress:
  - name: "deny-all-egress-to-internet"
    action: "Deny"
    to:
    - networks:
      - 0.0.0.0/0 4
---
1
Use networks to specify a range of CIDR networks outside of the cluster.
2
Specifies the CIDR ranges for the intra-cluster traffic from your resources.
3 4
Specifies a Deny egress to everything by setting networks values to 0.0.0.0/0. Make sure you have a higher priority Allow rule to necessary destinations before setting a Deny to 0.0.0.0/0 because this will deny all traffic including to Kubernetes API and DNS servers.

Collectively the network-as-egress-peer ANP and default BANP using networks peers enforces the following egress policy:

  • All pods cannot talk to external DNS servers at the listed IP addresses.
  • All pods can talk to rest of the company’s intranet.
  • All pods can talk to other pods, nodes, and services.
  • All pods cannot talk to the internet. Combining the last ANP Pass rule and the strong BANP Deny rule a guardrail policy is created that secures traffic in the cluster.
7.2.4.1.3. Using nodes peer and networks peer together

Cluster administrators can combine nodes and networks peer in your ANP and BANP policies.

Example 7.10. Example of nodes and networks peer

apiVersion: policy.networking.k8s.io/v1alpha1
kind: AdminNetworkPolicy
metadata:
  name: egress-peer-1 1
spec:
  egress: 2
  - action: "Allow"
    name: "allow-egress"
    to:
    - nodes:
        matchExpressions:
        - key: worker-group
          operator: In
          values:
          - workloads # Egress traffic from nodes with label worker-group: workloads is allowed.
    - networks:
      - 104.154.164.170/32
    - pods:
        namespaceSelector:
          matchLabels:
            apps: external-apps
        podSelector:
          matchLabels:
            app: web # This rule in the policy allows the traffic directed to pods labeled apps: web in projects with apps: external-apps to leave the cluster.
  - action: "Deny"
    name: "deny-egress"
    to:
    - nodes:
        matchExpressions:
        - key: worker-group
          operator: In
          values:
          - infra # Egress traffic from nodes with label worker-group: infra is denied.
    - networks:
      - 104.154.164.160/32 # Egress traffic to this IP address from cluster is denied.
    - pods:
        namespaceSelector:
          matchLabels:
            apps: internal-apps
        podSelector: {}
  - action: "Pass"
    name: "pass-egress"
    to:
    - nodes:
        matchExpressions:
        - key: node-role.kubernetes.io/worker
          operator: Exists # All other egress traffic is passed to NetworkPolicy or BANP for evaluation.
  priority: 30 3
  subject: 4
    namespaces:
      matchLabels:
        apps: all-apps
1
Specifies the name of the policy.
2
For nodes and networks peers, you can only use northbound traffic controls in ANP as egress.
3
Specifies the priority of the ANP, determining the order in which they should be evaluated. Lower priority rules have higher precedence. ANP accepts values of 0-99 with 0 being the highest priority and 99 being the lowest.
4
Specifies the set of pods in the cluster on which the rules of the policy are to be applied. In the example, any pods with the apps: all-apps label across all namespaces are the subject of the policy.

7.2.5. Troubleshooting AdminNetworkPolicy

7.2.5.1. Checking creation of ANP

To check that your AdminNetworkPolicy (ANP) and BaselineAdminNetworkPolicy (BANP) are created correctly, check the status outputs of the following commands: oc describe anp or oc describe banp.

A good status indicates OVN DB plumbing was successful and the SetupSucceeded.

Example 7.11. Example ANP with a good status

...
Conditions:
Last Transition Time:  2024-06-08T20:29:00Z
Message:               Setting up OVN DB plumbing was successful
Reason:                SetupSucceeded
Status:                True
Type:                  Ready-In-Zone-ovn-control-plane Last Transition Time:  2024-06-08T20:29:00Z
Message:               Setting up OVN DB plumbing was successful
Reason:                SetupSucceeded
Status:                True
Type:                  Ready-In-Zone-ovn-worker
Last Transition Time:  2024-06-08T20:29:00Z
Message:               Setting up OVN DB plumbing was successful
Reason:                SetupSucceeded
Status:                True
Type:                  Ready-In-Zone-ovn-worker2
...

If plumbing is unsuccessful, an error is reported from the respective zone controller.

Example 7.12. Example of an ANP with a bad status and error message

...
Status:
  Conditions:
    Last Transition Time:  2024-06-25T12:47:44Z
    Message:               error attempting to add ANP cluster-control with priority 600 because, OVNK only supports priority ranges 0-99
    Reason:                SetupFailed
    Status:                False
    Type:                  Ready-In-Zone-example-worker-1.example.example-org.net
    Last Transition Time:  2024-06-25T12:47:45Z
    Message:               error attempting to add ANP cluster-control with priority 600 because, OVNK only supports priority ranges 0-99
    Reason:                SetupFailed
    Status:                False
    Type:                  Ready-In-Zone-example-worker-0.example.example-org.net
    Last Transition Time:  2024-06-25T12:47:44Z
    Message:               error attempting to add ANP cluster-control with priority 600 because, OVNK only supports priority ranges 0-99
    Reason:                SetupFailed
    Status:                False
    Type:                  Ready-In-Zone-example-ctlplane-1.example.example-org.net
    Last Transition Time:  2024-06-25T12:47:44Z
    Message:               error attempting to add ANP cluster-control with priority 600 because, OVNK only supports priority ranges 0-99
    Reason:                SetupFailed
    Status:                False
    Type:                  Ready-In-Zone-example-ctlplane-2.example.example-org.net
    Last Transition Time:  2024-06-25T12:47:44Z
    Message:               error attempting to add ANP cluster-control with priority 600 because, OVNK only supports priority ranges 0-99
    Reason:                SetupFailed
    Status:                False
    Type:                  Ready-In-Zone-example-ctlplane-0.example.example-org.net
    ```

See the following section for nbctl commands to help troubleshoot unsuccessful policies.

7.2.5.1.1. Using nbctl commands for ANP and BANP

To troubleshoot an unsuccessful setup, start by looking at OVN Northbound database (nbdb) objects including ACL, AdressSet, and Port_Group. To view the nbdb, you need to be inside the pod on that node to view the objects in that node’s database.

Prerequisites

  • Access to the cluster as a user with the cluster-admin role.
  • The OpenShift CLI (oc) installed.
Note

To run ovn nbctl commands in a cluster, you must open a remote shell into the `nbdb`on the relevant node.

The following policy was used to generate outputs.

Example 7.13. AdminNetworkPolicy used to generate outputs

apiVersion: policy.networking.k8s.io/v1alpha1
kind: AdminNetworkPolicy
metadata:
  name: cluster-control
spec:
  priority: 34
  subject:
    namespaces:
      matchLabels:
        anp: cluster-control-anp # Only namespaces with this label have this ANP
  ingress:
  - name: "allow-from-ingress-router" # rule0
    action: "Allow"
    from:
    - namespaces:
        matchLabels:
          policy-group.network.openshift.io/ingress: ""
  - name: "allow-from-monitoring" # rule1
    action: "Allow"
    from:
    - namespaces:
        matchLabels:
          kubernetes.io/metadata.name: openshift-monitoring
    ports:
    - portNumber:
        protocol: TCP
        port: 7564
    - namedPort: "scrape"
  - name: "allow-from-open-tenants" # rule2
    action: "Allow"
    from:
    - namespaces: # open tenants
        matchLabels:
          tenant: open
  - name: "pass-from-restricted-tenants" # rule3
    action: "Pass"
    from:
    - namespaces: # restricted tenants
        matchLabels:
          tenant: restricted
  - name: "default-deny" # rule4
    action: "Deny"
    from:
    - namespaces: {} # Use the empty selector with caution because it also selects OpenShift namespaces as well.
  egress:
  - name: "allow-to-dns" # rule0
    action: "Allow"
    to:
    - pods:
        namespaceSelector:
          matchlabels:
            kubernetes.io/metadata.name: openshift-dns
        podSelector:
          matchlabels:
            app: dns
    ports:
    - portNumber:
        protocol: UDP
        port: 5353
  - name: "allow-to-kapi-server" # rule1
    action: "Allow"
    to:
    - nodes:
        matchExpressions:
        - key: node-role.kubernetes.io/control-plane
          operator: Exists
    ports:
    - portNumber:
        protocol: TCP
        port: 6443
  - name: "allow-to-splunk" # rule2
    action: "Allow"
    to:
    - namespaces:
        matchlabels:
          tenant: splunk
    ports:
    - portNumber:
        protocol: TCP
        port: 8991
    - portNumber:
        protocol: TCP
        port: 8992
  - name: "allow-to-open-tenants-and-intranet-and-worker-nodes" # rule3
    action: "Allow"
    to:
    - nodes: # worker-nodes
        matchExpressions:
        - key: node-role.kubernetes.io/worker
          operator: Exists
    - networks: # intranet
      - 172.29.0.0/30
      - 10.0.54.0/19
      - 10.0.56.38/32
      - 10.0.69.0/24
    - namespaces: # open tenants
        matchLabels:
          tenant: open
  - name: "pass-to-restricted-tenants" # rule4
    action: "Pass"
    to:
    - namespaces: # restricted tenants
        matchLabels:
          tenant: restricted
  - name: "default-deny"
    action: "Deny"
    to:
    - networks:
      - 0.0.0.0/0

Procedure

  1. List pods with node information by running the following command: 

    $ oc get pods -n openshift-ovn-kubernetes -owide

    Example output

    NAME                                     READY   STATUS    RESTARTS   AGE   IP           NODE                                       NOMINATED NODE   READINESS GATES
ovnkube-control-plane-5c95487779-8k9fd   2/2     Running   0          34m   10.0.0.5     ci-ln-0tv5gg2-72292-6sjw5-master-0         <none>           <none>
ovnkube-control-plane-5c95487779-v2xn8   2/2     Running   0          34m   10.0.0.3     ci-ln-0tv5gg2-72292-6sjw5-master-1         <none>           <none>
ovnkube-node-524dt                       8/8     Running   0          33m   10.0.0.4     ci-ln-0tv5gg2-72292-6sjw5-master-2         <none>           <none>
ovnkube-node-gbwr9                       8/8     Running   0          24m   10.0.128.4   ci-ln-0tv5gg2-72292-6sjw5-worker-c-s9gqt   <none>           <none>
ovnkube-node-h4fpx                       8/8     Running   0          33m   10.0.0.5     ci-ln-0tv5gg2-72292-6sjw5-master-0         <none>           <none>
ovnkube-node-j4hzw                       8/8     Running   0          24m   10.0.128.2   ci-ln-0tv5gg2-72292-6sjw5-worker-a-hzbh5   <none>           <none>
ovnkube-node-wdhgv                       8/8     Running   0          33m   10.0.0.3     ci-ln-0tv5gg2-72292-6sjw5-master-1         <none>           <none>
ovnkube-node-wfncn                       8/8     Running   0          24m   10.0.128.3   ci-ln-0tv5gg2-72292-6sjw5-worker-b-5bb7f   <none>           <none>

  2. Navigate into a pod to look at the northbound database by running the following command: 

    $ oc rsh -c nbdb -n openshift-ovn-kubernetes ovnkube-node-524dt

  3. Run the following command to look at the ACLs nbdb: 

    $ ovn-nbctl find ACL 'external_ids{>=}{"k8s.ovn.org/owner-type"=AdminNetworkPolicy,"k8s.ovn.org/name"=cluster-control}'
    Where, cluster-control
    Specifies the name of the AdminNetworkPolicy you are troubleshooting.
    AdminNetworkPolicy
    Specifies the type: AdminNetworkPolicy or BaselineAdminNetworkPolicy.

    Example 7.14. Example output for ACLs

    _uuid               : 0d5e4722-b608-4bb1-b625-23c323cc9926
action              : allow-related
direction           : to-lport
external_ids        : {direction=Ingress, gress-index="2", "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Ingress:2:None", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy, port-policy-protocol=None}
label               : 0
log                 : false
match               : "outport == @a14645450421485494999 && ((ip4.src == $a13730899355151937870))"
meter               : acl-logging
name                : "ANP:cluster-control:Ingress:2"
options             : {}
priority            : 26598
severity            : []
tier                : 1

_uuid               : b7be6472-df67-439c-8c9c-f55929f0a6e0
action              : drop
direction           : from-lport
external_ids        : {direction=Egress, gress-index="5", "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Egress:5:None", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy, port-policy-protocol=None}
label               : 0
log                 : false
match               : "inport == @a14645450421485494999 && ((ip4.dst == $a11452480169090787059))"
meter               : acl-logging
name                : "ANP:cluster-control:Egress:5"
options             : {apply-after-lb="true"}
priority            : 26595
severity            : []
tier                : 1

_uuid               : 5a6e5bb4-36eb-4209-b8bc-c611983d4624
action              : pass
direction           : to-lport
external_ids        : {direction=Ingress, gress-index="3", "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Ingress:3:None", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy, port-policy-protocol=None}
label               : 0
log                 : false
match               : "outport == @a14645450421485494999 && ((ip4.src == $a764182844364804195))"
meter               : acl-logging
name                : "ANP:cluster-control:Ingress:3"
options             : {}
priority            : 26597
severity            : []
tier                : 1

_uuid               : 04f20275-c410-405c-a923-0e677f767889
action              : pass
direction           : from-lport
external_ids        : {direction=Egress, gress-index="4", "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Egress:4:None", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy, port-policy-protocol=None}
label               : 0
log                 : false
match               : "inport == @a14645450421485494999 && ((ip4.dst == $a5972452606168369118))"
meter               : acl-logging
name                : "ANP:cluster-control:Egress:4"
options             : {apply-after-lb="true"}
priority            : 26596
severity            : []
tier                : 1

_uuid               : 4b5d836a-e0a3-4088-825e-f9f0ca58e538
action              : drop
direction           : to-lport
external_ids        : {direction=Ingress, gress-index="4", "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Ingress:4:None", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy, port-policy-protocol=None}
label               : 0
log                 : false
match               : "outport == @a14645450421485494999 && ((ip4.src == $a13814616246365836720))"
meter               : acl-logging
name                : "ANP:cluster-control:Ingress:4"
options             : {}
priority            : 26596
severity            : []
tier                : 1

_uuid               : 5d09957d-d2cc-4f5a-9ddd-b97d9d772023
action              : allow-related
direction           : from-lport
external_ids        : {direction=Egress, gress-index="2", "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Egress:2:tcp", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy, port-policy-protocol=tcp}
label               : 0
log                 : false
match               : "inport == @a14645450421485494999 && ((ip4.dst == $a18396736153283155648)) && tcp && tcp.dst=={8991,8992}"
meter               : acl-logging
name                : "ANP:cluster-control:Egress:2"
options             : {apply-after-lb="true"}
priority            : 26598
severity            : []
tier                : 1

_uuid               : 1a68a5ed-e7f9-47d0-b55c-89184d97e81a
action              : allow-related
direction           : from-lport
external_ids        : {direction=Egress, gress-index="1", "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Egress:1:tcp", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy, port-policy-protocol=tcp}
label               : 0
log                 : false
match               : "inport == @a14645450421485494999 && ((ip4.dst == $a10706246167277696183)) && tcp && tcp.dst==6443"
meter               : acl-logging
name                : "ANP:cluster-control:Egress:1"
options             : {apply-after-lb="true"}
priority            : 26599
severity            : []
tier                : 1

_uuid               : aa1a224d-7960-4952-bdfb-35246bafbac8
action              : allow-related
direction           : to-lport
external_ids        : {direction=Ingress, gress-index="1", "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Ingress:1:tcp", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy, port-policy-protocol=tcp}
label               : 0
log                 : false
match               : "outport == @a14645450421485494999 && ((ip4.src == $a6786643370959569281)) && tcp && tcp.dst==7564"
meter               : acl-logging
name                : "ANP:cluster-control:Ingress:1"
options             : {}
priority            : 26599
severity            : []
tier                : 1

_uuid               : 1a27d30e-3f96-4915-8ddd-ade7f22c117b
action              : allow-related
direction           : from-lport
external_ids        : {direction=Egress, gress-index="3", "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Egress:3:None", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy, port-policy-protocol=None}
label               : 0
log                 : false
match               : "inport == @a14645450421485494999 && ((ip4.dst == $a10622494091691694581))"
meter               : acl-logging
name                : "ANP:cluster-control:Egress:3"
options             : {apply-after-lb="true"}
priority            : 26597
severity            : []
tier                : 1

_uuid               : b23a087f-08f8-4225-8c27-4a9a9ee0c407
action              : allow-related
direction           : from-lport
external_ids        : {direction=Egress, gress-index="0", "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Egress:0:udp", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy, port-policy-protocol=udp}
label               : 0
log                 : false
match               : "inport == @a14645450421485494999 && ((ip4.dst == $a13517855690389298082)) && udp && udp.dst==5353"
meter               : acl-logging
name                : "ANP:cluster-control:Egress:0"
options             : {apply-after-lb="true"}
priority            : 26600
severity            : []
tier                : 1

_uuid               : d14ed5cf-2e06-496e-8cae-6b76d5dd5ccd
action              : allow-related
direction           : to-lport
external_ids        : {direction=Ingress, gress-index="0", "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Ingress:0:None", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy, port-policy-protocol=None}
label               : 0
log                 : false
match               : "outport == @a14645450421485494999 && ((ip4.src == $a14545668191619617708))"
meter               : acl-logging
name                : "ANP:cluster-control:Ingress:0"
options             : {}
priority            : 26600
severity            : []
tier                : 1
    Note

    The outputs for ingress and egress show you the logic of the policy in the ACL. For example, every time a packet matches the provided match the action is taken.

    1. Examine the specific ACL for the rule by running the following command: 

      $ ovn-nbctl find ACL 'external_ids{>=}{"k8s.ovn.org/owner-type"=AdminNetworkPolicy,direction=Ingress,"k8s.ovn.org/name"=cluster-control,gress-index="1"}'
      Where, cluster-control
      Specifies the name of your ANP.
      Ingress
      Specifies the direction of traffic either of type Ingress or Egress.
      1
      Specifies the rule you want to look at.

      For the example ANP named cluster-control at priority 34, the following is an example output for Ingress rule 1:

      Example 7.15. Example output

      _uuid               : aa1a224d-7960-4952-bdfb-35246bafbac8
action              : allow-related
direction           : to-lport
external_ids        : {direction=Ingress, gress-index="1", "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Ingress:1:tcp", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy, port-policy-protocol=tcp}
label               : 0
log                 : false
match               : "outport == @a14645450421485494999 && ((ip4.src == $a6786643370959569281)) && tcp && tcp.dst==7564"
meter               : acl-logging
name                : "ANP:cluster-control:Ingress:1"
options             : {}
priority            : 26599
severity            : []
tier                : 1

  4. Run the following command to look at address sets in the nbdb: 

    $ ovn-nbctl find Address_Set 'external_ids{>=}{"k8s.ovn.org/owner-type"=AdminNetworkPolicy,"k8s.ovn.org/name"=cluster-control}'

    Example 7.16. Example outputs for Address_Set

    _uuid               : 56e89601-5552-4238-9fc3-8833f5494869
addresses           : ["192.168.194.135", "192.168.194.152", "192.168.194.193", "192.168.194.254"]
external_ids        : {direction=Egress, gress-index="1", ip-family=v4, "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Egress:1:v4", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy}
name                : a10706246167277696183

_uuid               : 7df9330d-380b-4bdb-8acd-4eddeda2419c
addresses           : ["10.132.0.10", "10.132.0.11", "10.132.0.12", "10.132.0.13", "10.132.0.14", "10.132.0.15", "10.132.0.16", "10.132.0.17", "10.132.0.5", "10.132.0.7", "10.132.0.71", "10.132.0.75", "10.132.0.8", "10.132.0.81", "10.132.0.9", "10.132.2.10", "10.132.2.11", "10.132.2.12", "10.132.2.14", "10.132.2.15", "10.132.2.3", "10.132.2.4", "10.132.2.5", "10.132.2.6", "10.132.2.7", "10.132.2.8", "10.132.2.9", "10.132.3.64", "10.132.3.65", "10.132.3.72", "10.132.3.73", "10.132.3.76", "10.133.0.10", "10.133.0.11", "10.133.0.12", "10.133.0.13", "10.133.0.14", "10.133.0.15", "10.133.0.16", "10.133.0.17", "10.133.0.18", "10.133.0.19", "10.133.0.20", "10.133.0.21", "10.133.0.22", "10.133.0.23", "10.133.0.24", "10.133.0.25", "10.133.0.26", "10.133.0.27", "10.133.0.28", "10.133.0.29", "10.133.0.30", "10.133.0.31", "10.133.0.32", "10.133.0.33", "10.133.0.34", "10.133.0.35", "10.133.0.36", "10.133.0.37", "10.133.0.38", "10.133.0.39", "10.133.0.40", "10.133.0.41", "10.133.0.42", "10.133.0.44", "10.133.0.45", "10.133.0.46", "10.133.0.47", "10.133.0.48", "10.133.0.5", "10.133.0.6", "10.133.0.7", "10.133.0.8", "10.133.0.9", "10.134.0.10", "10.134.0.11", "10.134.0.12", "10.134.0.13", "10.134.0.14", "10.134.0.15", "10.134.0.16", "10.134.0.17", "10.134.0.18", "10.134.0.19", "10.134.0.20", "10.134.0.21", "10.134.0.22", "10.134.0.23", "10.134.0.24", "10.134.0.25", "10.134.0.26", "10.134.0.27", "10.134.0.28", "10.134.0.30", "10.134.0.31", "10.134.0.32", "10.134.0.33", "10.134.0.34", "10.134.0.35", "10.134.0.36", "10.134.0.37", "10.134.0.38", "10.134.0.4", "10.134.0.42", "10.134.0.9", "10.135.0.10", "10.135.0.11", "10.135.0.12", "10.135.0.13", "10.135.0.14", "10.135.0.15", "10.135.0.16", "10.135.0.17", "10.135.0.18", "10.135.0.19", "10.135.0.23", "10.135.0.24", "10.135.0.26", "10.135.0.27", "10.135.0.29", "10.135.0.3", "10.135.0.4", "10.135.0.40", "10.135.0.41", "10.135.0.42", "10.135.0.43", "10.135.0.44", "10.135.0.5", "10.135.0.6", "10.135.0.7", "10.135.0.8", "10.135.0.9"]
external_ids        : {direction=Ingress, gress-index="4", ip-family=v4, "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Ingress:4:v4", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy}
name                : a13814616246365836720

_uuid               : 84d76f13-ad95-4c00-8329-a0b1d023c289
addresses           : ["10.132.3.76", "10.135.0.44"]
external_ids        : {direction=Egress, gress-index="4", ip-family=v4, "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Egress:4:v4", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy}
name                : a5972452606168369118

_uuid               : 0c53e917-f7ee-4256-8f3a-9522c0481e52
addresses           : ["10.132.0.10", "10.132.0.11", "10.132.0.12", "10.132.0.13", "10.132.0.14", "10.132.0.15", "10.132.0.16", "10.132.0.17", "10.132.0.5", "10.132.0.7", "10.132.0.71", "10.132.0.75", "10.132.0.8", "10.132.0.81", "10.132.0.9", "10.132.2.10", "10.132.2.11", "10.132.2.12", "10.132.2.14", "10.132.2.15", "10.132.2.3", "10.132.2.4", "10.132.2.5", "10.132.2.6", "10.132.2.7", "10.132.2.8", "10.132.2.9", "10.132.3.64", "10.132.3.65", "10.132.3.72", "10.132.3.73", "10.132.3.76", "10.133.0.10", "10.133.0.11", "10.133.0.12", "10.133.0.13", "10.133.0.14", "10.133.0.15", "10.133.0.16", "10.133.0.17", "10.133.0.18", "10.133.0.19", "10.133.0.20", "10.133.0.21", "10.133.0.22", "10.133.0.23", "10.133.0.24", "10.133.0.25", "10.133.0.26", "10.133.0.27", "10.133.0.28", "10.133.0.29", "10.133.0.30", "10.133.0.31", "10.133.0.32", "10.133.0.33", "10.133.0.34", "10.133.0.35", "10.133.0.36", "10.133.0.37", "10.133.0.38", "10.133.0.39", "10.133.0.40", "10.133.0.41", "10.133.0.42", "10.133.0.44", "10.133.0.45", "10.133.0.46", "10.133.0.47", "10.133.0.48", "10.133.0.5", "10.133.0.6", "10.133.0.7", "10.133.0.8", "10.133.0.9", "10.134.0.10", "10.134.0.11", "10.134.0.12", "10.134.0.13", "10.134.0.14", "10.134.0.15", "10.134.0.16", "10.134.0.17", "10.134.0.18", "10.134.0.19", "10.134.0.20", "10.134.0.21", "10.134.0.22", "10.134.0.23", "10.134.0.24", "10.134.0.25", "10.134.0.26", "10.134.0.27", "10.134.0.28", "10.134.0.30", "10.134.0.31", "10.134.0.32", "10.134.0.33", "10.134.0.34", "10.134.0.35", "10.134.0.36", "10.134.0.37", "10.134.0.38", "10.134.0.4", "10.134.0.42", "10.134.0.9", "10.135.0.10", "10.135.0.11", "10.135.0.12", "10.135.0.13", "10.135.0.14", "10.135.0.15", "10.135.0.16", "10.135.0.17", "10.135.0.18", "10.135.0.19", "10.135.0.23", "10.135.0.24", "10.135.0.26", "10.135.0.27", "10.135.0.29", "10.135.0.3", "10.135.0.4", "10.135.0.40", "10.135.0.41", "10.135.0.42", "10.135.0.43", "10.135.0.44", "10.135.0.5", "10.135.0.6", "10.135.0.7", "10.135.0.8", "10.135.0.9"]
external_ids        : {direction=Egress, gress-index="2", ip-family=v4, "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Egress:2:v4", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy}
name                : a18396736153283155648

_uuid               : 5228bf1b-dfd8-40ec-bfa8-95c5bf9aded9
addresses           : []
external_ids        : {direction=Ingress, gress-index="0", ip-family=v4, "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Ingress:0:v4", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy}
name                : a14545668191619617708

_uuid               : 46530d69-70da-4558-8c63-884ec9dc4f25
addresses           : ["10.132.2.10", "10.132.2.5", "10.132.2.6", "10.132.2.7", "10.132.2.8", "10.132.2.9", "10.133.0.47", "10.134.0.33", "10.135.0.10", "10.135.0.11", "10.135.0.12", "10.135.0.19", "10.135.0.24", "10.135.0.7", "10.135.0.8", "10.135.0.9"]
external_ids        : {direction=Ingress, gress-index="1", ip-family=v4, "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Ingress:1:v4", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy}
name                : a6786643370959569281

_uuid               : 65fdcdea-0b9f-4318-9884-1b51d231ad1d
addresses           : ["10.132.3.72", "10.135.0.42"]
external_ids        : {direction=Ingress, gress-index="2", ip-family=v4, "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Ingress:2:v4", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy}
name                : a13730899355151937870

_uuid               : 73eabdb0-36bf-4ca3-b66d-156ac710df4c
addresses           : ["10.0.32.0/19", "10.0.56.38/32", "10.0.69.0/24", "10.132.3.72", "10.135.0.42", "172.29.0.0/30", "192.168.194.103", "192.168.194.2"]
external_ids        : {direction=Egress, gress-index="3", ip-family=v4, "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Egress:3:v4", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy}
name                : a10622494091691694581

_uuid               : 50cdbef2-71b5-474b-914c-6fcd1d7712d3
addresses           : ["10.132.0.10", "10.132.0.11", "10.132.0.12", "10.132.0.13", "10.132.0.14", "10.132.0.15", "10.132.0.16", "10.132.0.17", "10.132.0.5", "10.132.0.7", "10.132.0.71", "10.132.0.75", "10.132.0.8", "10.132.0.81", "10.132.0.9", "10.132.2.10", "10.132.2.11", "10.132.2.12", "10.132.2.14", "10.132.2.15", "10.132.2.3", "10.132.2.4", "10.132.2.5", "10.132.2.6", "10.132.2.7", "10.132.2.8", "10.132.2.9", "10.132.3.64", "10.132.3.65", "10.132.3.72", "10.132.3.73", "10.132.3.76", "10.133.0.10", "10.133.0.11", "10.133.0.12", "10.133.0.13", "10.133.0.14", "10.133.0.15", "10.133.0.16", "10.133.0.17", "10.133.0.18", "10.133.0.19", "10.133.0.20", "10.133.0.21", "10.133.0.22", "10.133.0.23", "10.133.0.24", "10.133.0.25", "10.133.0.26", "10.133.0.27", "10.133.0.28", "10.133.0.29", "10.133.0.30", "10.133.0.31", "10.133.0.32", "10.133.0.33", "10.133.0.34", "10.133.0.35", "10.133.0.36", "10.133.0.37", "10.133.0.38", "10.133.0.39", "10.133.0.40", "10.133.0.41", "10.133.0.42", "10.133.0.44", "10.133.0.45", "10.133.0.46", "10.133.0.47", "10.133.0.48", "10.133.0.5", "10.133.0.6", "10.133.0.7", "10.133.0.8", "10.133.0.9", "10.134.0.10", "10.134.0.11", "10.134.0.12", "10.134.0.13", "10.134.0.14", "10.134.0.15", "10.134.0.16", "10.134.0.17", "10.134.0.18", "10.134.0.19", "10.134.0.20", "10.134.0.21", "10.134.0.22", "10.134.0.23", "10.134.0.24", "10.134.0.25", "10.134.0.26", "10.134.0.27", "10.134.0.28", "10.134.0.30", "10.134.0.31", "10.134.0.32", "10.134.0.33", "10.134.0.34", "10.134.0.35", "10.134.0.36", "10.134.0.37", "10.134.0.38", "10.134.0.4", "10.134.0.42", "10.134.0.9", "10.135.0.10", "10.135.0.11", "10.135.0.12", "10.135.0.13", "10.135.0.14", "10.135.0.15", "10.135.0.16", "10.135.0.17", "10.135.0.18", "10.135.0.19", "10.135.0.23", "10.135.0.24", "10.135.0.26", "10.135.0.27", "10.135.0.29", "10.135.0.3", "10.135.0.4", "10.135.0.40", "10.135.0.41", "10.135.0.42", "10.135.0.43", "10.135.0.44", "10.135.0.5", "10.135.0.6", "10.135.0.7", "10.135.0.8", "10.135.0.9"]
external_ids        : {direction=Egress, gress-index="0", ip-family=v4, "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Egress:0:v4", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy}
name                : a13517855690389298082

_uuid               : 32a42f32-2d11-43dd-979d-a56d7ee6aa57
addresses           : ["10.132.3.76", "10.135.0.44"]
external_ids        : {direction=Ingress, gress-index="3", ip-family=v4, "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Ingress:3:v4", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy}
name                : a764182844364804195

_uuid               : 8fd3b977-6e1c-47aa-82b7-e3e3136c4a72
addresses           : ["0.0.0.0/0"]
external_ids        : {direction=Egress, gress-index="5", ip-family=v4, "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Egress:5:v4", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy}
name                : a11452480169090787059

    1. Examine the specific address set of the rule by running the following command: 

      $ ovn-nbctl find Address_Set 'external_ids{>=}{"k8s.ovn.org/owner-type"=AdminNetworkPolicy,direction=Egress,"k8s.ovn.org/name"=cluster-control,gress-index="5"}'

      Example 7.17. Example outputs for Address_Set

      _uuid               : 8fd3b977-6e1c-47aa-82b7-e3e3136c4a72
addresses           : ["0.0.0.0/0"]
external_ids        : {direction=Egress, gress-index="5", ip-family=v4, "k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control:Egress:5:v4", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy}
name                : a11452480169090787059

  5. Run the following command to look at the port groups in the nbdb: 

    $ ovn-nbctl find Port_Group 'external_ids{>=}{"k8s.ovn.org/owner-type"=AdminNetworkPolicy,"k8s.ovn.org/name"=cluster-control}'

    Example 7.18. Example outputs for Port_Group

    _uuid               : f50acf71-7488-4b9a-b7b8-c8a024e99d21
acls                : [04f20275-c410-405c-a923-0e677f767889, 0d5e4722-b608-4bb1-b625-23c323cc9926, 1a27d30e-3f96-4915-8ddd-ade7f22c117b, 1a68a5ed-e7f9-47d0-b55c-89184d97e81a, 4b5d836a-e0a3-4088-825e-f9f0ca58e538, 5a6e5bb4-36eb-4209-b8bc-c611983d4624, 5d09957d-d2cc-4f5a-9ddd-b97d9d772023, aa1a224d-7960-4952-bdfb-35246bafbac8, b23a087f-08f8-4225-8c27-4a9a9ee0c407, b7be6472-df67-439c-8c9c-f55929f0a6e0, d14ed5cf-2e06-496e-8cae-6b76d5dd5ccd]
external_ids        : {"k8s.ovn.org/id"="default-network-controller:AdminNetworkPolicy:cluster-control", "k8s.ovn.org/name"=cluster-control, "k8s.ovn.org/owner-controller"=default-network-controller, "k8s.ovn.org/owner-type"=AdminNetworkPolicy}
name                : a14645450421485494999
ports               : [5e75f289-8273-4f8a-8798-8c10f7318833, de7e1b71-6184-445d-93e7-b20acadf41ea]

7.2.5.2. Additional resources

7.3. Network policy

7.3.1. About network policy

As a developer, you can define network policies that restrict traffic to pods in your cluster.

7.3.1.1. About network policy

In a cluster using a network plugin that supports Kubernetes network policy, network isolation is controlled entirely by NetworkPolicy objects. In OpenShift Container Platform 4.16, OpenShift SDN supports using network policy in its default network isolation mode.

Warning

Network policy does not apply to the host network namespace. Pods with host networking enabled are unaffected by network policy rules. However, pods connecting to the host-networked pods might be affected by the network policy rules.

Network policies cannot block traffic from localhost or from their resident nodes.

By default, all pods in a project are accessible from other pods and network endpoints. To isolate one or more pods in a project, you can create NetworkPolicy objects in that project to indicate the allowed incoming connections. Project administrators can create and delete NetworkPolicy objects within their own project.

If a pod is matched by selectors in one or more NetworkPolicy objects, then the pod will accept only connections that are allowed by at least one of those NetworkPolicy objects. A pod that is not selected by any NetworkPolicy objects is fully accessible.

A network policy applies to only the TCP, UDP, ICMP, and SCTP protocols. Other protocols are not affected.

The following example NetworkPolicy objects demonstrate supporting different scenarios:

  • Deny all traffic:

    To make a project deny by default, add a NetworkPolicy object that matches all pods but accepts no traffic: 

    kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  name: deny-by-default
spec:
  podSelector: {}
  ingress: []

  • Only allow connections from the OpenShift Container Platform Ingress Controller:

    To make a project allow only connections from the OpenShift Container Platform Ingress Controller, add the following NetworkPolicy object. 

    apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-from-openshift-ingress
spec:
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
          network.openshift.io/policy-group: ingress
  podSelector: {}
  policyTypes:
  - Ingress

  • Only accept connections from pods within a project:

    Important

    To allow ingress connections from hostNetwork pods in the same namespace, you need to apply the allow-from-hostnetwork policy together with the allow-same-namespace policy.

    To make pods accept connections from other pods in the same project, but reject all other connections from pods in other projects, add the following NetworkPolicy object: 

    kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  name: allow-same-namespace
spec:
  podSelector: {}
  ingress:
  - from:
    - podSelector: {}

  • Only allow HTTP and HTTPS traffic based on pod labels:

    To enable only HTTP and HTTPS access to the pods with a specific label (role=frontend in following example), add a NetworkPolicy object similar to the following: 

    kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  name: allow-http-and-https
spec:
  podSelector:
    matchLabels:
      role: frontend
  ingress:
  - ports:
    - protocol: TCP
      port: 80
    - protocol: TCP
      port: 443

  • Accept connections by using both namespace and pod selectors:

    To match network traffic by combining namespace and pod selectors, you can use a NetworkPolicy object similar to the following: 

    kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  name: allow-pod-and-namespace-both
spec:
  podSelector:
    matchLabels:
      name: test-pods
  ingress:
    - from:
      - namespaceSelector:
          matchLabels:
            project: project_name
        podSelector:
          matchLabels:
            name: test-pods

NetworkPolicy objects are additive, which means you can combine multiple NetworkPolicy objects together to satisfy complex network requirements.

For example, for the NetworkPolicy objects defined in previous samples, you can define both allow-same-namespace and allow-http-and-https policies within the same project. Thus allowing the pods with the label role=frontend, to accept any connection allowed by each policy. That is, connections on any port from pods in the same namespace, and connections on ports 80 and 443 from pods in any namespace.

7.3.1.1.1. Using the allow-from-router network policy

Use the following NetworkPolicy to allow external traffic regardless of the router configuration: 

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-from-router
spec:
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
          policy-group.network.openshift.io/ingress: ""1
  podSelector: {}
  policyTypes:
  - Ingress
1
policy-group.network.openshift.io/ingress:"" label supports both OpenShift-SDN and OVN-Kubernetes.
7.3.1.1.2. Using the allow-from-hostnetwork network policy

Add the following allow-from-hostnetwork NetworkPolicy object to direct traffic from the host network pods. 

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-from-hostnetwork
spec:
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
          policy-group.network.openshift.io/host-network: ""
  podSelector: {}
  policyTypes:
  - Ingress

7.3.1.2. Optimizations for network policy with OpenShift SDN

Use a network policy to isolate pods that are differentiated from one another by labels within a namespace.

It is inefficient to apply NetworkPolicy objects to large numbers of individual pods in a single namespace. Pod labels do not exist at the IP address level, so a network policy generates a separate Open vSwitch (OVS) flow rule for every possible link between every pod selected with a podSelector.

For example, if the spec podSelector and the ingress podSelector within a NetworkPolicy object each match 200 pods, then 40,000 (200*200) OVS flow rules are generated. This might slow down a node.

When designing your network policy, refer to the following guidelines:

  • Reduce the number of OVS flow rules by using namespaces to contain groups of pods that need to be isolated.

    NetworkPolicy objects that select a whole namespace, by using the namespaceSelector or an empty podSelector, generate only a single OVS flow rule that matches the VXLAN virtual network ID (VNID) of the namespace.

  • Keep the pods that do not need to be isolated in their original namespace, and move the pods that require isolation into one or more different namespaces.
  • Create additional targeted cross-namespace network policies to allow the specific traffic that you do want to allow from the isolated pods.

7.3.1.3. Optimizations for network policy with OVN-Kubernetes network plugin

When designing your network policy, refer to the following guidelines:

  • For network policies with the same spec.podSelector spec, it is more efficient to use one network policy with multiple ingress or egress rules, than multiple network policies with subsets of ingress or egress rules.

  • Every ingress or egress rule based on the podSelector or namespaceSelector spec generates the number of OVS flows proportional to number of pods selected by network policy + number of pods selected by ingress or egress rule. Therefore, it is preferable to use the podSelector or namespaceSelector spec that can select as many pods as you need in one rule, instead of creating individual rules for every pod.

    For example, the following policy contains two rules: 

    apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: test-network-policy
spec:
  podSelector: {}
  ingress:
  - from:
    - podSelector:
        matchLabels:
          role: frontend
  - from:
    - podSelector:
        matchLabels:
          role: backend

    The following policy expresses those same two rules as one: 

    apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: test-network-policy
spec:
  podSelector: {}
  ingress:
  - from:
    - podSelector:
        matchExpressions:
        - {key: role, operator: In, values: [frontend, backend]}

    The same guideline applies to the spec.podSelector spec. If you have the same ingress or egress rules for different network policies, it might be more efficient to create one network policy with a common spec.podSelector spec. For example, the following two policies have different rules: 

    apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: policy1
spec:
  podSelector:
    matchLabels:
      role: db
  ingress:
  - from:
    - podSelector:
        matchLabels:
          role: frontend
---
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: policy2
spec:
  podSelector:
    matchLabels:
      role: client
  ingress:
  - from:
    - podSelector:
        matchLabels:
          role: frontend

    The following network policy expresses those same two rules as one: 

    apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: policy3
spec:
  podSelector:
    matchExpressions:
    - {key: role, operator: In, values: [db, client]}
  ingress:
  - from:
    - podSelector:
        matchLabels:
          role: frontend

    You can apply this optimization when only multiple selectors are expressed as one. In cases where selectors are based on different labels, it may not be possible to apply this optimization. In those cases, consider applying some new labels for network policy optimization specifically.

7.3.1.4. Next steps

7.3.1.5. Additional resources

7.3.2. Creating a network policy

As a user with the admin role, you can create a network policy for a namespace.

7.3.2.1. Example NetworkPolicy object

The following annotates an example NetworkPolicy object: 

kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  name: allow-27107 1
spec:
  podSelector: 2
    matchLabels:
      app: mongodb
  ingress:
  - from:
    - podSelector: 3
        matchLabels:
          app: app
    ports: 4
    - protocol: TCP
      port: 27017
1
The name of the NetworkPolicy object.
2
A selector that describes the pods to which the policy applies. The policy object can only select pods in the project that defines the NetworkPolicy object.
3
A selector that matches the pods from which the policy object allows ingress traffic. The selector matches pods in the same namespace as the NetworkPolicy.
4
A list of one or more destination ports on which to accept traffic.

7.3.2.2. Creating a network policy using the CLI

To define granular rules describing ingress or egress network traffic allowed for namespaces in your cluster, you can create a network policy.

Note

If you log in with a user with the cluster-admin role, then you can create a network policy in any namespace in the cluster.

Prerequisites

  • Your cluster uses a network plugin that supports NetworkPolicy objects, such as the OVN-Kubernetes network plugin or the OpenShift SDN network plugin with mode: NetworkPolicy set. This mode is the default for OpenShift SDN.
  • You installed the OpenShift CLI (oc).
  • You are logged in to the cluster with a user with admin privileges.
  • You are working in the namespace that the network policy applies to.

Procedure

  1. Create a policy rule:

    1. Create a <policy_name>.yaml file: 

      $ touch <policy_name>.yaml

      where:

      <policy_name>
      Specifies the network policy file name.

    2. Define a network policy in the file that you just created, such as in the following examples:

      Deny ingress from all pods in all namespaces

      This is a fundamental policy, blocking all cross-pod networking other than cross-pod traffic allowed by the configuration of other Network Policies. 

      kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  name: deny-by-default
spec:
  podSelector: {}
  policyTypes:
  - Ingress
  ingress: []

      Allow ingress from all pods in the same namespace

      kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  name: allow-same-namespace
spec:
  podSelector:
  ingress:
  - from:
    - podSelector: {}

      Allow ingress traffic to one pod from a particular namespace

      This policy allows traffic to pods labelled pod-a from pods running in namespace-y. 

      kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  name: allow-traffic-pod
spec:
  podSelector:
   matchLabels:
      pod: pod-a
  policyTypes:
  - Ingress
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
           kubernetes.io/metadata.name: namespace-y

  2. To create the network policy object, enter the following command: 

    $ oc apply -f <policy_name>.yaml -n <namespace>

    where:

    <policy_name>
    Specifies the network policy file name.
    <namespace>
    Optional: Specifies the namespace if the object is defined in a different namespace than the current namespace.

    Example output

    networkpolicy.networking.k8s.io/deny-by-default created

Note

If you log in to the web console with cluster-admin privileges, you have a choice of creating a network policy in any namespace in the cluster directly in YAML or from a form in the web console.

7.3.2.3. Creating a default deny all network policy

This is a fundamental policy, blocking all cross-pod networking other than network traffic allowed by the configuration of other deployed network policies. This procedure enforces a default deny-by-default policy.

Note

If you log in with a user with the cluster-admin role, then you can create a network policy in any namespace in the cluster.

Prerequisites

  • Your cluster uses a network plugin that supports NetworkPolicy objects, such as the OVN-Kubernetes network plugin or the OpenShift SDN network plugin with mode: NetworkPolicy set. This mode is the default for OpenShift SDN.
  • You installed the OpenShift CLI (oc).
  • You are logged in to the cluster with a user with admin privileges.
  • You are working in the namespace that the network policy applies to.

Procedure

  1. Create the following YAML that defines a deny-by-default policy to deny ingress from all pods in all namespaces. Save the YAML in the deny-by-default.yaml file: 

    kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  name: deny-by-default
  namespace: default 1
spec:
  podSelector: {} 2
  ingress: [] 3
    1
    namespace: default deploys this policy to the default namespace.
    2
    podSelector: is empty, this means it matches all the pods. Therefore, the policy applies to all pods in the default namespace.
    3
    There are no ingress rules specified. This causes incoming traffic to be dropped to all pods.

  2. Apply the policy by entering the following command: 

    $ oc apply -f deny-by-default.yaml

    Example output

    networkpolicy.networking.k8s.io/deny-by-default created

7.3.2.4. Creating a network policy to allow traffic from external clients

With the deny-by-default policy in place you can proceed to configure a policy that allows traffic from external clients to a pod with the label app=web.

Note

If you log in with a user with the cluster-admin role, then you can create a network policy in any namespace in the cluster.

Follow this procedure to configure a policy that allows external service from the public Internet directly or by using a Load Balancer to access the pod. Traffic is only allowed to a pod with the label app=web.

Prerequisites

  • Your cluster uses a network plugin that supports NetworkPolicy objects, such as the OVN-Kubernetes network plugin or the OpenShift SDN network plugin with mode: NetworkPolicy set. This mode is the default for OpenShift SDN.
  • You installed the OpenShift CLI (oc).
  • You are logged in to the cluster with a user with admin privileges.
  • You are working in the namespace that the network policy applies to.

Procedure

  1. Create a policy that allows traffic from the public Internet directly or by using a load balancer to access the pod. Save the YAML in the web-allow-external.yaml file: 

    kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  name: web-allow-external
  namespace: default
spec:
  policyTypes:
  - Ingress
  podSelector:
    matchLabels:
      app: web
  ingress:
    - {}

  2. Apply the policy by entering the following command: 

    $ oc apply -f web-allow-external.yaml

    Example output

    networkpolicy.networking.k8s.io/web-allow-external created

    This policy allows traffic from all resources, including external traffic as illustrated in the following diagram:

Allow traffic from external clients

7.3.2.5. Creating a network policy allowing traffic to an application from all namespaces

Note

If you log in with a user with the cluster-admin role, then you can create a network policy in any namespace in the cluster.

Follow this procedure to configure a policy that allows traffic from all pods in all namespaces to a particular application.

Prerequisites

  • Your cluster uses a network plugin that supports NetworkPolicy objects, such as the OVN-Kubernetes network plugin or the OpenShift SDN network plugin with mode: NetworkPolicy set. This mode is the default for OpenShift SDN.
  • You installed the OpenShift CLI (oc).
  • You are logged in to the cluster with a user with admin privileges.
  • You are working in the namespace that the network policy applies to.

Procedure

  1. Create a policy that allows traffic from all pods in all namespaces to a particular application. Save the YAML in the web-allow-all-namespaces.yaml file: 

    kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  name: web-allow-all-namespaces
  namespace: default
spec:
  podSelector:
    matchLabels:
      app: web 1
  policyTypes:
  - Ingress
  ingress:
  - from:
    - namespaceSelector: {} 2
    1
    Applies the policy only to app:web pods in default namespace.
    2
    Selects all pods in all namespaces.
    Note

    By default, if you omit specifying a namespaceSelector it does not select any namespaces, which means the policy allows traffic only from the namespace the network policy is deployed to.

  2. Apply the policy by entering the following command: 

    $ oc apply -f web-allow-all-namespaces.yaml

    Example output

    networkpolicy.networking.k8s.io/web-allow-all-namespaces created

Verification

  1. Start a web service in the default namespace by entering the following command: 

    $ oc run web --namespace=default --image=nginx --labels="app=web" --expose --port=80

  2. Run the following command to deploy an alpine image in the secondary namespace and to start a shell: 

    $ oc run test-$RANDOM --namespace=secondary --rm -i -t --image=alpine -- sh

  3. Run the following command in the shell and observe that the request is allowed: 

    # wget -qO- --timeout=2 http://web.default

    Expected output

    <!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

7.3.2.6. Creating a network policy allowing traffic to an application from a namespace

Note

If you log in with a user with the cluster-admin role, then you can create a network policy in any namespace in the cluster.

Follow this procedure to configure a policy that allows traffic to a pod with the label app=web from a particular namespace. You might want to do this to:

  • Restrict traffic to a production database only to namespaces where production workloads are deployed.
  • Enable monitoring tools deployed to a particular namespace to scrape metrics from the current namespace.

Prerequisites

  • Your cluster uses a network plugin that supports NetworkPolicy objects, such as the OVN-Kubernetes network plugin or the OpenShift SDN network plugin with mode: NetworkPolicy set. This mode is the default for OpenShift SDN.
  • You installed the OpenShift CLI (oc).
  • You are logged in to the cluster with a user with admin privileges.
  • You are working in the namespace that the network policy applies to.

Procedure

  1. Create a policy that allows traffic from all pods in a particular namespaces with a label purpose=production. Save the YAML in the web-allow-prod.yaml file: 

    kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  name: web-allow-prod
  namespace: default
spec:
  podSelector:
    matchLabels:
      app: web 1
  policyTypes:
  - Ingress
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
          purpose: production 2
    1
    Applies the policy only to app:web pods in the default namespace.
    2
    Restricts traffic to only pods in namespaces that have the label purpose=production.

  2. Apply the policy by entering the following command: 

    $ oc apply -f web-allow-prod.yaml

    Example output

    networkpolicy.networking.k8s.io/web-allow-prod created

Verification

  1. Start a web service in the default namespace by entering the following command: 

    $ oc run web --namespace=default --image=nginx --labels="app=web" --expose --port=80

  2. Run the following command to create the prod namespace: 

    $ oc create namespace prod

  3. Run the following command to label the prod namespace: 

    $ oc label namespace/prod purpose=production

  4. Run the following command to create the dev namespace: 

    $ oc create namespace dev

  5. Run the following command to label the dev namespace: 

    $ oc label namespace/dev purpose=testing

  6. Run the following command to deploy an alpine image in the dev namespace and to start a shell: 

    $ oc run test-$RANDOM --namespace=dev --rm -i -t --image=alpine -- sh

  7. Run the following command in the shell and observe that the request is blocked: 

    # wget -qO- --timeout=2 http://web.default

    Expected output

    wget: download timed out

  8. Run the following command to deploy an alpine image in the prod namespace and start a shell: 

    $ oc run test-$RANDOM --namespace=prod --rm -i -t --image=alpine -- sh

  9. Run the following command in the shell and observe that the request is allowed: 

    # wget -qO- --timeout=2 http://web.default

    Expected output

    <!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

7.3.2.7. Additional resources

7.3.3. Viewing a network policy

As a user with the admin role, you can view a network policy for a namespace.

7.3.3.1. Example NetworkPolicy object

The following annotates an example NetworkPolicy object: 

kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  name: allow-27107 1
spec:
  podSelector: 2
    matchLabels:
      app: mongodb
  ingress:
  - from:
    - podSelector: 3
        matchLabels:
          app: app
    ports: 4
    - protocol: TCP
      port: 27017
1
The name of the NetworkPolicy object.
2
A selector that describes the pods to which the policy applies. The policy object can only select pods in the project that defines the NetworkPolicy object.
3
A selector that matches the pods from which the policy object allows ingress traffic. The selector matches pods in the same namespace as the NetworkPolicy.
4
A list of one or more destination ports on which to accept traffic.

7.3.3.2. Viewing network policies using the CLI

You can examine the network policies in a namespace.

Note

If you log in with a user with the cluster-admin role, then you can view any network policy in the cluster.

Prerequisites

  • You installed the OpenShift CLI (oc).
  • You are logged in to the cluster with a user with admin privileges.
  • You are working in the namespace where the network policy exists.

Procedure

  • List network policies in a namespace:

    • To view network policy objects defined in a namespace, enter the following command: 

      $ oc get networkpolicy

    • Optional: To examine a specific network policy, enter the following command: 

      $ oc describe networkpolicy <policy_name> -n <namespace>

      where:

      <policy_name>
      Specifies the name of the network policy to inspect.
      <namespace>
      Optional: Specifies the namespace if the object is defined in a different namespace than the current namespace.

      For example: 

      $ oc describe networkpolicy allow-same-namespace

      Output for oc describe command

      Name:         allow-same-namespace
Namespace:    ns1
Created on:   2021-05-24 22:28:56 -0400 EDT
Labels:       <none>
Annotations:  <none>
Spec:
  PodSelector:     <none> (Allowing the specific traffic to all pods in this namespace)
  Allowing ingress traffic:
    To Port: <any> (traffic allowed to all ports)
    From:
      PodSelector: <none>
  Not affecting egress traffic
  Policy Types: Ingress

Note

If you log in to the web console with cluster-admin privileges, you have a choice of viewing a network policy in any namespace in the cluster directly in YAML or from a form in the web console.

7.3.4. Editing a network policy

As a user with the admin role, you can edit an existing network policy for a namespace.

7.3.4.1. Editing a network policy

You can edit a network policy in a namespace.

Note

If you log in with a user with the cluster-admin role, then you can edit a network policy in any namespace in the cluster.

Prerequisites

  • Your cluster uses a network plugin that supports NetworkPolicy objects, such as the OVN-Kubernetes network plugin or the OpenShift SDN network plugin with mode: NetworkPolicy set. This mode is the default for OpenShift SDN.
  • You installed the OpenShift CLI (oc).
  • You are logged in to the cluster with a user with admin privileges.
  • You are working in the namespace where the network policy exists.

Procedure

  1. Optional: To list the network policy objects in a namespace, enter the following command: 

    $ oc get networkpolicy

    where:

    <namespace>
    Optional: Specifies the namespace if the object is defined in a different namespace than the current namespace.

  2. Edit the network policy object.

    • If you saved the network policy definition in a file, edit the file and make any necessary changes, and then enter the following command. 

      $ oc apply -n <namespace> -f <policy_file>.yaml

      where:

      <namespace>
      Optional: Specifies the namespace if the object is defined in a different namespace than the current namespace.
      <policy_file>
      Specifies the name of the file containing the network policy.

    • If you need to update the network policy object directly, enter the following command: 

      $ oc edit networkpolicy <policy_name> -n <namespace>

      where:

      <policy_name>
      Specifies the name of the network policy.
      <namespace>
      Optional: Specifies the namespace if the object is defined in a different namespace than the current namespace.

  3. Confirm that the network policy object is updated. 

    $ oc describe networkpolicy <policy_name> -n <namespace>

    where:

    <policy_name>
    Specifies the name of the network policy.
    <namespace>
    Optional: Specifies the namespace if the object is defined in a different namespace than the current namespace.
Note

If you log in to the web console with cluster-admin privileges, you have a choice of editing a network policy in any namespace in the cluster directly in YAML or from the policy in the web console through the Actions menu.

7.3.4.2. Example NetworkPolicy object

The following annotates an example NetworkPolicy object: 

kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  name: allow-27107 1
spec:
  podSelector: 2
    matchLabels:
      app: mongodb
  ingress:
  - from:
    - podSelector: 3
        matchLabels:
          app: app
    ports: 4
    - protocol: TCP
      port: 27017
1
The name of the NetworkPolicy object.
2
A selector that describes the pods to which the policy applies. The policy object can only select pods in the project that defines the NetworkPolicy object.
3
A selector that matches the pods from which the policy object allows ingress traffic. The selector matches pods in the same namespace as the NetworkPolicy.
4
A list of one or more destination ports on which to accept traffic.

7.3.4.3. Additional resources

7.3.5. Deleting a network policy

As a user with the admin role, you can delete a network policy from a namespace.

7.3.5.1. Deleting a network policy using the CLI

You can delete a network policy in a namespace.

Note

If you log in with a user with the cluster-admin role, then you can delete any network policy in the cluster.

Prerequisites

  • Your cluster uses a network plugin that supports NetworkPolicy objects, such as the OVN-Kubernetes network plugin or the OpenShift SDN network plugin with mode: NetworkPolicy set. This mode is the default for OpenShift SDN.
  • You installed the OpenShift CLI (oc).
  • You are logged in to the cluster with a user with admin privileges.
  • You are working in the namespace where the network policy exists.

Procedure

  • To delete a network policy object, enter the following command: 

    $ oc delete networkpolicy <policy_name> -n <namespace>

    where:

    <policy_name>
    Specifies the name of the network policy.
    <namespace>
    Optional: Specifies the namespace if the object is defined in a different namespace than the current namespace.

    Example output

    networkpolicy.networking.k8s.io/default-deny deleted

Note

If you log in to the web console with cluster-admin privileges, you have a choice of deleting a network policy in any namespace in the cluster directly in YAML or from the policy in the web console through the Actions menu.

7.3.6. Defining a default network policy for projects

As a cluster administrator, you can modify the new project template to automatically include network policies when you create a new project. If you do not yet have a customized template for new projects, you must first create one.

7.3.6.1. Modifying the template for new projects

As a cluster administrator, you can modify the default project template so that new projects are created using your custom requirements.

To create your own custom project template:

Prerequisites

  • You have access to an OpenShift Container Platform cluster using an account with cluster-admin permissions.

Procedure

  1. Log in as a user with cluster-admin privileges.

  2. Generate the default project template: 

    $ oc adm create-bootstrap-project-template -o yaml > template.yaml
  3. Use a text editor to modify the generated template.yaml file by adding objects or modifying existing objects.

  4. The project template must be created in the openshift-config namespace. Load your modified template: 

    $ oc create -f template.yaml -n openshift-config

  5. Edit the project configuration resource using the web console or CLI.

    • Using the web console:

      1. Navigate to the Administration Cluster Settings page.
      2. Click Configuration to view all configuration resources.
      3. Find the entry for Project and click Edit YAML.

    • Using the CLI:

      1. Edit the project.config.openshift.io/cluster resource: 

        $ oc edit project.config.openshift.io/cluster

  6. Update the spec section to include the projectRequestTemplate and name parameters, and set the name of your uploaded project template. The default name is project-request.

    Project configuration resource with custom project template

    apiVersion: config.openshift.io/v1
kind: Project
metadata:
# ...
spec:
  projectRequestTemplate:
    name: <template_name>
# ...

  7. After you save your changes, create a new project to verify that your changes were successfully applied.

7.3.6.2. Adding network policies to the new project template

As a cluster administrator, you can add network policies to the default template for new projects. OpenShift Container Platform will automatically create all the NetworkPolicy objects specified in the template in the project.

Prerequisites

  • Your cluster uses a default CNI network plugin that supports NetworkPolicy objects, such as the OpenShift SDN network plugin with mode: NetworkPolicy set. This mode is the default for OpenShift SDN.
  • You installed the OpenShift CLI (oc).
  • You must log in to the cluster with a user with cluster-admin privileges.
  • You must have created a custom default project template for new projects.

Procedure

  1. Edit the default template for a new project by running the following command: 

    $ oc edit template <project_template> -n openshift-config

    Replace <project_template> with the name of the default template that you configured for your cluster. The default template name is project-request.

  2. In the template, add each NetworkPolicy object as an element to the objects parameter. The objects parameter accepts a collection of one or more objects.

    In the following example, the objects parameter collection includes several NetworkPolicy objects. 

    objects:
- apiVersion: networking.k8s.io/v1
  kind: NetworkPolicy
  metadata:
    name: allow-from-same-namespace
  spec:
    podSelector: {}
    ingress:
    - from:
      - podSelector: {}
- apiVersion: networking.k8s.io/v1
  kind: NetworkPolicy
  metadata:
    name: allow-from-openshift-ingress
  spec:
    ingress:
    - from:
      - namespaceSelector:
          matchLabels:
            network.openshift.io/policy-group: ingress
    podSelector: {}
    policyTypes:
    - Ingress
- apiVersion: networking.k8s.io/v1
  kind: NetworkPolicy
  metadata:
    name: allow-from-kube-apiserver-operator
  spec:
    ingress:
    - from:
      - namespaceSelector:
          matchLabels:
            kubernetes.io/metadata.name: openshift-kube-apiserver-operator
        podSelector:
          matchLabels:
            app: kube-apiserver-operator
    policyTypes:
    - Ingress
...

  3. Optional: Create a new project to confirm that your network policy objects are created successfully by running the following commands:

    1. Create a new project: 

      $ oc new-project <project> 1
      1
      Replace <project> with the name for the project you are creating.

    2. Confirm that the network policy objects in the new project template exist in the new project: 

      $ oc get networkpolicy
NAME                           POD-SELECTOR   AGE
allow-from-openshift-ingress   <none>         7s
allow-from-same-namespace      <none>         7s

7.3.7. Configuring multitenant isolation with network policy

As a cluster administrator, you can configure your network policies to provide multitenant network isolation.

Note

If you are using the OpenShift SDN network plugin, configuring network policies as described in this section provides network isolation similar to multitenant mode but with network policy mode set.

7.3.7.1. Configuring multitenant isolation by using network policy

You can configure your project to isolate it from pods and services in other project namespaces.

Prerequisites

  • Your cluster uses a network plugin that supports NetworkPolicy objects, such as the OVN-Kubernetes network plugin or the OpenShift SDN network plugin with mode: NetworkPolicy set. This mode is the default for OpenShift SDN.
  • You installed the OpenShift CLI (oc).
  • You are logged in to the cluster with a user with admin privileges.

Procedure

  1. Create the following NetworkPolicy objects:

    1. A policy named allow-from-openshift-ingress. 

      $ cat << EOF| oc create -f -
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-from-openshift-ingress
spec:
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
          policy-group.network.openshift.io/ingress: ""
  podSelector: {}
  policyTypes:
  - Ingress
EOF
      Note

      policy-group.network.openshift.io/ingress: "" is the preferred namespace selector label for OpenShift SDN. You can use the network.openshift.io/policy-group: ingress namespace selector label, but this is a legacy label.

    2. A policy named allow-from-openshift-monitoring: 

      $ cat << EOF| oc create -f -
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-from-openshift-monitoring
spec:
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
          network.openshift.io/policy-group: monitoring
  podSelector: {}
  policyTypes:
  - Ingress
EOF

    3. A policy named allow-same-namespace: 

      $ cat << EOF| oc create -f -
kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  name: allow-same-namespace
spec:
  podSelector:
  ingress:
  - from:
    - podSelector: {}
EOF

    4. A policy named allow-from-kube-apiserver-operator: 

      $ cat << EOF| oc create -f -
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-from-kube-apiserver-operator
spec:
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
          kubernetes.io/metadata.name: openshift-kube-apiserver-operator
      podSelector:
        matchLabels:
          app: kube-apiserver-operator
  policyTypes:
  - Ingress
EOF

      For more details, see New kube-apiserver-operator webhook controller validating health of webhook.

  2. Optional: To confirm that the network policies exist in your current project, enter the following command: 

    $ oc describe networkpolicy

    Example output

    Name:         allow-from-openshift-ingress
Namespace:    example1
Created on:   2020-06-09 00:28:17 -0400 EDT
Labels:       <none>
Annotations:  <none>
Spec:
  PodSelector:     <none> (Allowing the specific traffic to all pods in this namespace)
  Allowing ingress traffic:
    To Port: <any> (traffic allowed to all ports)
    From:
      NamespaceSelector: network.openshift.io/policy-group: ingress
  Not affecting egress traffic
  Policy Types: Ingress


Name:         allow-from-openshift-monitoring
Namespace:    example1
Created on:   2020-06-09 00:29:57 -0400 EDT
Labels:       <none>
Annotations:  <none>
Spec:
  PodSelector:     <none> (Allowing the specific traffic to all pods in this namespace)
  Allowing ingress traffic:
    To Port: <any> (traffic allowed to all ports)
    From:
      NamespaceSelector: network.openshift.io/policy-group: monitoring
  Not affecting egress traffic
  Policy Types: Ingress

7.3.7.2. Next steps

7.3.7.3. Additional resources

7.4. Audit logging for network security

The OVN-Kubernetes network plugin uses Open Virtual Network (OVN) access control lists (ACLs) to manage AdminNetworkPolicy, BaselineAdminNetworkPolicy, NetworkPolicy, and EgressFirewall objects. Audit logging exposes allow and deny ACL events for NetworkPolicy, EgressFirewall and BaselineAdminNetworkPolicy custom resources (CR). Logging also exposes allow, deny, and pass ACL events for AdminNetworkPolicy (ANP) CR.

Note

Audit logging is available for only the OVN-Kubernetes network plugin.

7.4.1. Audit configuration

The configuration for audit logging is specified as part of the OVN-Kubernetes cluster network provider configuration. The following YAML illustrates the default values for the audit logging:

Audit logging configuration

apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
spec:
  defaultNetwork:
    ovnKubernetesConfig:
      policyAuditConfig:
        destination: "null"
        maxFileSize: 50
        rateLimit: 20
        syslogFacility: local0

The following table describes the configuration fields for audit logging.

Table 7.1. policyAuditConfig object
FieldTypeDescription

rateLimit

integer

The maximum number of messages to generate every second per node. The default value is 20 messages per second.

maxFileSize

integer

The maximum size for the audit log in bytes. The default value is 50000000 or 50 MB.

maxLogFiles

integer

The maximum number of log files that are retained.

destination

string

One of the following additional audit log targets:

libc
The libc syslog() function of the journald process on the host.
udp:<host>:<port>
A syslog server. Replace <host>:<port> with the host and port of the syslog server.
unix:<file>
A Unix Domain Socket file specified by <file>.
null
Do not send the audit logs to any additional target.

syslogFacility

string

The syslog facility, such as kern, as defined by RFC5424. The default value is local0.

7.4.2. Audit logging

You can configure the destination for audit logs, such as a syslog server or a UNIX domain socket. Regardless of any additional configuration, an audit log is always saved to /var/log/ovn/acl-audit-log.log on each OVN-Kubernetes pod in the cluster.

You can enable audit logging for each namespace by annotating each namespace configuration with a k8s.ovn.org/acl-logging section. In the k8s.ovn.org/acl-logging section, you must specify allow, deny, or both values to enable audit logging for a namespace.

Note

A network policy does not support setting the Pass action set as a rule.

The ACL-logging implementation logs access control list (ACL) events for a network. You can view these logs to analyze any potential security issues.

Example namespace annotation

kind: Namespace
apiVersion: v1
metadata:
  name: example1
  annotations:
    k8s.ovn.org/acl-logging: |-
      {
        "deny": "info",
        "allow": "info"
      }

To view the default ACL logging configuration values, see the policyAuditConfig object in the cluster-network-03-config.yml file. If required, you can change the ACL logging configuration values for log file parameters in this file.

The logging message format is compatible with syslog as defined by RFC5424. The syslog facility is configurable and defaults to local0. The following example shows key parameters and their values outputted in a log message:

Example logging message that outputs parameters and their values

<timestamp>|<message_serial>|acl_log(ovn_pinctrl0)|<severity>|name="<acl_name>", verdict="<verdict>", severity="<severity>", direction="<direction>": <flow>

Where:

  • <timestamp> states the time and date for the creation of a log message.
  • <message_serial> lists the serial number for a log message.
  • acl_log(ovn_pinctrl0) is a literal string that prints the location of the log message in the OVN-Kubernetes plugin.
  • <severity> sets the severity level for a log message. If you enable audit logging that supports allow and deny tasks then two severity levels show in the log message output.
  • <name> states the name of the ACL-logging implementation in the OVN Network Bridging Database (nbdb) that was created by the network policy.
  • <verdict> can be either allow or drop.
  • <direction> can be either to-lport or from-lport to indicate that the policy was applied to traffic going to or away from a pod.
  • <flow> shows packet information in a format equivalent to the OpenFlow protocol. This parameter comprises Open vSwitch (OVS) fields.

The following example shows OVS fields that the flow parameter uses to extract packet information from system memory:

Example of OVS fields used by the flow parameter to extract packet information

<proto>,vlan_tci=0x0000,dl_src=<src_mac>,dl_dst=<source_mac>,nw_src=<source_ip>,nw_dst=<target_ip>,nw_tos=<tos_dscp>,nw_ecn=<tos_ecn>,nw_ttl=<ip_ttl>,nw_frag=<fragment>,tp_src=<tcp_src_port>,tp_dst=<tcp_dst_port>,tcp_flags=<tcp_flags>

Where:

  • <proto> states the protocol. Valid values are tcp and udp.
  • vlan_tci=0x0000 states the VLAN header as 0 because a VLAN ID is not set for internal pod network traffic.
  • <src_mac> specifies the source for the Media Access Control (MAC) address.
  • <source_mac> specifies the destination for the MAC address.
  • <source_ip> lists the source IP address
  • <target_ip> lists the target IP address.
  • <tos_dscp> states Differentiated Services Code Point (DSCP) values to classify and prioritize certain network traffic over other traffic.
  • <tos_ecn> states Explicit Congestion Notification (ECN) values that indicate any congested traffic in your network.
  • <ip_ttl> states the Time To Live (TTP) information for an packet.
  • <fragment> specifies what type of IP fragments or IP non-fragments to match.
  • <tcp_src_port> shows the source for the port for TCP and UDP protocols.
  • <tcp_dst_port> lists the destination port for TCP and UDP protocols.
  • <tcp_flags> supports numerous flags such as SYN, ACK, PSH and so on. If you need to set multiple values then each value is separated by a vertical bar (|). The UDP protocol does not support this parameter.
Note

For more information about the previous field descriptions, go to the OVS manual page for ovs-fields.

Example ACL deny log entry for a network policy

2023-11-02T16:28:54.139Z|00004|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:Ingress", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:01,dl_dst=0a:58:0a:81:02:23,nw_src=10.131.0.39,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=62,nw_frag=no,tp_src=58496,tp_dst=8080,tcp_flags=syn
2023-11-02T16:28:55.187Z|00005|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:Ingress", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:01,dl_dst=0a:58:0a:81:02:23,nw_src=10.131.0.39,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=62,nw_frag=no,tp_src=58496,tp_dst=8080,tcp_flags=syn
2023-11-02T16:28:57.235Z|00006|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:Ingress", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:01,dl_dst=0a:58:0a:81:02:23,nw_src=10.131.0.39,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=62,nw_frag=no,tp_src=58496,tp_dst=8080,tcp_flags=syn

The following table describes namespace annotation values:

Table 7.2. Audit logging namespace annotation for k8s.ovn.org/acl-logging
FieldDescription

deny

Blocks namespace access to any traffic that matches an ACL rule with the deny action. The field supports alert, warning, notice, info, or debug values.

allow

Permits namespace access to any traffic that matches an ACL rule with the allow action. The field supports alert, warning, notice, info, or debug values.

pass

A pass action applies to an admin network policy’s ACL rule. A pass action allows either the network policy in the namespace or the baseline admin network policy rule to evaluate all incoming and outgoing traffic. A network policy does not support a pass action.

Additional resources

7.4.3. AdminNetworkPolicy audit logging

Audit logging is enabled per AdminNetworkPolicy CR by annotating an ANP policy with the k8s.ovn.org/acl-logging key such as in the following example:

Example 7.19. Example of annotation for AdminNetworkPolicy CR

apiVersion: policy.networking.k8s.io/v1alpha1
kind: AdminNetworkPolicy
metadata:
  annotations:
    k8s.ovn.org/acl-logging: '{ "deny": "alert", "allow": "alert", "pass" : "warning" }'
  name: anp-tenant-log
spec:
  priority: 5
  subject:
    namespaces:
      matchLabels:
        tenant: backend-storage # Selects all pods owned by storage tenant.
  ingress:
    - name: "allow-all-ingress-product-development-and-customer" # Product development and customer tenant ingress to backend storage.
      action: "Allow"
      from:
      - pods:
          namespaceSelector:
            matchExpressions:
            - key: tenant
              operator: In
              values:
              - product-development
              - customer
          podSelector: {}
    - name: "pass-all-ingress-product-security"
      action: "Pass"
      from:
      - namespaces:
          matchLabels:
              tenant: product-security
    - name: "deny-all-ingress" # Ingress to backend from all other pods in the cluster.
      action: "Deny"
      from:
      - namespaces: {}
  egress:
    - name: "allow-all-egress-product-development"
      action: "Allow"
      to:
      - pods:
          namespaceSelector:
            matchLabels:
              tenant: product-development
          podSelector: {}
    - name: "pass-egress-product-security"
      action: "Pass"
      to:
      - namespaces:
           matchLabels:
             tenant: product-security
    - name: "deny-all-egress" # Egress from backend denied to all other pods.
      action: "Deny"
      to:
      - namespaces: {}

Logs are generated whenever a specific OVN ACL is hit and meets the action criteria set in your logging annotation. For example, an event in which any of the namespaces with the label tenant: product-development accesses the namespaces with the label tenant: backend-storage, a log is generated.

Note

ACL logging is limited to 60 characters. If your ANP name field is long, the rest of the log will be truncated.

The following is a direction index for the examples log entries that follow:

DirectionRule

Ingress

Rule0
Allow from tenant product-development and customer to tenant backend-storage; Ingress0: Allow
Rule1
Pass from product-security`to tenant `backend-storage; Ingress1: Pass
Rule2
Deny ingress from all pods; Ingress2: Deny

Egress

Rule0
Allow to product-development; Egress0: Allow
Rule1
Pass to product-security; Egress1: Pass
Rule2
Deny egress to all other pods; Egress2: Deny

Example 7.20. Example ACL log entry for Allow action of the AdminNetworkPolicy named anp-tenant-log with Ingress:0 and Egress:0

2024-06-10T16:27:45.194Z|00052|acl_log(ovn_pinctrl0)|INFO|name="ANP:anp-tenant-log:Ingress:0", verdict=allow, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:80:02:1a,dl_dst=0a:58:0a:80:02:19,nw_src=10.128.2.26,nw_dst=10.128.2.25,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=57814,tp_dst=8080,tcp_flags=syn
2024-06-10T16:28:23.130Z|00059|acl_log(ovn_pinctrl0)|INFO|name="ANP:anp-tenant-log:Ingress:0", verdict=allow, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:80:02:18,dl_dst=0a:58:0a:80:02:19,nw_src=10.128.2.24,nw_dst=10.128.2.25,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=38620,tp_dst=8080,tcp_flags=ack
2024-06-10T16:28:38.293Z|00069|acl_log(ovn_pinctrl0)|INFO|name="ANP:anp-tenant-log:Egress:0", verdict=allow, severity=alert, direction=from-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:80:02:19,dl_dst=0a:58:0a:80:02:1a,nw_src=10.128.2.25,nw_dst=10.128.2.26,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=47566,tp_dst=8080,tcp_flags=fin|ack=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=55704,tp_dst=8080,tcp_flags=ack

Example 7.21. Example ACL log entry for Pass action of the AdminNetworkPolicy named anp-tenant-log with Ingress:1 and Egress:1

2024-06-10T16:33:12.019Z|00075|acl_log(ovn_pinctrl0)|INFO|name="ANP:anp-tenant-log:Ingress:1", verdict=pass, severity=warning, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:80:02:1b,dl_dst=0a:58:0a:80:02:19,nw_src=10.128.2.27,nw_dst=10.128.2.25,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=37394,tp_dst=8080,tcp_flags=ack
2024-06-10T16:35:04.209Z|00081|acl_log(ovn_pinctrl0)|INFO|name="ANP:anp-tenant-log:Egress:1", verdict=pass, severity=warning, direction=from-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:80:02:19,dl_dst=0a:58:0a:80:02:1b,nw_src=10.128.2.25,nw_dst=10.128.2.27,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=34018,tp_dst=8080,tcp_flags=ack

Example 7.22. Example ACL log entry for Deny action of the AdminNetworkPolicy named anp-tenant-log with Egress:2 and Ingress2

2024-06-10T16:43:05.287Z|00087|acl_log(ovn_pinctrl0)|INFO|name="ANP:anp-tenant-log:Egress:2", verdict=drop, severity=alert, direction=from-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:80:02:19,dl_dst=0a:58:0a:80:02:18,nw_src=10.128.2.25,nw_dst=10.128.2.24,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=51598,tp_dst=8080,tcp_flags=syn
2024-06-10T16:44:43.591Z|00090|acl_log(ovn_pinctrl0)|INFO|name="ANP:anp-tenant-log:Ingress:2", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:80:02:1c,dl_dst=0a:58:0a:80:02:19,nw_src=10.128.2.28,nw_dst=10.128.2.25,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=33774,tp_dst=8080,tcp_flags=syn

The following table describes ANP annotation:

Table 7.3. Audit logging AdminNetworkPolicy annotation
AnnotationValue

k8s.ovn.org/acl-logging

You must specify at least one of Allow, Deny, or Pass to enable audit logging for a namespace.

Deny
Optional: Specify alert, warning, notice, info, or debug.
Allow
Optional: Specify alert, warning, notice, info, or debug.
Pass
Optional: Specify alert, warning, notice, info, or debug.

7.4.4. BaselineAdminNetworkPolicy audit logging

Audit logging is enabled in the BaselineAdminNetworkPolicy CR by annotating an BANP policy with the k8s.ovn.org/acl-logging key such as in the following example:

Example 7.23. Example of annotation for BaselineAdminNetworkPolicy CR

apiVersion: policy.networking.k8s.io/v1alpha1
kind: BaselineAdminNetworkPolicy
metadata:
  annotations:
    k8s.ovn.org/acl-logging: '{ "deny": "alert", "allow": "alert"}'
  name: default
spec:
  subject:
    namespaces:
      matchLabels:
          tenant: workloads # Selects all workload pods in the cluster.
  ingress:
  - name: "default-allow-dns" # This rule allows ingress from dns tenant to all workloads.
    action: "Allow"
    from:
    - namespaces:
          matchLabels:
            tenant: dns
  - name: "default-deny-dns" # This rule denies all ingress from all pods to workloads.
    action: "Deny"
    from:
    - namespaces: {} # Use the empty selector with caution because it also selects OpenShift namespaces as well.
  egress:
  - name: "default-deny-dns" # This rule denies all egress from workloads. It will be applied when no ANP or network policy matches.
    action: "Deny"
    to:
    - namespaces: {} # Use the empty selector with caution because it also selects OpenShift namespaces as well.

In the example, an event in which any of the namespaces with the label tenant: dns accesses the namespaces with the label tenant: workloads, a log is generated.

The following is a direction index for the examples log entries that follow:

DirectionRule

Ingress

Rule0
Allow from tenant dns to tenant workloads; Ingress0: Allow
Rule1
Deny to tenant workloads from all pods; Ingress1: Deny

Egress

Rule0
Deny to all pods; Egress0: Deny

Example 7.24. Example ACL allow log entry for Allow action of default BANP with Ingress:0

2024-06-10T18:11:58.263Z|00022|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:0", verdict=allow, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:57,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.87,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=60510,tp_dst=8080,tcp_flags=syn
2024-06-10T18:11:58.264Z|00023|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:0", verdict=allow, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:57,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.87,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=60510,tp_dst=8080,tcp_flags=psh|ack
2024-06-10T18:11:58.264Z|00024|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:0", verdict=allow, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:57,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.87,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=60510,tp_dst=8080,tcp_flags=ack
2024-06-10T18:11:58.264Z|00025|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:0", verdict=allow, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:57,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.87,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=60510,tp_dst=8080,tcp_flags=ack
2024-06-10T18:11:58.264Z|00026|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:0", verdict=allow, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:57,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.87,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=60510,tp_dst=8080,tcp_flags=fin|ack
2024-06-10T18:11:58.264Z|00027|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:0", verdict=allow, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:57,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.87,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=60510,tp_dst=8080,tcp_flags=ack

Example 7.25. Example ACL allow log entry for Allow action of default BANP with Egress:0 and Ingress:1

2024-06-10T18:09:57.774Z|00016|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Egress:0", verdict=drop, severity=alert, direction=from-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:56,dl_dst=0a:58:0a:82:02:57,nw_src=10.130.2.86,nw_dst=10.130.2.87,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=45614,tp_dst=8080,tcp_flags=syn
2024-06-10T18:09:58.809Z|00017|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Egress:0", verdict=drop, severity=alert, direction=from-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:56,dl_dst=0a:58:0a:82:02:57,nw_src=10.130.2.86,nw_dst=10.130.2.87,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=45614,tp_dst=8080,tcp_flags=syn
2024-06-10T18:10:00.857Z|00018|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Egress:0", verdict=drop, severity=alert, direction=from-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:56,dl_dst=0a:58:0a:82:02:57,nw_src=10.130.2.86,nw_dst=10.130.2.87,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=45614,tp_dst=8080,tcp_flags=syn
2024-06-10T18:10:25.414Z|00019|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:1", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:58,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.88,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=40630,tp_dst=8080,tcp_flags=syn
2024-06-10T18:10:26.457Z|00020|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:1", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:58,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.88,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=40630,tp_dst=8080,tcp_flags=syn
2024-06-10T18:10:28.505Z|00021|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:1", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:58,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.88,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=40630,tp_dst=8080,tcp_flags=syn

The following table describes BANP annotation:

Table 7.4. Audit logging BaselineAdminNetworkPolicy annotation
AnnotationValue

k8s.ovn.org/acl-logging

You must specify at least one of Allow or Deny to enable audit logging for a namespace.

Deny
Optional: Specify alert, warning, notice, info, or debug.
Allow
Optional: Specify alert, warning, notice, info, or debug.

7.4.5. Configuring egress firewall and network policy auditing for a cluster

As a cluster administrator, you can customize audit logging for your cluster.

Prerequisites

  • Install the OpenShift CLI (oc).
  • Log in to the cluster with a user with cluster-admin privileges.

Procedure

  • To customize the audit logging configuration, enter the following command: 

    $ oc edit network.operator.openshift.io/cluster
    Tip

    You can alternatively customize and apply the following YAML to configure audit logging: 

    apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
spec:
  defaultNetwork:
    ovnKubernetesConfig:
      policyAuditConfig:
        destination: "null"
        maxFileSize: 50
        rateLimit: 20
        syslogFacility: local0

Verification

  1. To create a namespace with network policies complete the following steps:

    1. Create a namespace for verification: 

      $ cat <<EOF| oc create -f -
kind: Namespace
apiVersion: v1
metadata:
  name: verify-audit-logging
  annotations:
    k8s.ovn.org/acl-logging: '{ "deny": "alert", "allow": "alert" }'
EOF

      Example output

      namespace/verify-audit-logging created

    2. Create network policies for the namespace: 

      $ cat <<EOF| oc create -n verify-audit-logging -f -
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: deny-all
spec:
  podSelector:
    matchLabels:
  policyTypes:
  - Ingress
  - Egress
---
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-from-same-namespace
  namespace: verify-audit-logging
spec:
  podSelector: {}
  policyTypes:
   - Ingress
   - Egress
  ingress:
    - from:
        - podSelector: {}
  egress:
    - to:
       - namespaceSelector:
          matchLabels:
            kubernetes.io/metadata.name: verify-audit-logging
EOF

      Example output

      networkpolicy.networking.k8s.io/deny-all created
networkpolicy.networking.k8s.io/allow-from-same-namespace created

  2. Create a pod for source traffic in the default namespace: 

    $ cat <<EOF| oc create -n default -f -
apiVersion: v1
kind: Pod
metadata:
  name: client
spec:
  containers:
    - name: client
      image: registry.access.redhat.com/rhel7/rhel-tools
      command: ["/bin/sh", "-c"]
      args:
        ["sleep inf"]
EOF

  3. Create two pods in the verify-audit-logging namespace: 

    $ for name in client server; do
cat <<EOF| oc create -n verify-audit-logging -f -
apiVersion: v1
kind: Pod
metadata:
  name: ${name}
spec:
  containers:
    - name: ${name}
      image: registry.access.redhat.com/rhel7/rhel-tools
      command: ["/bin/sh", "-c"]
      args:
        ["sleep inf"]
EOF
done

    Example output

    pod/client created
pod/server created

  4. To generate traffic and produce network policy audit log entries, complete the following steps:

    1. Obtain the IP address for pod named server in the verify-audit-logging namespace: 

      $ POD_IP=$(oc get pods server -n verify-audit-logging -o jsonpath='{.status.podIP}')

    2. Ping the IP address from the previous command from the pod named client in the default namespace and confirm that all packets are dropped: 

      $ oc exec -it client -n default -- /bin/ping -c 2 $POD_IP

      Example output

      PING 10.128.2.55 (10.128.2.55) 56(84) bytes of data.

--- 10.128.2.55 ping statistics ---
2 packets transmitted, 0 received, 100% packet loss, time 2041ms

    3. Ping the IP address saved in the POD_IP shell environment variable from the pod named client in the verify-audit-logging namespace and confirm that all packets are allowed: 

      $ oc exec -it client -n verify-audit-logging -- /bin/ping -c 2 $POD_IP

      Example output

      PING 10.128.0.86 (10.128.0.86) 56(84) bytes of data.
64 bytes from 10.128.0.86: icmp_seq=1 ttl=64 time=2.21 ms
64 bytes from 10.128.0.86: icmp_seq=2 ttl=64 time=0.440 ms

--- 10.128.0.86 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 0.440/1.329/2.219/0.890 ms

  5. Display the latest entries in the network policy audit log: 

    $ for pod in $(oc get pods -n openshift-ovn-kubernetes -l app=ovnkube-node --no-headers=true | awk '{ print $1 }') ; do
    oc exec -it $pod -n openshift-ovn-kubernetes -- tail -4 /var/log/ovn/acl-audit-log.log
  done

    Example output

    2023-11-02T16:28:54.139Z|00004|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:Ingress", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:01,dl_dst=0a:58:0a:81:02:23,nw_src=10.131.0.39,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=62,nw_frag=no,tp_src=58496,tp_dst=8080,tcp_flags=syn
2023-11-02T16:28:55.187Z|00005|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:Ingress", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:01,dl_dst=0a:58:0a:81:02:23,nw_src=10.131.0.39,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=62,nw_frag=no,tp_src=58496,tp_dst=8080,tcp_flags=syn
2023-11-02T16:28:57.235Z|00006|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:Ingress", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:01,dl_dst=0a:58:0a:81:02:23,nw_src=10.131.0.39,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=62,nw_frag=no,tp_src=58496,tp_dst=8080,tcp_flags=syn
2023-11-02T16:49:57.909Z|00028|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:allow-from-same-namespace:Egress:0", verdict=allow, severity=alert, direction=from-lport: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:22,dl_dst=0a:58:0a:81:02:23,nw_src=10.129.2.34,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,icmp_type=8,icmp_code=0
2023-11-02T16:49:57.909Z|00029|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:allow-from-same-namespace:Ingress:0", verdict=allow, severity=alert, direction=to-lport: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:22,dl_dst=0a:58:0a:81:02:23,nw_src=10.129.2.34,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,icmp_type=8,icmp_code=0
2023-11-02T16:49:58.932Z|00030|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:allow-from-same-namespace:Egress:0", verdict=allow, severity=alert, direction=from-lport: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:22,dl_dst=0a:58:0a:81:02:23,nw_src=10.129.2.34,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,icmp_type=8,icmp_code=0
2023-11-02T16:49:58.932Z|00031|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:allow-from-same-namespace:Ingress:0", verdict=allow, severity=alert, direction=to-lport: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:22,dl_dst=0a:58:0a:81:02:23,nw_src=10.129.2.34,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,icmp_type=8,icmp_code=0

7.4.6. Enabling egress firewall and network policy audit logging for a namespace

As a cluster administrator, you can enable audit logging for a namespace.

Prerequisites

  • Install the OpenShift CLI (oc).
  • Log in to the cluster with a user with cluster-admin privileges.

Procedure

  • To enable audit logging for a namespace, enter the following command: 

    $ oc annotate namespace <namespace> \
  k8s.ovn.org/acl-logging='{ "deny": "alert", "allow": "notice" }'

    where:

    <namespace>
    Specifies the name of the namespace.
    Tip

    You can alternatively apply the following YAML to enable audit logging: 

    kind: Namespace
apiVersion: v1
metadata:
  name: <namespace>
  annotations:
    k8s.ovn.org/acl-logging: |-
      {
        "deny": "alert",
        "allow": "notice"
      }

    Example output

    namespace/verify-audit-logging annotated

Verification

  • Display the latest entries in the audit log: 

    $ for pod in $(oc get pods -n openshift-ovn-kubernetes -l app=ovnkube-node --no-headers=true | awk '{ print $1 }') ; do
    oc exec -it $pod -n openshift-ovn-kubernetes -- tail -4 /var/log/ovn/acl-audit-log.log
  done

    Example output

    2023-11-02T16:49:57.909Z|00028|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:allow-from-same-namespace:Egress:0", verdict=allow, severity=alert, direction=from-lport: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:22,dl_dst=0a:58:0a:81:02:23,nw_src=10.129.2.34,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,icmp_type=8,icmp_code=0
2023-11-02T16:49:57.909Z|00029|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:allow-from-same-namespace:Ingress:0", verdict=allow, severity=alert, direction=to-lport: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:22,dl_dst=0a:58:0a:81:02:23,nw_src=10.129.2.34,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,icmp_type=8,icmp_code=0
2023-11-02T16:49:58.932Z|00030|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:allow-from-same-namespace:Egress:0", verdict=allow, severity=alert, direction=from-lport: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:22,dl_dst=0a:58:0a:81:02:23,nw_src=10.129.2.34,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,icmp_type=8,icmp_code=0
2023-11-02T16:49:58.932Z|00031|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:allow-from-same-namespace:Ingress:0", verdict=allow, severity=alert, direction=to-lport: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:22,dl_dst=0a:58:0a:81:02:23,nw_src=10.129.2.34,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,icmp_type=8,icmp_code=0

7.4.7. Disabling egress firewall and network policy audit logging for a namespace

As a cluster administrator, you can disable audit logging for a namespace.

Prerequisites

  • Install the OpenShift CLI (oc).
  • Log in to the cluster with a user with cluster-admin privileges.

Procedure

  • To disable audit logging for a namespace, enter the following command: 

    $ oc annotate --overwrite namespace <namespace> k8s.ovn.org/acl-logging-

    where:

    <namespace>
    Specifies the name of the namespace.
    Tip

    You can alternatively apply the following YAML to disable audit logging: 

    kind: Namespace
apiVersion: v1
metadata:
  name: <namespace>
  annotations:
    k8s.ovn.org/acl-logging: null

    Example output

    namespace/verify-audit-logging annotated

7.4.8. Additional resources

7.5. Egress Firewall

7.5.1. Viewing an egress firewall for a project

As a cluster administrator, you can list the names of any existing egress firewalls and view the traffic rules for a specific egress firewall.

Note

OpenShift SDN CNI is deprecated as of OpenShift Container Platform 4.14. As of OpenShift Container Platform 4.15, the network plugin is not an option for new installations. In a subsequent future release, the OpenShift SDN network plugin is planned to be removed and no longer supported. Red Hat will provide bug fixes and support for this feature until it is removed, but this feature will no longer receive enhancements. As an alternative to OpenShift SDN CNI, you can use OVN Kubernetes CNI instead. For more information, see OpenShift SDN CNI removal.

7.5.1.1. Viewing an EgressFirewall object

You can view an EgressFirewall object in your cluster.

Prerequisites

  • A cluster using the OVN-Kubernetes network plugin.
  • Install the OpenShift Command-line Interface (CLI), commonly known as oc.
  • You must log in to the cluster.

Procedure

  1. Optional: To view the names of the EgressFirewall objects defined in your cluster, enter the following command: 

    $ oc get egressfirewall --all-namespaces

  2. To inspect a policy, enter the following command. Replace <policy_name> with the name of the policy to inspect. 

    $ oc describe egressfirewall <policy_name>

    Example output

    Name:		default
Namespace:	project1
Created:	20 minutes ago
Labels:		<none>
Annotations:	<none>
Rule:		Allow to 1.2.3.0/24
Rule:		Allow to www.example.com
Rule:		Deny to 0.0.0.0/0

7.5.2. Editing an egress firewall for a project

As a cluster administrator, you can modify network traffic rules for an existing egress firewall.

7.5.2.1. Editing an EgressFirewall object

As a cluster administrator, you can update the egress firewall for a project.

Prerequisites

  • A cluster using the OVN-Kubernetes network plugin.
  • Install the OpenShift CLI (oc).
  • You must log in to the cluster as a cluster administrator.

Procedure

  1. Find the name of the EgressFirewall object for the project. Replace <project> with the name of the project. 

    $ oc get -n <project> egressfirewall

  2. Optional: If you did not save a copy of the EgressFirewall object when you created the egress network firewall, enter the following command to create a copy. 

    $ oc get -n <project> egressfirewall <name> -o yaml > <filename>.yaml

    Replace <project> with the name of the project. Replace <name> with the name of the object. Replace <filename> with the name of the file to save the YAML to.

  3. After making changes to the policy rules, enter the following command to replace the EgressFirewall object. Replace <filename> with the name of the file containing the updated EgressFirewall object. 

    $ oc replace -f <filename>.yaml

7.5.3. Removing an egress firewall from a project

As a cluster administrator, you can remove an egress firewall from a project to remove all restrictions on network traffic from the project that leaves the OpenShift Container Platform cluster.

7.5.3.1. Removing an EgressFirewall object

As a cluster administrator, you can remove an egress firewall from a project.

Prerequisites

  • A cluster using the OVN-Kubernetes network plugin.
  • Install the OpenShift CLI (oc).
  • You must log in to the cluster as a cluster administrator.

Procedure

  1. Find the name of the EgressFirewall object for the project. Replace <project> with the name of the project. 

    $ oc get -n <project> egressfirewall

  2. Enter the following command to delete the EgressFirewall object. Replace <project> with the name of the project and <name> with the name of the object. 

    $ oc delete -n <project> egressfirewall <name>

7.5.4. Configuring an egress firewall for a project

As a cluster administrator, you can create an egress firewall for a project that restricts egress traffic leaving your OpenShift Container Platform cluster.

7.5.4.1. How an egress firewall works in a project

As a cluster administrator, you can use an egress firewall to limit the external hosts that some or all pods can access from within the cluster. An egress firewall supports the following scenarios:

  • A pod can only connect to internal hosts and cannot initiate connections to the public internet.
  • A pod can only connect to the public internet and cannot initiate connections to internal hosts that are outside the OpenShift Container Platform cluster.
  • A pod cannot reach specified internal subnets or hosts outside the OpenShift Container Platform cluster.
  • A pod can connect to only specific external hosts.

For example, you can allow one project access to a specified IP range but deny the same access to a different project. Or you can restrict application developers from updating from Python pip mirrors, and force updates to come only from approved sources.

Note

Egress firewall does not apply to the host network namespace. Pods with host networking enabled are unaffected by egress firewall rules.

You configure an egress firewall policy by creating an EgressFirewall custom resource (CR) object. The egress firewall matches network traffic that meets any of the following criteria:

  • An IP address range in CIDR format
  • A DNS name that resolves to an IP address
  • A port number
  • A protocol that is one of the following protocols: TCP, UDP, and SCTP
Important

If your egress firewall includes a deny rule for 0.0.0.0/0, access to your OpenShift Container Platform API servers is blocked. You must either add allow rules for each IP address or use the nodeSelector type allow rule in your egress policy rules to connect to API servers.

The following example illustrates the order of the egress firewall rules necessary to ensure API server access: 

apiVersion: k8s.ovn.org/v1
kind: EgressFirewall
metadata:
  name: default
  namespace: <namespace> 1
spec:
  egress:
  - to:
      cidrSelector: <api_server_address_range> 2
    type: Allow
# ...
  - to:
      cidrSelector: 0.0.0.0/0 3
    type: Deny
1
The namespace for the egress firewall.
2
The IP address range that includes your OpenShift Container Platform API servers.
3
A global deny rule prevents access to the OpenShift Container Platform API servers.

To find the IP address for your API servers, run oc get ep kubernetes -n default.

For more information, see BZ#1988324.

Warning

Egress firewall rules do not apply to traffic that goes through routers. Any user with permission to create a Route CR object can bypass egress firewall policy rules by creating a route that points to a forbidden destination.

7.5.4.1.1. Limitations of an egress firewall

An egress firewall has the following limitations:

  • No project can have more than one EgressFirewall object.
  • A maximum of one EgressFirewall object with a maximum of 8,000 rules can be defined per project.
  • If you are using the OVN-Kubernetes network plugin with shared gateway mode in Red Hat OpenShift Networking, return ingress replies are affected by egress firewall rules. If the egress firewall rules drop the ingress reply destination IP, the traffic is dropped.

Violating any of these restrictions results in a broken egress firewall for the project. Consequently, all external network traffic is dropped, which can cause security risks for your organization.

An Egress Firewall resource can be created in the kube-node-lease, kube-public, kube-system, openshift and openshift- projects.

7.5.4.1.2. Matching order for egress firewall policy rules

The egress firewall policy rules are evaluated in the order that they are defined, from first to last. The first rule that matches an egress connection from a pod applies. Any subsequent rules are ignored for that connection.

7.5.4.1.3. How Domain Name Server (DNS) resolution works

If you use DNS names in any of your egress firewall policy rules, proper resolution of the domain names is subject to the following restrictions:

  • Domain name updates are polled based on a time-to-live (TTL) duration. By default, the duration is 30 minutes. When the egress firewall controller queries the local name servers for a domain name, if the response includes a TTL and the TTL is less than 30 minutes, the controller sets the duration for that DNS name to the returned value. Each DNS name is queried after the TTL for the DNS record expires.
  • The pod must resolve the domain from the same local name servers when necessary. Otherwise the IP addresses for the domain known by the egress firewall controller and the pod can be different. If the IP addresses for a hostname differ, the egress firewall might not be enforced consistently.
  • Because the egress firewall controller and pods asynchronously poll the same local name server, the pod might obtain the updated IP address before the egress controller does, which causes a race condition. Due to this current limitation, domain name usage in EgressFirewall objects is only recommended for domains with infrequent IP address changes.
Note

Using DNS names in your egress firewall policy does not affect local DNS resolution through CoreDNS.

However, if your egress firewall policy uses domain names, and an external DNS server handles DNS resolution for an affected pod, you must include egress firewall rules that permit access to the IP addresses of your DNS server.

7.5.4.1.3.1. Improved DNS resolution and resolving wildcard domain names

There might be situations where the IP addresses associated with a DNS record change frequently, or you might want to specify wildcard domain names in your egress firewall policy rules.

In this situation, the OVN-Kubernetes cluster manager creates a DNSNameResolver custom resource object for each unique DNS name used in your egress firewall policy rules. This custom resource stores the following information:

Important

Improved DNS resolution for egress firewall rules is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

Example DNSNameResolver CR definition

apiVersion: networking.openshift.io/v1alpha1
kind: DNSNameResolver
spec:
  name: www.example.com. 1
status:
  resolvedNames:
  - dnsName: www.example.com. 2
    resolvedAddress:
    - ip: "1.2.3.4" 3
      ttlSeconds: 60 4
      lastLookupTime: "2023-08-08T15:07:04Z" 5

1
The DNS name. This can be either a standard DNS name or a wildcard DNS name. For a wildcard DNS name, the DNS name resolution information contains all of the DNS names that match the wildcard DNS name.
2
The resolved DNS name matching the spec.name field. If the spec.name field contains a wildcard DNS name, then multiple dnsName entries are created that contain the standard DNS names that match the wildcard DNS name when resolved. If the wildcard DNS name can also be successfully resolved, then this field also stores the wildcard DNS name.
3
The current IP addresses associated with the DNS name.
4
The last time-to-live (TTL) duration.
5
The last lookup time.

If during DNS resolution the DNS name in the query matches any name defined in a DNSNameResolver CR, then the previous information is updated accordingly in the CR status field. For unsuccessful DNS wildcard name lookups, the request is retried after a default TTL of 30 minutes.

The OVN-Kubernetes cluster manager watches for updates to an EgressFirewall custom resource object, and creates, modifies, or deletes DNSNameResolver CRs associated with those egress firewall policies when that update occurs.

Warning

Do not modify DNSNameResolver custom resources directly. This can lead to unwanted behavior of your egress firewall.

7.5.4.2. EgressFirewall custom resource (CR) object

You can define one or more rules for an egress firewall. A rule is either an Allow rule or a Deny rule, with a specification for the traffic that the rule applies to.

The following YAML describes an EgressFirewall CR object:

EgressFirewall object

apiVersion: k8s.ovn.org/v1
kind: EgressFirewall
metadata:
  name: <name> 1
spec:
  egress: 2
    ...

1
The name for the object must be default.
2
A collection of one or more egress network policy rules as described in the following section.
7.5.4.2.1. EgressFirewall rules

The following YAML describes an egress firewall rule object. The user can select either an IP address range in CIDR format, a domain name, or use the nodeSelector to allow or deny egress traffic. The egress stanza expects an array of one or more objects.

Egress policy rule stanza

egress:
- type: <type> 1
  to: 2
    cidrSelector: <cidr> 3
    dnsName: <dns_name> 4
    nodeSelector: <label_name>: <label_value> 5
  ports: 6
      ...

1
The type of rule. The value must be either Allow or Deny.
2
A stanza describing an egress traffic match rule that specifies the cidrSelector field or the dnsName field. You cannot use both fields in the same rule.
3
An IP address range in CIDR format.
4
A DNS domain name.
5
Labels are key/value pairs that the user defines. Labels are attached to objects, such as pods. The nodeSelector allows for one or more node labels to be selected and attached to pods.
6
Optional: A stanza describing a collection of network ports and protocols for the rule.

Ports stanza

ports:
- port: <port> 1
  protocol: <protocol> 2

1
A network port, such as 80 or 443. If you specify a value for this field, you must also specify a value for protocol.
2
A network protocol. The value must be either TCP, UDP, or SCTP.
7.5.4.2.2. Example EgressFirewall CR objects

The following example defines several egress firewall policy rules: 

apiVersion: k8s.ovn.org/v1
kind: EgressFirewall
metadata:
  name: default
spec:
  egress: 1
  - type: Allow
    to:
      cidrSelector: 1.2.3.0/24
  - type: Deny
    to:
      cidrSelector: 0.0.0.0/0
1
A collection of egress firewall policy rule objects.

The following example defines a policy rule that denies traffic to the host at the 172.16.1.1 IP address, if the traffic is using either the TCP protocol and destination port 80 or any protocol and destination port 443. 

apiVersion: k8s.ovn.org/v1
kind: EgressFirewall
metadata:
  name: default
spec:
  egress:
  - type: Deny
    to:
      cidrSelector: 172.16.1.1
    ports:
    - port: 80
      protocol: TCP
    - port: 443
7.5.4.2.3. Example nodeSelector for EgressFirewall

As a cluster administrator, you can allow or deny egress traffic to nodes in your cluster by specifying a label using nodeSelector. Labels can be applied to one or more nodes. The following is an example with the region=east label: 

apiVersion: k8s.ovn.org/v1
kind: EgressFirewall
metadata:
  name: default
spec:
    egress:
    - to:
        nodeSelector:
          matchLabels:
            region: east
      type: Allow
Tip

Instead of adding manual rules per node IP address, use node selectors to create a label that allows pods behind an egress firewall to access host network pods.

7.5.4.3. Creating an egress firewall policy object

As a cluster administrator, you can create an egress firewall policy object for a project.

Important

If the project already has an EgressFirewall object defined, you must edit the existing policy to make changes to the egress firewall rules.

Prerequisites

  • A cluster that uses the OVN-Kubernetes network plugin.
  • Install the OpenShift CLI (oc).
  • You must log in to the cluster as a cluster administrator.

Procedure

  1. Create a policy rule:

    1. Create a <policy_name>.yaml file where <policy_name> describes the egress policy rules.
    2. In the file you created, define an egress policy object.

  2. Enter the following command to create the policy object. Replace <policy_name> with the name of the policy and <project> with the project that the rule applies to. 

    $ oc create -f <policy_name>.yaml -n <project>

    In the following example, a new EgressFirewall object is created in a project named project1: 

    $ oc create -f default.yaml -n project1

    Example output

    egressfirewall.k8s.ovn.org/v1 created

  3. Optional: Save the <policy_name>.yaml file so that you can make changes later.

7.6. Configuring IPsec encryption

By enabling IPsec, you can encrypt both internal pod-to-pod cluster traffic between nodes and external traffic between pods and IPsec endpoints external to your cluster. All pod-to-pod network traffic between nodes on the OVN-Kubernetes cluster network is encrypted with IPsec in Transport mode.

IPsec is disabled by default. You can enable IPsec either during or after installing the cluster. For information about cluster installation, see OpenShift Container Platform installation overview.

The following support limitations exist for IPsec on a OpenShift Container Platform cluster:

  • You must disable IPsec before updating to OpenShift Container Platform 4.15. There is a known issue that can cause interruptions in pod-to-pod communication if you update without disabling IPsec. (OCPBUGS-43323)
  • On IBM Cloud®, IPsec supports only NAT-T. Encapsulating Security Payload (ESP) is not supported on this platform.
  • If your cluster uses hosted control planes for Red Hat OpenShift Container Platform, IPsec is not supported for IPsec encryption of either pod-to-pod or traffic to external hosts.
  • Using ESP hardware offloading on any network interface is not supported if one or more of those interfaces is attached to Open vSwitch (OVS). Enabling IPsec for your cluster triggers the use of IPsec with interfaces attached to OVS. By default, OpenShift Container Platform disables ESP hardware offloading on any interfaces attached to OVS.
  • If you enabled IPsec for network interfaces that are not attached to OVS, a cluster administrator must manually disable ESP hardware offloading on each interface that is not attached to OVS.

The following list outlines key tasks in the IPsec documentation:

  • Enable and disable IPsec after cluster installation.
  • Configure IPsec encryption for traffic between the cluster and external hosts.
  • Verify that IPsec encrypts traffic between pods on different nodes.

7.6.1. Modes of operation

When using IPsec on your OpenShift Container Platform cluster, you can choose from the following operating modes:

Table 7.5. IPsec modes of operation
ModeDescriptionDefault

Disabled

No traffic is encrypted. This is the cluster default.

Yes

Full

Pod-to-pod traffic is encrypted as described in "Types of network traffic flows encrypted by pod-to-pod IPsec". Traffic to external nodes may be encrypted after you complete the required configuration steps for IPsec.

No

External

Traffic to external nodes may be encrypted after you complete the required configuration steps for IPsec.

No

7.6.2. Prerequisites

For IPsec support for encrypting traffic to external hosts, ensure that the following prerequisites are met:

  • The OVN-Kubernetes network plugin must be configured in local gateway mode, where ovnKubernetesConfig.gatewayConfig.routingViaHost=true.

  • The NMState Operator is installed. This Operator is required for specifying the IPsec configuration. For more information, see About the Kubernetes NMState Operator.

    Note

    The NMState Operator is supported on Google Cloud Platform (GCP) only for configuring IPsec.

  • The Butane tool (butane) is installed. To install Butane, see Installing Butane.

These prerequisites are required to add certificates into the host NSS database and to configure IPsec to communicate with external hosts.

7.6.3. Network connectivity requirements when IPsec is enabled

You must configure the network connectivity between machines to allow OpenShift Container Platform cluster components to communicate. Each machine must be able to resolve the hostnames of all other machines in the cluster.

Table 7.6. Ports used for all-machine to all-machine communications
ProtocolPortDescription

UDP

500

IPsec IKE packets

4500

IPsec NAT-T packets

ESP

N/A

IPsec Encapsulating Security Payload (ESP)

7.6.4. IPsec encryption for pod-to-pod traffic

For IPsec encryption of pod-to-pod traffic, the following sections describe which specific pod-to-pod traffic is encrypted, what kind of encryption protocol is used, and how X.509 certificates are handled. These sections do not apply to IPsec encryption between the cluster and external hosts, which you must configure manually for your specific external network infrastructure.

7.6.4.1. Types of network traffic flows encrypted by pod-to-pod IPsec

With IPsec enabled, only the following network traffic flows between pods are encrypted:

  • Traffic between pods on different nodes on the cluster network
  • Traffic from a pod on the host network to a pod on the cluster network

The following traffic flows are not encrypted:

  • Traffic between pods on the same node on the cluster network
  • Traffic between pods on the host network
  • Traffic from a pod on the cluster network to a pod on the host network

The encrypted and unencrypted flows are illustrated in the following diagram:

IPsec encrypted and unencrypted traffic flows

7.6.4.2. Encryption protocol and IPsec mode

The encrypt cipher used is AES-GCM-16-256. The integrity check value (ICV) is 16 bytes. The key length is 256 bits.

The IPsec mode used is Transport mode, a mode that encrypts end-to-end communication by adding an Encapsulated Security Payload (ESP) header to the IP header of the original packet and encrypts the packet data. OpenShift Container Platform does not currently use or support IPsec Tunnel mode for pod-to-pod communication.

7.6.4.3. Security certificate generation and rotation

The Cluster Network Operator (CNO) generates a self-signed X.509 certificate authority (CA) that is used by IPsec for encryption. Certificate signing requests (CSRs) from each node are automatically fulfilled by the CNO.

The CA is valid for 10 years. The individual node certificates are valid for 5 years and are automatically rotated after 4 1/2 years elapse.

7.6.5. IPsec encryption for external traffic

OpenShift Container Platform supports IPsec encryption for traffic to external hosts with TLS certificates that you must supply.

7.6.5.1. Supported platforms

This feature is supported on the following platforms:

  • Bare metal
  • Google Cloud Platform (GCP)
  • Red Hat OpenStack Platform (RHOSP)
  • VMware vSphere
Important

If you have Red Hat Enterprise Linux (RHEL) worker nodes, these do not support IPsec encryption for external traffic.

If your cluster uses hosted control planes for Red Hat OpenShift Container Platform, configuring IPsec for encrypting traffic to external hosts is not supported.

7.6.5.2. Limitations

Ensure that the following prohibitions are observed:

  • IPv6 configuration is not currently supported by the NMState Operator when configuring IPsec for external traffic.
  • Certificate common names (CN) in the provided certificate bundle must not begin with the ovs_ prefix, because this naming can conflict with pod-to-pod IPsec CN names in the Network Security Services (NSS) database of each node.

7.6.6. Enabling IPsec encryption

As a cluster administrator, you can enable pod-to-pod IPsec encryption and IPsec encryption between the cluster and external IPsec endpoints.

You can configure IPsec in either of the following modes:

  • Full: Encryption for pod-to-pod and external traffic
  • External: Encryption for external traffic

If you need to configure encryption for external traffic in addition to pod-to-pod traffic, you must also complete the "Configuring IPsec encryption for external traffic" procedure.

Prerequisites

  • Install the OpenShift CLI (oc).
  • You are logged in to the cluster as a user with cluster-admin privileges.
  • You have reduced the size of your cluster MTU by 46 bytes to allow for the overhead of the IPsec ESP header.

Procedure

  1. To enable IPsec encryption, enter the following command: 

    $ oc patch networks.operator.openshift.io cluster --type=merge \
-p '{
  "spec":{
    "defaultNetwork":{
      "ovnKubernetesConfig":{
        "ipsecConfig":{
          "mode":<mode>
        }}}}}'

    where:

    mode
    Specify External to encrypt only traffic to external hosts or specify Full to encrypt pod to pod traffic and optionally traffic to external hosts. By default, IPsec is disabled.
  2. Optional: If you need to encrypt traffic to external hosts, complete the "Configuring IPsec encryption for external traffic" procedure.

Verification

  1. To find the names of the OVN-Kubernetes data plane pods, enter the following command: 

    $ oc get pods -n openshift-ovn-kubernetes -l=app=ovnkube-node

    Example output

    ovnkube-node-5xqbf                       8/8     Running   0              28m
ovnkube-node-6mwcx                       8/8     Running   0              29m
ovnkube-node-ck5fr                       8/8     Running   0              31m
ovnkube-node-fr4ld                       8/8     Running   0              26m
ovnkube-node-wgs4l                       8/8     Running   0              33m
ovnkube-node-zfvcl                       8/8     Running   0              34m

  2. Verify that IPsec is enabled on your cluster by running the following command:

    Note

    As a cluster administrator, you can verify that IPsec is enabled between pods on your cluster when IPsec is configured in Full mode. This step does not verify whether IPsec is working between your cluster and external hosts. 

    $ oc -n openshift-ovn-kubernetes rsh ovnkube-node-<XXXXX> ovn-nbctl --no-leader-only get nb_global . ipsec

    where:

    <XXXXX>
    Specifies the random sequence of letters for a pod from the previous step.

    Example output

    true

7.6.7. Configuring IPsec encryption for external traffic

As a cluster administrator, to encrypt external traffic with IPsec you must configure IPsec for your network infrastructure, including providing PKCS#12 certificates. Because this procedure uses Butane to create machine configs, you must have the butane command installed.

Note

After you apply the machine config, the Machine Config Operator reboots affected nodes in your cluster to rollout the new machine config.

Prerequisites

  • Install the OpenShift CLI (oc).
  • You have installed the butane utility on your local computer.
  • You have installed the NMState Operator on the cluster.
  • You are logged in to the cluster as a user with cluster-admin privileges.
  • You have an existing PKCS#12 certificate for the IPsec endpoint and a CA cert in PEM format.
  • You enabled IPsec in either Full or External mode on your cluster.
  • The OVN-Kubernetes network plugin must be configured in local gateway mode, where ovnKubernetesConfig.gatewayConfig.routingViaHost=true.

Procedure

  1. Create an IPsec configuration with an NMState Operator node network configuration policy. For more information, see Libreswan as an IPsec VPN implementation.

    1. To identify the IP address of the cluster node that is the IPsec endpoint, enter the following command: 

      $ oc get nodes

    2. Create a file named ipsec-config.yaml that contains a node network configuration policy for the NMState Operator, such as in the following examples. For an overview about NodeNetworkConfigurationPolicy objects, see The Kubernetes NMState project.

      Example NMState IPsec transport configuration

      apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
  name: ipsec-config
spec:
  nodeSelector:
    kubernetes.io/hostname: "<hostname>" 1
  desiredState:
    interfaces:
    - name: <interface_name> 2
      type: ipsec
      libreswan:
        left: <cluster_node> 3
        leftid: '%fromcert'
        leftrsasigkey: '%cert'
        leftcert: left_server
        leftmodecfgclient: false
        right: <external_host> 4
        rightid: '%fromcert'
        rightrsasigkey: '%cert'
        rightsubnet: <external_address>/32 5
        ikev2: insist
        type: transport

      1
      Specifies the host name to apply the policy to. This host serves as the left side host in the IPsec configuration.
      2
      Specifies the name of the interface to create on the host.
      3
      Specifies the host name of the cluster node that terminates the IPsec tunnel on the cluster side. The name should match SAN [Subject Alternate Name] from your supplied PKCS#12 certificates.
      4
      Specifies the external host name, such as host.example.com. The name should match the SAN [Subject Alternate Name] from your supplied PKCS#12 certificates.
      5
      Specifies the IP address of the external host, such as 10.1.2.3/32.

      Example NMState IPsec tunnel configuration

      apiVersion: nmstate.io/v1
kind: NodeNetworkConfigurationPolicy
metadata:
  name: ipsec-config
spec:
  nodeSelector:
    kubernetes.io/hostname: "<hostname>" 1
  desiredState:
    interfaces:
    - name: <interface_name> 2
      type: ipsec
      libreswan:
        left: <cluster_node> 3
        leftid: '%fromcert'
        leftmodecfgclient: false
        leftrsasigkey: '%cert'
        leftcert: left_server
        right: <external_host> 4
        rightid: '%fromcert'
        rightrsasigkey: '%cert'
        rightsubnet: <external_address>/32 5
        ikev2: insist
        type: tunnel

      1
      Specifies the host name to apply the policy to. This host serves as the left side host in the IPsec configuration.
      2
      Specifies the name of the interface to create on the host.
      3
      Specifies the host name of the cluster node that terminates the IPsec tunnel on the cluster side. The name should match SAN [Subject Alternate Name] from your supplied PKCS#12 certificates.
      4
      Specifies the external host name, such as host.example.com. The name should match the SAN [Subject Alternate Name] from your supplied PKCS#12 certificates.
      5
      Specifies the IP address of the external host, such as 10.1.2.3/32.

    3. To configure the IPsec interface, enter the following command: 

      $ oc create -f ipsec-config.yaml

  2. Provide the following certificate files to add to the Network Security Services (NSS) database on each host. These files are imported as part of the Butane configuration in subsequent steps.

    • left_server.p12: The certificate bundle for the IPsec endpoints
    • ca.pem: The certificate authority that you signed your certificates with

  3. Create a machine config to add your certificates to the cluster:

    1. To create Butane config files for the control plane and worker nodes, enter the following command: 

      $ for role in master worker; do
  cat >> "99-ipsec-${role}-endpoint-config.bu" <<-EOF
  variant: openshift
  version: 4.16.0
  metadata:
    name: 99-${role}-import-certs
    labels:
      machineconfiguration.openshift.io/role: $role
  systemd:
    units:
    - name: ipsec-import.service
      enabled: true
      contents: |
        [Unit]
        Description=Import external certs into ipsec NSS
        Before=ipsec.service

        [Service]
        Type=oneshot
        ExecStart=/usr/local/bin/ipsec-addcert.sh
        RemainAfterExit=false
        StandardOutput=journal

        [Install]
        WantedBy=multi-user.target
  storage:
    files:
    - path: /etc/pki/certs/ca.pem
      mode: 0400
      overwrite: true
      contents:
        local: ca.pem
    - path: /etc/pki/certs/left_server.p12
      mode: 0400
      overwrite: true
      contents:
        local: left_server.p12
    - path: /usr/local/bin/ipsec-addcert.sh
      mode: 0740
      overwrite: true
      contents:
        inline: |
          #!/bin/bash -e
          echo "importing cert to NSS"
          certutil -A -n "CA" -t "CT,C,C" -d /var/lib/ipsec/nss/ -i /etc/pki/certs/ca.pem
          pk12util -W "" -i /etc/pki/certs/left_server.p12 -d /var/lib/ipsec/nss/
          certutil -M -n "left_server" -t "u,u,u" -d /var/lib/ipsec/nss/
EOF
done

    2. To transform the Butane files that you created in the previous step into machine configs, enter the following command: 

      $ for role in master worker; do
  butane -d . 99-ipsec-${role}-endpoint-config.bu -o ./99-ipsec-$role-endpoint-config.yaml
done

  4. To apply the machine configs to your cluster, enter the following command: 

    $ for role in master worker; do
  oc apply -f 99-ipsec-${role}-endpoint-config.yaml
done
    Important

    As the Machine Config Operator (MCO) updates machines in each machine config pool, it reboots each node one by one. You must wait until all the nodes are updated before external IPsec connectivity is available.

  5. Check the machine config pool status by entering the following command: 

    $ oc get mcp

    A successfully updated node has the following status: UPDATED=true, UPDATING=false, DEGRADED=false.

    Note

    By default, the MCO updates one machine per pool at a time, causing the total time the migration takes to increase with the size of the cluster.

  6. To confirm that IPsec machine configs rolled out successfully, enter the following commands:

    1. Confirm that the IPsec machine configs were created: 

      $ oc get mc | grep ipsec

      Example output

      80-ipsec-master-extensions        3.2.0        6d15h
80-ipsec-worker-extensions        3.2.0        6d15h

    2. Confirm that the that the IPsec extension are applied to control plane nodes: 

      $ oc get mcp master -o yaml | grep 80-ipsec-master-extensions -c

      Expected output

      2

    3. Confirm that the that the IPsec extension are applied to worker nodes: 

      $ oc get mcp worker -o yaml | grep 80-ipsec-worker-extensions -c

      Expected output

      2

Additional resources

7.6.8. Disabling IPsec encryption for an external IPsec endpoint

As a cluster administrator, you can remove an existing IPsec tunnel to an external host.

Prerequisites

  • Install the OpenShift CLI (oc).
  • You are logged in to the cluster as a user with cluster-admin privileges.
  • You enabled IPsec in either Full or External mode on your cluster.

Procedure

  1. Create a file named remove-ipsec-tunnel.yaml with the following YAML: 

    kind: NodeNetworkConfigurationPolicy
apiVersion: nmstate.io/v1
metadata:
  name: <name>
spec:
  nodeSelector:
    kubernetes.io/hostname: <node_name>
  desiredState:
    interfaces:
    - name: <tunnel_name>
      type: ipsec
      state: absent

    where:

    name
    Specifies a name for the node network configuration policy.
    node_name
    Specifies the name of the node where the IPsec tunnel that you want to remove exists.
    tunnel_name
    Specifies the interface name for the existing IPsec tunnel.

  2. To remove the IPsec tunnel, enter the following command: 

    $ oc apply -f remove-ipsec-tunnel.yaml

7.6.9. Disabling IPsec encryption

As a cluster administrator, you can disable IPsec encryption.

Prerequisites

  • Install the OpenShift CLI (oc).
  • Log in to the cluster with a user with cluster-admin privileges.

Procedure

  1. To disable IPsec encryption, enter the following command: 

    $ oc patch networks.operator.openshift.io cluster --type=merge \
-p '{
  "spec":{
    "defaultNetwork":{
      "ovnKubernetesConfig":{
        "ipsecConfig":{
          "mode":"Disabled"
        }}}}}'
  2. Optional: You can increase the size of your cluster MTU by 46 bytes because there is no longer any overhead from the IPsec ESP header in IP packets.

7.6.10. Additional resources

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