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Chapter 22. Configuring ingress cluster traffic
22.1. Configuring ingress cluster traffic overview
OpenShift Container Platform provides the following methods for communicating from outside the cluster with services running in the cluster.
The methods are recommended, in order or preference:
- If you have HTTP/HTTPS, use an Ingress Controller.
- If you have a TLS-encrypted protocol other than HTTPS. For example, for TLS with the SNI header, use an Ingress Controller.
-
Otherwise, use a Load Balancer, an External IP, or a
NodePort
.
Method | Purpose |
---|---|
Allows access to HTTP/HTTPS traffic and TLS-encrypted protocols other than HTTPS (for example, TLS with the SNI header). | |
Automatically assign an external IP using a load balancer service | Allows traffic to non-standard ports through an IP address assigned from a pool. Most cloud platforms offer a method to start a service with a load-balancer IP address. |
Allows traffic to a specific IP address or address from a pool on the machine network. For bare-metal installations or platforms that are like bare metal, MetalLB provides a way to start a service with a load-balancer IP address. | |
Allows traffic to non-standard ports through a specific IP address. | |
Expose a service on all nodes in the cluster. |
22.1.1. Comparision: Fault tolerant access to external IP addresses
For the communication methods that provide access to an external IP address, fault tolerant access to the IP address is another consideration. The following features provide fault tolerant access to an external IP address.
- IP failover
- IP failover manages a pool of virtual IP address for a set of nodes. It is implemented with Keepalived and Virtual Router Redundancy Protocol (VRRP). IP failover is a layer 2 mechanism only and relies on multicast. Multicast can have disadvantages for some networks.
- MetalLB
- MetalLB has a layer 2 mode, but it does not use multicast. Layer 2 mode has a disadvantage that it transfers all traffic for an external IP address through one node.
- Manually assigning external IP addresses
- You can configure your cluster with an IP address block that is used to assign external IP addresses to services. By default, this feature is disabled. This feature is flexible, but places the largest burden on the cluster or network administrator. The cluster is prepared to receive traffic that is destined for the external IP, but each customer has to decide how they want to route traffic to nodes.
22.2. Configuring ExternalIPs for services
As a cluster administrator, you can designate an IP address block that is external to the cluster that can send traffic to services in the cluster.
This functionality is generally most useful for clusters installed on bare-metal hardware.
22.2.1. Prerequisites
- Your network infrastructure must route traffic for the external IP addresses to your cluster.
22.2.2. About ExternalIP
For non-cloud environments, OpenShift Container Platform supports the assignment of external IP addresses to a Service
object spec.externalIPs[]
field through the ExternalIP facility. By setting this field, OpenShift Container Platform assigns an additional virtual IP address to the service. The IP address can be outside the service network defined for the cluster. A service configured with an ExternalIP functions similarly to a service with type=NodePort
, allowing you to direct traffic to a local node for load balancing.
You must configure your networking infrastructure to ensure that the external IP address blocks that you define are routed to the cluster. As a result, the IP address is not configured in the network interfaces from nodes. To handle the traffic, you must configure the routing and access to the external IP by using a method such as static Address Resolution Protocol (ARP) entries.
OpenShift Container Platform extends the ExternalIP functionality in Kubernetes by adding the following capabilities:
- Restrictions on the use of external IP addresses by users through a configurable policy
- Allocation of an external IP address automatically to a service upon request
Disabled by default, use of ExternalIP functionality can be a security risk, because in-cluster traffic to an external IP address is directed to that service. This could allow cluster users to intercept sensitive traffic destined for external resources.
This feature is supported only in non-cloud deployments. For cloud deployments, use the load balancer services for automatic deployment of a cloud load balancer to target the endpoints of a service.
You can use either a MetalLB implementation or an IP failover deployment to attach an ExternalIP resource to a service in the following ways:
- Automatic assignment of an external IP
-
OpenShift Container Platform automatically assigns an IP address from the
autoAssignCIDRs
CIDR block to thespec.externalIPs[]
array when you create aService
object withspec.type=LoadBalancer
set. In this case, OpenShift Container Platform implements a non-cloud version of the load balancer service type and assigns IP addresses to the services. Automatic assignment is disabled by default and must be configured by a cluster administrator as described in the following section. - Manual assignment of an external IP
-
OpenShift Container Platform uses the IP addresses assigned to the
spec.externalIPs[]
array when you create aService
object. You cannot specify an IP address that is already in use by another service.
22.2.2.1. Configuration for ExternalIP
Use of an external IP address in OpenShift Container Platform is governed by the following fields in the Network.config.openshift.io
CR named cluster
:
-
spec.externalIP.autoAssignCIDRs
defines an IP address block used by the load balancer when choosing an external IP address for the service. OpenShift Container Platform supports only a single IP address block for automatic assignment. This can be simpler than having to manage the port space of a limited number of shared IP addresses when manually assigning ExternalIPs to services. If automatic assignment is enabled, aService
object withspec.type=LoadBalancer
is allocated an external IP address. -
spec.externalIP.policy
defines the permissible IP address blocks when manually specifying an IP address. OpenShift Container Platform does not apply policy rules to IP address blocks defined byspec.externalIP.autoAssignCIDRs
.
If routed correctly, external traffic from the configured external IP address block can reach service endpoints through any TCP or UDP port that the service exposes.
As a cluster administrator, you must configure routing to externalIPs. You must also ensure that the IP address block you assign terminates at one or more nodes in your cluster. For more information, see Kubernetes External IPs.
OpenShift Container Platform supports both the automatic and manual assignment of IP addresses, and each address is guaranteed to be assigned to a maximum of one service. This ensures that each service can expose its chosen ports regardless of the ports exposed by other services.
To use IP address blocks defined by autoAssignCIDRs
in OpenShift Container Platform, you must configure the necessary IP address assignment and routing for your host network.
The following YAML describes a service with an external IP address configured:
Example Service
object with spec.externalIPs[]
set
apiVersion: v1 kind: Service metadata: name: http-service spec: clusterIP: 172.30.163.110 externalIPs: - 192.168.132.253 externalTrafficPolicy: Cluster ports: - name: highport nodePort: 31903 port: 30102 protocol: TCP targetPort: 30102 selector: app: web sessionAffinity: None type: LoadBalancer status: loadBalancer: ingress: - ip: 192.168.132.253
22.2.2.2. Restrictions on the assignment of an external IP address
As a cluster administrator, you can specify IP address blocks to allow and to reject.
Restrictions apply only to users without cluster-admin
privileges. A cluster administrator can always set the service spec.externalIPs[]
field to any IP address.
You configure IP address policy with a policy
object defined by specifying the spec.ExternalIP.policy
field. The policy object has the following shape:
{ "policy": { "allowedCIDRs": [], "rejectedCIDRs": [] } }
When configuring policy restrictions, the following rules apply:
-
If
policy={}
is set, then creating aService
object withspec.ExternalIPs[]
set will fail. This is the default for OpenShift Container Platform. The behavior whenpolicy=null
is set is identical. If
policy
is set and eitherpolicy.allowedCIDRs[]
orpolicy.rejectedCIDRs[]
is set, the following rules apply:-
If
allowedCIDRs[]
andrejectedCIDRs[]
are both set, thenrejectedCIDRs[]
has precedence overallowedCIDRs[]
. -
If
allowedCIDRs[]
is set, creating aService
object withspec.ExternalIPs[]
will succeed only if the specified IP addresses are allowed. -
If
rejectedCIDRs[]
is set, creating aService
object withspec.ExternalIPs[]
will succeed only if the specified IP addresses are not rejected.
-
If
22.2.2.3. Example policy objects
The examples that follow demonstrate several different policy configurations.
In the following example, the policy prevents OpenShift Container Platform from creating any service with an external IP address specified:
Example policy to reject any value specified for
Service
objectspec.externalIPs[]
apiVersion: config.openshift.io/v1 kind: Network metadata: name: cluster spec: externalIP: policy: {} ...
In the following example, both the
allowedCIDRs
andrejectedCIDRs
fields are set.Example policy that includes both allowed and rejected CIDR blocks
apiVersion: config.openshift.io/v1 kind: Network metadata: name: cluster spec: externalIP: policy: allowedCIDRs: - 172.16.66.10/23 rejectedCIDRs: - 172.16.66.10/24 ...
In the following example,
policy
is set tonull
. If set tonull
, when inspecting the configuration object by enteringoc get networks.config.openshift.io -o yaml
, thepolicy
field will not appear in the output.Example policy to allow any value specified for
Service
objectspec.externalIPs[]
apiVersion: config.openshift.io/v1 kind: Network metadata: name: cluster spec: externalIP: policy: null ...
22.2.3. ExternalIP address block configuration
The configuration for ExternalIP address blocks is defined by a Network custom resource (CR) named cluster
. The Network CR is part of the config.openshift.io
API group.
During cluster installation, the Cluster Version Operator (CVO) automatically creates a Network CR named cluster
. Creating any other CR objects of this type is not supported.
The following YAML describes the ExternalIP configuration:
Network.config.openshift.io CR named cluster
apiVersion: config.openshift.io/v1 kind: Network metadata: name: cluster spec: externalIP: autoAssignCIDRs: [] 1 policy: 2 ...
- 1
- Defines the IP address block in CIDR format that is available for automatic assignment of external IP addresses to a service. Only a single IP address range is allowed.
- 2
- Defines restrictions on manual assignment of an IP address to a service. If no restrictions are defined, specifying the
spec.externalIP
field in aService
object is not allowed. By default, no restrictions are defined.
The following YAML describes the fields for the policy
stanza:
Network.config.openshift.io policy
stanza
policy: allowedCIDRs: [] 1 rejectedCIDRs: [] 2
Example external IP configurations
Several possible configurations for external IP address pools are displayed in the following examples:
The following YAML describes a configuration that enables automatically assigned external IP addresses:
Example configuration with
spec.externalIP.autoAssignCIDRs
setapiVersion: config.openshift.io/v1 kind: Network metadata: name: cluster spec: ... externalIP: autoAssignCIDRs: - 192.168.132.254/29
The following YAML configures policy rules for the allowed and rejected CIDR ranges:
Example configuration with
spec.externalIP.policy
setapiVersion: config.openshift.io/v1 kind: Network metadata: name: cluster spec: ... externalIP: policy: allowedCIDRs: - 192.168.132.0/29 - 192.168.132.8/29 rejectedCIDRs: - 192.168.132.7/32
22.2.4. Configure external IP address blocks for your cluster
As a cluster administrator, you can configure the following ExternalIP settings:
-
An ExternalIP address block used by OpenShift Container Platform to automatically populate the
spec.clusterIP
field for aService
object. -
A policy object to restrict what IP addresses may be manually assigned to the
spec.clusterIP
array of aService
object.
Prerequisites
-
Install the OpenShift CLI (
oc
). -
Access to the cluster as a user with the
cluster-admin
role.
Procedure
Optional: To display the current external IP configuration, enter the following command:
$ oc describe networks.config cluster
To edit the configuration, enter the following command:
$ oc edit networks.config cluster
Modify the ExternalIP configuration, as in the following example:
apiVersion: config.openshift.io/v1 kind: Network metadata: name: cluster spec: ... externalIP: 1 ...
- 1
- Specify the configuration for the
externalIP
stanza.
To confirm the updated ExternalIP configuration, enter the following command:
$ oc get networks.config cluster -o go-template='{{.spec.externalIP}}{{"\n"}}'
22.2.5. Next steps
22.3. Configuring ingress cluster traffic using an Ingress Controller
OpenShift Container Platform provides methods for communicating from outside the cluster with services running in the cluster. This method uses an Ingress Controller.
22.3.1. Using Ingress Controllers and routes
The Ingress Operator manages Ingress Controllers and wildcard DNS.
Using an Ingress Controller is the most common way to allow external access to an OpenShift Container Platform cluster.
An Ingress Controller is configured to accept external requests and proxy them based on the configured routes. This is limited to HTTP, HTTPS using SNI, and TLS using SNI, which is sufficient for web applications and services that work over TLS with SNI.
Work with your administrator to configure an Ingress Controller to accept external requests and proxy them based on the configured routes.
The administrator can create a wildcard DNS entry and then set up an Ingress Controller. Then, you can work with the edge Ingress Controller without having to contact the administrators.
By default, every Ingress Controller in the cluster can admit any route created in any project in the cluster.
The Ingress Controller:
- Has two replicas by default, which means it should be running on two worker nodes.
- Can be scaled up to have more replicas on more nodes.
The procedures in this section require prerequisites performed by the cluster administrator.
22.3.2. Prerequisites
Before starting the following procedures, the administrator must:
- Set up the external port to the cluster networking environment so that requests can reach the cluster.
Make sure there is at least one user with cluster admin role. To add this role to a user, run the following command:
$ oc adm policy add-cluster-role-to-user cluster-admin username
- You have an OpenShift Container Platform cluster with at least one master and at least one node and a system outside the cluster that has network access to the cluster. This procedure assumes that the external system is on the same subnet as the cluster. The additional networking required for external systems on a different subnet is out-of-scope for this topic.
22.3.3. Creating a project and service
If the project and service that you want to expose does not exist, create the project and then create the service.
If the project and service already exists, skip to the procedure on exposing the service to create a route.
Prerequisites
-
Install the OpenShift CLI (
oc
) and log in as a cluster administrator.
Procedure
Create a new project for your service by running the
oc new-project
command:$ oc new-project <project_name>
Use the
oc new-app
command to create your service:$ oc new-app nodejs:12~https://github.com/sclorg/nodejs-ex.git
To verify that the service was created, run the following command:
$ oc get svc -n <project_name>
Example output
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE nodejs-ex ClusterIP 172.30.197.157 <none> 8080/TCP 70s
NoteBy default, the new service does not have an external IP address.
22.3.4. Exposing the service by creating a route
You can expose the service as a route by using the oc expose
command.
Prerequisites
- You logged into OpenShift Container Platform.
Procedure
Log in to the project where the service you want to expose is located:
$ oc project <project_name>
Run the
oc expose service
command to expose the route:$ oc expose service nodejs-ex
Example output
route.route.openshift.io/nodejs-ex exposed
To verify that the service is exposed, you can use a tool, such as
curl
to check that the service is accessible from outside the cluster.To find the hostname of the route, enter the following command:
$ oc get route
Example output
NAME HOST/PORT PATH SERVICES PORT TERMINATION WILDCARD nodejs-ex nodejs-ex-myproject.example.com nodejs-ex 8080-tcp None
To check that the host responds to a GET request, enter the following command:
Example
curl
command$ curl --head nodejs-ex-myproject.example.com
Example output
HTTP/1.1 200 OK ...
22.3.5. Ingress sharding in OpenShift Container Platform
In OpenShift Container Platform, an Ingress Controller can serve all routes, or it can serve a subset of routes. By default, the Ingress Controller serves any route created in any namespace in the cluster. You can add additional Ingress Controllers to your cluster to optimize routing by creating shards, which are subsets of routes based on selected characteristics. To mark a route as a member of a shard, use labels in the route or namespace metadata
field. The Ingress Controller uses selectors, also known as a selection expression, to select a subset of routes from the entire pool of routes to serve.
Ingress sharding is useful in cases where you want to load balance incoming traffic across multiple Ingress Controllers, when you want to isolate traffic to be routed to a specific Ingress Controller, or for a variety of other reasons described in the next section.
By default, each route uses the default domain of the cluster. However, routes can be configured to use the domain of the router instead.
22.3.6. Ingress Controller sharding
You can use Ingress sharding, also known as router sharding, to distribute a set of routes across multiple routers by adding labels to routes, namespaces, or both. The Ingress Controller uses a corresponding set of selectors to admit only the routes that have a specified label. Each Ingress shard comprises the routes that are filtered using a given selection expression.
As the primary mechanism for traffic to enter the cluster, the demands on the Ingress Controller can be significant. As a cluster administrator, you can shard the routes to:
- Balance Ingress Controllers, or routers, with several routes to speed up responses to changes.
- Allocate certain routes to have different reliability guarantees than other routes.
- Allow certain Ingress Controllers to have different policies defined.
- Allow only specific routes to use additional features.
- Expose different routes on different addresses so that internal and external users can see different routes, for example.
- Transfer traffic from one version of an application to another during a blue green deployment.
When Ingress Controllers are sharded, a given route is admitted to zero or more Ingress Controllers in the group. A route’s status describes whether an Ingress Controller has admitted it or not. An Ingress Controller will only admit a route if it is unique to its shard.
An Ingress Controller can use three sharding methods:
- Adding only a namespace selector to the Ingress Controller, so that all routes in a namespace with labels that match the namespace selector are in the Ingress shard.
- Adding only a route selector to the Ingress Controller, so that all routes with labels that match the route selector are in the Ingress shard.
- Adding both a namespace selector and route selector to the Ingress Controller, so that routes with labels that match the route selector in a namespace with labels that match the namespace selector are in the Ingress shard.
With sharding, you can distribute subsets of routes over multiple Ingress Controllers. These subsets can be non-overlapping, also called traditional sharding, or overlapping, otherwise known as overlapped sharding.
22.3.6.1. Traditional sharding example
An example of a configured Ingress Controller finops-router
that has the label selector spec.namespaceSelector.matchExpressions
with key values set to finance
and ops
:
Example YAML definition for finops-router
apiVersion: operator.openshift.io/v1 kind: IngressController metadata: name: finops-router namespace: openshift-ingress-operator spec: namespaceSelector: matchExpressions: - key: name operator: In values: - finance - ops
An example of a configured Ingress Controller dev-router
that has the label selector spec.namespaceSelector.matchLabels.name
with the key value set to dev
:
Example YAML definition for dev-router
apiVersion: operator.openshift.io/v1 kind: IngressController metadata: name: dev-router namespace: openshift-ingress-operator spec: namespaceSelector: matchLabels: name: dev
If all application routes are in separate namespaces, such as each labeled with name:finance
, name:ops
, and name:dev
, the configuration effectively distributes your routes between the two Ingress Controllers. OpenShift Container Platform routes for console, authentication, and other purposes should not be handled.
In the previous scenario, sharding becomes a special case of partitioning, with no overlapping subsets. Routes are divided between router shards.
The default
Ingress Controller continues to serve all routes unless the namespaceSelector
or routeSelector
fields contain routes that are meant for exclusion. See this Red Hat Knowledgebase solution and the section "Sharding the default Ingress Controller" for more information on how to exclude routes from the default Ingress Controller.
22.3.6.2. Overlapped sharding example
An example of a configured Ingress Controller devops-router
that has the label selector spec.namespaceSelector.matchExpressions
with key values set to dev
and ops
:
Example YAML definition for devops-router
apiVersion: operator.openshift.io/v1 kind: IngressController metadata: name: devops-router namespace: openshift-ingress-operator spec: namespaceSelector: matchExpressions: - key: name operator: In values: - dev - ops
The routes in the namespaces labeled name:dev
and name:ops
are now serviced by two different Ingress Controllers. With this configuration, you have overlapping subsets of routes.
With overlapping subsets of routes you can create more complex routing rules. For example, you can divert higher priority traffic to the dedicated finops-router
while sending lower priority traffic to devops-router
.
22.3.6.3. Sharding the default Ingress Controller
After creating a new Ingress shard, there might be routes that are admitted to your new Ingress shard that are also admitted by the default Ingress Controller. This is because the default Ingress Controller has no selectors and admits all routes by default.
You can restrict an Ingress Controller from servicing routes with specific labels using either namespace selectors or route selectors. The following procedure restricts the default Ingress Controller from servicing your newly sharded finance
, ops
, and dev
, routes using a namespace selector. This adds further isolation to Ingress shards.
You must keep all of OpenShift Container Platform’s administration routes on the same Ingress Controller. Therefore, avoid adding additional selectors to the default Ingress Controller that exclude these essential routes.
Prerequisites
-
You installed the OpenShift CLI (
oc
). - You are logged in as a project administrator.
Procedure
Modify the default Ingress Controller by running the following command:
$ oc edit ingresscontroller -n openshift-ingress-operator default
Edit the Ingress Controller to contain a
namespaceSelector
that excludes the routes with any of thefinance
,ops
, anddev
labels:apiVersion: operator.openshift.io/v1 kind: IngressController metadata: name: default namespace: openshift-ingress-operator spec: namespaceSelector: matchExpressions: - key: name operator: NotIn values: - finance - ops - dev
The default Ingress Controller will no longer serve the namespaces labeled name:finance
, name:ops
, and name:dev
.
22.3.6.4. Ingress sharding and DNS
The cluster administrator is responsible for making a separate DNS entry for each router in a project. A router will not forward unknown routes to another router.
Consider the following example:
-
Router A lives on host 192.168.0.5 and has routes with
*.foo.com
. -
Router B lives on host 192.168.1.9 and has routes with
*.example.com
.
Separate DNS entries must resolve *.foo.com
to the node hosting Router A and *.example.com
to the node hosting Router B:
-
*.foo.com A IN 192.168.0.5
-
*.example.com A IN 192.168.1.9
22.3.6.5. Configuring Ingress Controller sharding by using route labels
Ingress Controller sharding by using route labels means that the Ingress Controller serves any route in any namespace that is selected by the route selector.
Figure 22.1. Ingress sharding using route labels
Ingress Controller sharding is useful when balancing incoming traffic load among a set of Ingress Controllers and when isolating traffic to a specific Ingress Controller. For example, company A goes to one Ingress Controller and company B to another.
Procedure
Edit the
router-internal.yaml
file:apiVersion: operator.openshift.io/v1 kind: IngressController metadata: name: sharded namespace: openshift-ingress-operator spec: domain: <apps-sharded.basedomain.example.net> 1 nodePlacement: nodeSelector: matchLabels: node-role.kubernetes.io/worker: "" routeSelector: matchLabels: type: sharded
- 1
- Specify a domain to be used by the Ingress Controller. This domain must be different from the default Ingress Controller domain.
Apply the Ingress Controller
router-internal.yaml
file:# oc apply -f router-internal.yaml
The Ingress Controller selects routes in any namespace that have the label
type: sharded
.Create a new route using the domain configured in the
router-internal.yaml
:$ oc expose svc <service-name> --hostname <route-name>.apps-sharded.basedomain.example.net
22.3.6.6. Configuring Ingress Controller sharding by using namespace labels
Ingress Controller sharding by using namespace labels means that the Ingress Controller serves any route in any namespace that is selected by the namespace selector.
Figure 22.2. Ingress sharding using namespace labels
Ingress Controller sharding is useful when balancing incoming traffic load among a set of Ingress Controllers and when isolating traffic to a specific Ingress Controller. For example, company A goes to one Ingress Controller and company B to another.
Procedure
Edit the
router-internal.yaml
file:$ cat router-internal.yaml
Example output
apiVersion: operator.openshift.io/v1 kind: IngressController metadata: name: sharded namespace: openshift-ingress-operator spec: domain: <apps-sharded.basedomain.example.net> 1 nodePlacement: nodeSelector: matchLabels: node-role.kubernetes.io/worker: "" namespaceSelector: matchLabels: type: sharded
- 1
- Specify a domain to be used by the Ingress Controller. This domain must be different from the default Ingress Controller domain.
Apply the Ingress Controller
router-internal.yaml
file:$ oc apply -f router-internal.yaml
The Ingress Controller selects routes in any namespace that is selected by the namespace selector that have the label
type: sharded
.Create a new route using the domain configured in the
router-internal.yaml
:$ oc expose svc <service-name> --hostname <route-name>.apps-sharded.basedomain.example.net
22.3.6.7. Creating a route for Ingress Controller sharding
A route allows you to host your application at a URL. In this case, the hostname is not set and the route uses a subdomain instead. When you specify a subdomain, you automatically use the domain of the Ingress Controller that exposes the route. For situations where a route is exposed by multiple Ingress Controllers, the route is hosted at multiple URLs.
The following procedure describes how to create a route for Ingress Controller sharding, using the hello-openshift
application as an example.
Ingress Controller sharding is useful when balancing incoming traffic load among a set of Ingress Controllers and when isolating traffic to a specific Ingress Controller. For example, company A goes to one Ingress Controller and company B to another.
Prerequisites
-
You installed the OpenShift CLI (
oc
). - You are logged in as a project administrator.
- You have a web application that exposes a port and an HTTP or TLS endpoint listening for traffic on the port.
- You have configured the Ingress Controller for sharding.
Procedure
Create a project called
hello-openshift
by running the following command:$ oc new-project hello-openshift
Create a pod in the project by running the following command:
$ oc create -f https://raw.githubusercontent.com/openshift/origin/master/examples/hello-openshift/hello-pod.json
Create a service called
hello-openshift
by running the following command:$ oc expose pod/hello-openshift
Create a route definition called
hello-openshift-route.yaml
:YAML definition of the created route for sharding
apiVersion: route.openshift.io/v1 kind: Route metadata: labels: type: sharded 1 name: hello-openshift-edge namespace: hello-openshift spec: subdomain: hello-openshift 2 tls: termination: edge to: kind: Service name: hello-openshift
- 1
- Both the label key and its corresponding label value must match the ones specified in the Ingress Controller. In this example, the Ingress Controller has the label key and value
type: sharded
. - 2
- The route will be exposed using the value of the
subdomain
field. When you specify thesubdomain
field, you must leave the hostname unset. If you specify both thehost
andsubdomain
fields, then the route will use the value of thehost
field, and ignore thesubdomain
field.
Use
hello-openshift-route.yaml
to create a route to thehello-openshift
application by running the following command:$ oc -n hello-openshift create -f hello-openshift-route.yaml
Verification
Get the status of the route with the following command:
$ oc -n hello-openshift get routes/hello-openshift-edge -o yaml
The resulting
Route
resource should look similar to the following:Example output
apiVersion: route.openshift.io/v1 kind: Route metadata: labels: type: sharded name: hello-openshift-edge namespace: hello-openshift spec: subdomain: hello-openshift tls: termination: edge to: kind: Service name: hello-openshift status: ingress: - host: hello-openshift.<apps-sharded.basedomain.example.net> 1 routerCanonicalHostname: router-sharded.<apps-sharded.basedomain.example.net> 2 routerName: sharded 3
- 1
- The hostname the Ingress Controller, or router, uses to expose the route. The value of the
host
field is automatically determined by the Ingress Controller, and uses its domain. In this example, the domain of the Ingress Controller is<apps-sharded.basedomain.example.net>
. - 2
- The hostname of the Ingress Controller.
- 3
- The name of the Ingress Controller. In this example, the Ingress Controller has the name
sharded
.
Additional resources
22.4. Configuring the Ingress Controller endpoint publishing strategy
The endpointPublishingStrategy
is used to publish the Ingress Controller endpoints to other networks, enable load balancer integrations, and provide access to other systems.
On Red Hat OpenStack Platform (RHOSP), the LoadBalancerService
endpoint publishing strategy is supported only if a cloud provider is configured to create health monitors. For RHOSP 16.2, this strategy is possible only if you use the Amphora Octavia provider.
For more information, see the "Setting RHOSP Cloud Controller Manager options" section of the RHOSP installation documentation.
22.4.1. Ingress Controller endpoint publishing strategy
NodePortService
endpoint publishing strategy
The NodePortService
endpoint publishing strategy publishes the Ingress Controller using a Kubernetes NodePort service.
In this configuration, the Ingress Controller deployment uses container networking. A NodePortService
is created to publish the deployment. The specific node ports are dynamically allocated by OpenShift Container Platform; however, to support static port allocations, your changes to the node port field of the managed NodePortService
are preserved.
Figure 22.3. Diagram of NodePortService
The preceding graphic shows the following concepts pertaining to OpenShift Container Platform Ingress NodePort endpoint publishing strategy:
- All the available nodes in the cluster have their own, externally accessible IP addresses. The service running in the cluster is bound to the unique NodePort for all the nodes.
-
When the client connects to a node that is down, for example, by connecting the
10.0.128.4
IP address in the graphic, the node port directly connects the client to an available node that is running the service. In this scenario, no load balancing is required. As the image shows, the10.0.128.4
address is down and another IP address must be used instead.
The Ingress Operator ignores any updates to .spec.ports[].nodePort
fields of the service.
By default, ports are allocated automatically and you can access the port allocations for integrations. However, sometimes static port allocations are necessary to integrate with existing infrastructure which may not be easily reconfigured in response to dynamic ports. To achieve integrations with static node ports, you can update the managed service resource directly.
For more information, see the Kubernetes Services documentation on NodePort
.
HostNetwork
endpoint publishing strategy
The HostNetwork
endpoint publishing strategy publishes the Ingress Controller on node ports where the Ingress Controller is deployed.
An Ingress Controller with the HostNetwork
endpoint publishing strategy can have only one pod replica per node. If you want n replicas, you must use at least n nodes where those replicas can be scheduled. Because each pod replica requests ports 80
and 443
on the node host where it is scheduled, a replica cannot be scheduled to a node if another pod on the same node is using those ports.
The HostNetwork
object has a hostNetwork
field with the following default values for the optional binding ports: httpPort: 80
, httpsPort: 443
, and statsPort: 1936
. By specifying different binding ports for your network, you can deploy multiple Ingress Controllers on the same node for the HostNetwork
strategy.
Example
apiVersion: operator.openshift.io/v1 kind: IngressController metadata: name: internal namespace: openshift-ingress-operator spec: domain: example.com endpointPublishingStrategy: type: HostNetwork hostNetwork: httpPort: 80 httpsPort: 443 statsPort: 1936
22.4.1.1. Configuring the Ingress Controller endpoint publishing scope to Internal
When a cluster administrator installs a new cluster without specifying that the cluster is private, the default Ingress Controller is created with a scope
set to External
. Cluster administrators can change an External
scoped Ingress Controller to Internal
.
Prerequisites
-
You installed the
oc
CLI.
Procedure
To change an
External
scoped Ingress Controller toInternal
, enter the following command:$ oc -n openshift-ingress-operator patch ingresscontrollers/default --type=merge --patch='{"spec":{"endpointPublishingStrategy":{"type":"LoadBalancerService","loadBalancer":{"scope":"Internal"}}}}'
To check the status of the Ingress Controller, enter the following command:
$ oc -n openshift-ingress-operator get ingresscontrollers/default -o yaml
The
Progressing
status condition indicates whether you must take further action. For example, the status condition can indicate that you need to delete the service by entering the following command:$ oc -n openshift-ingress delete services/router-default
If you delete the service, the Ingress Operator recreates it as
Internal
.
22.4.1.2. Configuring the Ingress Controller endpoint publishing scope to External
When a cluster administrator installs a new cluster without specifying that the cluster is private, the default Ingress Controller is created with a scope
set to External
.
The Ingress Controller’s scope can be configured to be Internal
during installation or after, and cluster administrators can change an Internal
Ingress Controller to External
.
On some platforms, it is necessary to delete and recreate the service.
Changing the scope can cause disruption to Ingress traffic, potentially for several minutes. This applies to platforms where it is necessary to delete and recreate the service, because the procedure can cause OpenShift Container Platform to deprovision the existing service load balancer, provision a new one, and update DNS.
Prerequisites
-
You installed the
oc
CLI.
Procedure
To change an
Internal
scoped Ingress Controller toExternal
, enter the following command:$ oc -n openshift-ingress-operator patch ingresscontrollers/private --type=merge --patch='{"spec":{"endpointPublishingStrategy":{"type":"LoadBalancerService","loadBalancer":{"scope":"External"}}}}'
To check the status of the Ingress Controller, enter the following command:
$ oc -n openshift-ingress-operator get ingresscontrollers/default -o yaml
The
Progressing
status condition indicates whether you must take further action. For example, the status condition can indicate that you need to delete the service by entering the following command:$ oc -n openshift-ingress delete services/router-default
If you delete the service, the Ingress Operator recreates it as
External
.
22.4.1.3. Adding a single NodePort service to an Ingress Controller
Instead of creating a NodePort
-type Service
for each project, you can create a custom Ingress Controller to use the NodePortService
endpoint publishing strategy. To prevent port conflicts, consider this configuration for your Ingress Controller when you want to apply a set of routes, through Ingress sharding, to nodes that might already have a HostNetwork
Ingress Controller.
Before you set a NodePort
-type Service
for each project, read the following considerations:
- You must create a wildcard DNS record for the Nodeport Ingress Controller domain. A Nodeport Ingress Controller route can be reached from the address of a worker node. For more information about the required DNS records for routes, see "User-provisioned DNS requirements".
-
You must expose a route for your service and specify the
--hostname
argument for your custom Ingress Controller domain. -
You must append the port that is assigned to the
NodePort
-typeService
in the route so that you can access application pods.
Prerequisites
-
You installed the OpenShift CLI (
oc
). -
Logged in as a user with
cluster-admin
privileges. - You created a wildcard DNS record.
Procedure
Create a custom resource (CR) file for the Ingress Controller:
Example of a CR file that defines information for the
IngressController
objectapiVersion: v1 items: - apiVersion: operator.openshift.io/v1 kind: IngressController metadata: name: <custom_ic_name> 1 namespace: openshift-ingress-operator spec: replicas: 1 domain: <custom_ic_domain_name> 2 nodePlacement: nodeSelector: matchLabels: <key>: <value> 3 namespaceSelector: matchLabels: <key>: <value> 4 endpointPublishingStrategy: type: NodePortService # ...
- 1
- Specify the a custom
name
for theIngressController
CR. - 2
- The DNS name that the Ingress Controller services. As an example, the default ingresscontroller domain is
apps.ipi-cluster.example.com
, so you would specify the<custom_ic_domain_name>
asnodeportsvc.ipi-cluster.example.com
. - 3
- Specify the label for the nodes that include the custom Ingress Controller.
- 4
- Specify the label for a set of namespaces. Substitute
<key>:<value>
with a map of key-value pairs where<key>
is a unique name for the new label and<value>
is its value. For example:ingresscontroller: custom-ic
.
Add a label to a node by using the
oc label node
command:$ oc label node <node_name> <key>=<value> 1
- 1
- Where
<value>
must match the key-value pair specified in thenodePlacement
section of yourIngressController
CR.
Create the
IngressController
object:$ oc create -f <ingress_controller_cr>.yaml
Find the port for the service created for the
IngressController
CR:$ oc get svc -n openshift-ingress
Example output that shows port
80:32432/TCP
for therouter-nodeport-custom-ic3
serviceNAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE router-internal-default ClusterIP 172.30.195.74 <none> 80/TCP,443/TCP,1936/TCP 223d router-nodeport-custom-ic3 NodePort 172.30.109.219 <none> 80:32432/TCP,443:31366/TCP,1936:30499/TCP 155m
To create a new project, enter the following command:
$ oc new-project <project_name>
To label the new namespace, enter the following command:
$ oc label namespace <project_name> <key>=<value> 1
- 1
- Where
<key>=<value>
must match the value in thenamespaceSelector
section of your Ingress Controller CR.
Create a new application in your cluster:
$ oc new-app --image=<image_name> 1
- 1
- An example of
<image_name>
isquay.io/openshifttest/hello-openshift:multiarch
.
Create a
Route
object for a service, so that the pod can use the service to expose the application external to the cluster.$ oc expose svc/<service_name> --hostname=<svc_name>-<project_name>.<custom_ic_domain_name> 1
NoteYou must specify the domain name of your custom Ingress Controller in the
--hostname
argument. If you do not do this, the Ingress Operator uses the default Ingress Controller to serve all the routes for your cluster.Check that the route has the
Admitted
status and that it includes metadata for the custom Ingress Controller:$ oc get route/hello-openshift -o json | jq '.status.ingress'
Example output
# ... { "conditions": [ { "lastTransitionTime": "2024-05-17T18:25:41Z", "status": "True", "type": "Admitted" } ], [ { "host": "hello-openshift.nodeportsvc.ipi-cluster.example.com", "routerCanonicalHostname": "router-nodeportsvc.nodeportsvc.ipi-cluster.example.com", "routerName": "nodeportsvc", "wildcardPolicy": "None" } ], }
Update the default
IngressController
CR to prevent the default Ingress Controller from managing theNodePort
-typeService
. The default Ingress Controller will continue to monitor all other cluster traffic.$ oc patch --type=merge -n openshift-ingress-operator ingresscontroller/default --patch '{"spec":{"namespaceSelector":{"matchExpressions":[{"key":"<key>","operator":"NotIn","values":["<value>]}]}}}'
Verification
Verify that the DNS entry can route inside and outside of your cluster by entering the following command. The command outputs the IP address of the node that received the label from running the
oc label node
command earlier in the procedure.$ dig +short <svc_name>-<project_name>.<custom_ic_domain_name>
To verify that your cluster uses the IP addresses from external DNS servers for DNS resolution, check the connection of your cluster by entering the following command:
$ curl <svc_name>-<project_name>.<custom_ic_domain_name>:<port> 1
Output example
Hello OpenShift!
22.4.2. Additional resources
22.5. Configuring ingress cluster traffic using a load balancer
OpenShift Container Platform provides methods for communicating from outside the cluster with services running in the cluster. This method uses a load balancer.
22.5.1. Using a load balancer to get traffic into the cluster
If you do not need a specific external IP address, you can configure a load balancer service to allow external access to an OpenShift Container Platform cluster.
A load balancer service allocates a unique IP. The load balancer has a single edge router IP, which can be a virtual IP (VIP), but is still a single machine for initial load balancing.
If a pool is configured, it is done at the infrastructure level, not by a cluster administrator.
The procedures in this section require prerequisites performed by the cluster administrator.
22.5.2. Prerequisites
Before starting the following procedures, the administrator must:
- Set up the external port to the cluster networking environment so that requests can reach the cluster.
Make sure there is at least one user with cluster admin role. To add this role to a user, run the following command:
$ oc adm policy add-cluster-role-to-user cluster-admin username
- Have an OpenShift Container Platform cluster with at least one master and at least one node and a system outside the cluster that has network access to the cluster. This procedure assumes that the external system is on the same subnet as the cluster. The additional networking required for external systems on a different subnet is out-of-scope for this topic.
22.5.3. Creating a project and service
If the project and service that you want to expose does not exist, create the project and then create the service.
If the project and service already exists, skip to the procedure on exposing the service to create a route.
Prerequisites
-
Install the OpenShift CLI (
oc
) and log in as a cluster administrator.
Procedure
Create a new project for your service by running the
oc new-project
command:$ oc new-project <project_name>
Use the
oc new-app
command to create your service:$ oc new-app nodejs:12~https://github.com/sclorg/nodejs-ex.git
To verify that the service was created, run the following command:
$ oc get svc -n <project_name>
Example output
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE nodejs-ex ClusterIP 172.30.197.157 <none> 8080/TCP 70s
NoteBy default, the new service does not have an external IP address.
22.5.4. Exposing the service by creating a route
You can expose the service as a route by using the oc expose
command.
Prerequisites
- You logged into OpenShift Container Platform.
Procedure
Log in to the project where the service you want to expose is located:
$ oc project <project_name>
Run the
oc expose service
command to expose the route:$ oc expose service nodejs-ex
Example output
route.route.openshift.io/nodejs-ex exposed
To verify that the service is exposed, you can use a tool, such as
curl
to check that the service is accessible from outside the cluster.To find the hostname of the route, enter the following command:
$ oc get route
Example output
NAME HOST/PORT PATH SERVICES PORT TERMINATION WILDCARD nodejs-ex nodejs-ex-myproject.example.com nodejs-ex 8080-tcp None
To check that the host responds to a GET request, enter the following command:
Example
curl
command$ curl --head nodejs-ex-myproject.example.com
Example output
HTTP/1.1 200 OK ...
22.5.5. Creating a load balancer service
Use the following procedure to create a load balancer service.
Prerequisites
- Make sure that the project and service you want to expose exist.
- Your cloud provider supports load balancers.
Procedure
To create a load balancer service:
- Log in to OpenShift Container Platform.
Load the project where the service you want to expose is located.
$ oc project project1
Open a text file on the control plane node and paste the following text, editing the file as needed:
Sample load balancer configuration file
apiVersion: v1 kind: Service metadata: name: egress-2 1 spec: ports: - name: db port: 3306 2 loadBalancerIP: loadBalancerSourceRanges: 3 - 10.0.0.0/8 - 192.168.0.0/16 type: LoadBalancer 4 selector: name: mysql 5
- 1
- Enter a descriptive name for the load balancer service.
- 2
- Enter the same port that the service you want to expose is listening on.
- 3
- Enter a list of specific IP addresses to restrict traffic through the load balancer. This field is ignored if the cloud-provider does not support the feature.
- 4
- Enter
Loadbalancer
as the type. - 5
- Enter the name of the service.
NoteTo restrict the traffic through the load balancer to specific IP addresses, it is recommended to use the Ingress Controller field
spec.endpointPublishingStrategy.loadBalancer.allowedSourceRanges
. Do not set theloadBalancerSourceRanges
field.- Save and exit the file.
Run the following command to create the service:
$ oc create -f <file-name>
For example:
$ oc create -f mysql-lb.yaml
Execute the following command to view the new service:
$ oc get svc
Example output
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE egress-2 LoadBalancer 172.30.22.226 ad42f5d8b303045-487804948.example.com 3306:30357/TCP 15m
The service has an external IP address automatically assigned if there is a cloud provider enabled.
On the master, use a tool, such as cURL, to make sure you can reach the service using the public IP address:
$ curl <public-ip>:<port>
For example:
$ curl 172.29.121.74:3306
The examples in this section use a MySQL service, which requires a client application. If you get a string of characters with the
Got packets out of order
message, you are connecting with the service:If you have a MySQL client, log in with the standard CLI command:
$ mysql -h 172.30.131.89 -u admin -p
Example output
Enter password: Welcome to the MariaDB monitor. Commands end with ; or \g. MySQL [(none)]>
22.6. Configuring ingress cluster traffic on AWS
OpenShift Container Platform provides methods for communicating from outside the cluster with services running in the cluster. This method uses load balancers on AWS, specifically a Network Load Balancer (NLB) or a Classic Load Balancer (CLB). Both types of load balancers can forward the client’s IP address to the node, but a CLB requires proxy protocol support, which OpenShift Container Platform automatically enables.
There are two ways to configure an Ingress Controller to use an NLB:
-
By force replacing the Ingress Controller that is currently using a CLB. This deletes the
IngressController
object and an outage will occur while the new DNS records propagate and the NLB is being provisioned. -
By editing an existing Ingress Controller that uses a CLB to use an NLB. This changes the load balancer without having to delete and recreate the
IngressController
object.
Both methods can be used to switch from an NLB to a CLB.
You can configure these load balancers on a new or existing AWS cluster.
22.6.1. Configuring Classic Load Balancer timeouts on AWS
OpenShift Container Platform provides a method for setting a custom timeout period for a specific route or Ingress Controller. Additionally, an AWS Classic Load Balancer (CLB) has its own timeout period with a default time of 60 seconds.
If the timeout period of the CLB is shorter than the route timeout or Ingress Controller timeout, the load balancer can prematurely terminate the connection. You can prevent this problem by increasing both the timeout period of the route and CLB.
22.6.1.1. Configuring route timeouts
You can configure the default timeouts for an existing route when you have services in need of a low timeout, which is required for Service Level Availability (SLA) purposes, or a high timeout, for cases with a slow back end.
Prerequisites
- You need a deployed Ingress Controller on a running cluster.
Procedure
Using the
oc annotate
command, add the timeout to the route:$ oc annotate route <route_name> \ --overwrite haproxy.router.openshift.io/timeout=<timeout><time_unit> 1
- 1
- Supported time units are microseconds (us), milliseconds (ms), seconds (s), minutes (m), hours (h), or days (d).
The following example sets a timeout of two seconds on a route named
myroute
:$ oc annotate route myroute --overwrite haproxy.router.openshift.io/timeout=2s
22.6.1.2. Configuring Classic Load Balancer timeouts
You can configure the default timeouts for a Classic Load Balancer (CLB) to extend idle connections.
Prerequisites
- You must have a deployed Ingress Controller on a running cluster.
Procedure
Set an AWS connection idle timeout of five minutes for the default
ingresscontroller
by running the following command:$ oc -n openshift-ingress-operator patch ingresscontroller/default \ --type=merge --patch='{"spec":{"endpointPublishingStrategy": \ {"type":"LoadBalancerService", "loadBalancer": \ {"scope":"External", "providerParameters":{"type":"AWS", "aws": \ {"type":"Classic", "classicLoadBalancer": \ {"connectionIdleTimeout":"5m"}}}}}}}'
Optional: Restore the default value of the timeout by running the following command:
$ oc -n openshift-ingress-operator patch ingresscontroller/default \ --type=merge --patch='{"spec":{"endpointPublishingStrategy": \ {"loadBalancer":{"providerParameters":{"aws":{"classicLoadBalancer": \ {"connectionIdleTimeout":null}}}}}}}'
You must specify the scope
field when you change the connection timeout value unless the current scope is already set. When you set the scope
field, you do not need to do so again if you restore the default timeout value.
22.6.2. Configuring ingress cluster traffic on AWS using a Network Load Balancer
OpenShift Container Platform provides methods for communicating from outside the cluster with services that run in the cluster. One such method uses a Network Load Balancer (NLB). You can configure an NLB on a new or existing AWS cluster.
22.6.2.1. Switching the Ingress Controller from using a Classic Load Balancer to a Network Load Balancer
You can switch the Ingress Controller that is using a Classic Load Balancer (CLB) to one that uses a Network Load Balancer (NLB) on AWS.
Switching between these load balancers will not delete the IngressController
object.
This procedure might cause the following issues:
- An outage that can last several minutes due to new DNS records propagation, new load balancers provisioning, and other factors. IP addresses and canonical names of the Ingress Controller load balancer might change after applying this procedure.
- Leaked load balancer resources due to a change in the annotation of the service.
Procedure
Modify the existing Ingress Controller that you want to switch to using an NLB. This example assumes that your default Ingress Controller has an
External
scope and no other customizations:Example
ingresscontroller.yaml
fileapiVersion: operator.openshift.io/v1 kind: IngressController metadata: creationTimestamp: null name: default namespace: openshift-ingress-operator spec: endpointPublishingStrategy: loadBalancer: scope: External providerParameters: type: AWS aws: type: NLB type: LoadBalancerService
NoteIf you do not specify a value for the
spec.endpointPublishingStrategy.loadBalancer.providerParameters.aws.type
field, the Ingress Controller uses thespec.loadBalancer.platform.aws.type
value from the clusterIngress
configuration that was set during installation.TipIf your Ingress Controller has other customizations that you want to update, such as changing the domain, consider force replacing the Ingress Controller definition file instead.
Apply the changes to the Ingress Controller YAML file by running the command:
$ oc apply -f ingresscontroller.yaml
Expect several minutes of outages while the Ingress Controller updates.
22.6.2.2. Switching the Ingress Controller from using a Network Load Balancer to a Classic Load Balancer
You can switch the Ingress Controller that is using a Network Load Balancer (NLB) to one that uses a Classic Load Balancer (CLB) on AWS.
Switching between these load balancers will not delete the IngressController
object.
This procedure might cause an outage that can last several minutes due to new DNS records propagation, new load balancers provisioning, and other factors. IP addresses and canonical names of the Ingress Controller load balancer might change after applying this procedure.
Procedure
Modify the existing Ingress Controller that you want to switch to using a CLB. This example assumes that your default Ingress Controller has an
External
scope and no other customizations:Example
ingresscontroller.yaml
fileapiVersion: operator.openshift.io/v1 kind: IngressController metadata: creationTimestamp: null name: default namespace: openshift-ingress-operator spec: endpointPublishingStrategy: loadBalancer: scope: External providerParameters: type: AWS aws: type: Classic type: LoadBalancerService
NoteIf you do not specify a value for the
spec.endpointPublishingStrategy.loadBalancer.providerParameters.aws.type
field, the Ingress Controller uses thespec.loadBalancer.platform.aws.type
value from the clusterIngress
configuration that was set during installation.TipIf your Ingress Controller has other customizations that you want to update, such as changing the domain, consider force replacing the Ingress Controller definition file instead.
Apply the changes to the Ingress Controller YAML file by running the command:
$ oc apply -f ingresscontroller.yaml
Expect several minutes of outages while the Ingress Controller updates.
22.6.2.3. Replacing Ingress Controller Classic Load Balancer with Network Load Balancer
You can replace an Ingress Controller that is using a Classic Load Balancer (CLB) with one that uses a Network Load Balancer (NLB) on AWS.
This procedure might cause the following issues:
- An outage that can last several minutes due to new DNS records propagation, new load balancers provisioning, and other factors. IP addresses and canonical names of the Ingress Controller load balancer might change after applying this procedure.
- Leaked load balancer resources due to a change in the annotation of the service.
Procedure
Create a file with a new default Ingress Controller. The following example assumes that your default Ingress Controller has an
External
scope and no other customizations:Example
ingresscontroller.yml
fileapiVersion: operator.openshift.io/v1 kind: IngressController metadata: creationTimestamp: null name: default namespace: openshift-ingress-operator spec: endpointPublishingStrategy: loadBalancer: scope: External providerParameters: type: AWS aws: type: NLB type: LoadBalancerService
If your default Ingress Controller has other customizations, ensure that you modify the file accordingly.
TipIf your Ingress Controller has no other customizations and you are only updating the load balancer type, consider following the procedure detailed in "Switching the Ingress Controller from using a Classic Load Balancer to a Network Load Balancer".
Force replace the Ingress Controller YAML file:
$ oc replace --force --wait -f ingresscontroller.yml
Wait until the Ingress Controller is replaced. Expect several of minutes of outages.
22.6.2.4. Configuring an Ingress Controller Network Load Balancer on an existing AWS cluster
You can create an Ingress Controller backed by an AWS Network Load Balancer (NLB) on an existing cluster.
Prerequisites
- You must have an installed AWS cluster.
PlatformStatus
of the infrastructure resource must be AWS.To verify that the
PlatformStatus
is AWS, run:$ oc get infrastructure/cluster -o jsonpath='{.status.platformStatus.type}' AWS
Procedure
Create an Ingress Controller backed by an AWS NLB on an existing cluster.
Create the Ingress Controller manifest:
$ cat ingresscontroller-aws-nlb.yaml
Example output
apiVersion: operator.openshift.io/v1 kind: IngressController metadata: name: $my_ingress_controller1 namespace: openshift-ingress-operator spec: domain: $my_unique_ingress_domain2 endpointPublishingStrategy: type: LoadBalancerService loadBalancer: scope: External3 providerParameters: type: AWS aws: type: NLB
- 1
- Replace
$my_ingress_controller
with a unique name for the Ingress Controller. - 2
- Replace
$my_unique_ingress_domain
with a domain name that is unique among all Ingress Controllers in the cluster. This variable must be a subdomain of the DNS name<clustername>.<domain>
. - 3
- You can replace
External
withInternal
to use an internal NLB.
Create the resource in the cluster:
$ oc create -f ingresscontroller-aws-nlb.yaml
Before you can configure an Ingress Controller NLB on a new AWS cluster, you must complete the Creating the installation configuration file procedure.
22.6.2.5. Configuring an Ingress Controller Network Load Balancer on a new AWS cluster
You can create an Ingress Controller backed by an AWS Network Load Balancer (NLB) on a new cluster.
Prerequisites
-
Create the
install-config.yaml
file and complete any modifications to it.
Procedure
Create an Ingress Controller backed by an AWS NLB on a new cluster.
Change to the directory that contains the installation program and create the manifests:
$ ./openshift-install create manifests --dir <installation_directory> 1
- 1
- For
<installation_directory>
, specify the name of the directory that contains theinstall-config.yaml
file for your cluster.
Create a file that is named
cluster-ingress-default-ingresscontroller.yaml
in the<installation_directory>/manifests/
directory:$ touch <installation_directory>/manifests/cluster-ingress-default-ingresscontroller.yaml 1
- 1
- For
<installation_directory>
, specify the directory name that contains themanifests/
directory for your cluster.
After creating the file, several network configuration files are in the
manifests/
directory, as shown:$ ls <installation_directory>/manifests/cluster-ingress-default-ingresscontroller.yaml
Example output
cluster-ingress-default-ingresscontroller.yaml
Open the
cluster-ingress-default-ingresscontroller.yaml
file in an editor and enter a custom resource (CR) that describes the Operator configuration you want:apiVersion: operator.openshift.io/v1 kind: IngressController metadata: creationTimestamp: null name: default namespace: openshift-ingress-operator spec: endpointPublishingStrategy: loadBalancer: scope: External providerParameters: type: AWS aws: type: NLB type: LoadBalancerService
-
Save the
cluster-ingress-default-ingresscontroller.yaml
file and quit the text editor. -
Optional: Back up the
manifests/cluster-ingress-default-ingresscontroller.yaml
file. The installation program deletes themanifests/
directory when creating the cluster.
22.6.3. Additional resources
- Installing a cluster on AWS with network customizations.
- For more information on support for NLBs, see Network Load Balancer support on AWS.
- For more information on proxy protocol support for CLBs, see Configure proxy protocol support for your Classic Load Balancer
22.7. Configuring ingress cluster traffic for a service external IP
You can use either a MetalLB implementation or an IP failover deployment to attach an ExternalIP resource to a service so that the service is available to traffic outside your OpenShift Container Platform cluster. Hosting an external IP address in this way is only applicable for a cluster installed on bare-metal hardware.
You must ensure that you correctly configure the external network infrastructure to route traffic to the service.
22.7.1. Prerequisites
Your cluster is configured with ExternalIPs enabled. For more information, read Configuring ExternalIPs for services.
NoteDo not use the same ExternalIP for the egress IP.
22.7.2. Attaching an ExternalIP to a service
You can attach an ExternalIP resource to a service. If you configured your cluster to automatically attach the resource to a service, you might not need to manually attach an ExternalIP to the service.
The examples in the procedure use a scenario that manually attaches an ExternalIP resource to a service in a cluster with an IP failover configuration.
Procedure
Confirm compatible IP address ranges for the ExternalIP resource by entering the following command in your CLI:
$ oc get networks.config cluster -o jsonpath='{.spec.externalIP}{"\n"}'
NoteIf
autoAssignCIDRs
is set and you did not specify a value forspec.externalIPs
in the ExternalIP resource, OpenShift Container Platform automatically assigns ExternalIP to a newService
object.Choose one of the following options to attach an ExternalIP resource to the service:
If you are creating a new service, specify a value in the
spec.externalIPs
field and array of one or more valid IP addresses in theallowedCIDRs
parameter.Example of service YAML configuration file that supports an ExternalIP resource
apiVersion: v1 kind: Service metadata: name: svc-with-externalip spec: externalIPs: policy: allowedCIDRs: - 192.168.123.0/28
If you are attaching an ExternalIP to an existing service, enter the following command. Replace
<name>
with the service name. Replace<ip_address>
with a valid ExternalIP address. You can provide multiple IP addresses separated by commas.$ oc patch svc <name> -p \ '{ "spec": { "externalIPs": [ "<ip_address>" ] } }'
For example:
$ oc patch svc mysql-55-rhel7 -p '{"spec":{"externalIPs":["192.174.120.10"]}}'
Example output
"mysql-55-rhel7" patched
To confirm that an ExternalIP address is attached to the service, enter the following command. If you specified an ExternalIP for a new service, you must create the service first.
$ oc get svc
Example output
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE mysql-55-rhel7 172.30.131.89 192.174.120.10 3306/TCP 13m
22.7.3. Additional resources
22.8. Configuring ingress cluster traffic by using a NodePort
OpenShift Container Platform provides methods for communicating from outside the cluster with services running in the cluster. This method uses a NodePort
.
22.8.1. Using a NodePort to get traffic into the cluster
Use a NodePort
-type Service
resource to expose a service on a specific port on all nodes in the cluster. The port is specified in the Service
resource’s .spec.ports[*].nodePort
field.
Using a node port requires additional port resources.
A NodePort
exposes the service on a static port on the node’s IP address. NodePort
s are in the 30000
to 32767
range by default, which means a NodePort
is unlikely to match a service’s intended port. For example, port 8080
may be exposed as port 31020
on the node.
The administrator must ensure the external IP addresses are routed to the nodes.
NodePort
s and external IPs are independent and both can be used concurrently.
The procedures in this section require prerequisites performed by the cluster administrator.
22.8.2. Prerequisites
Before starting the following procedures, the administrator must:
- Set up the external port to the cluster networking environment so that requests can reach the cluster.
Make sure there is at least one user with cluster admin role. To add this role to a user, run the following command:
$ oc adm policy add-cluster-role-to-user cluster-admin <user_name>
- Have an OpenShift Container Platform cluster with at least one master and at least one node and a system outside the cluster that has network access to the cluster. This procedure assumes that the external system is on the same subnet as the cluster. The additional networking required for external systems on a different subnet is out-of-scope for this topic.
22.8.3. Creating a project and service
If the project and service that you want to expose does not exist, create the project and then create the service.
If the project and service already exists, skip to the procedure on exposing the service to create a route.
Prerequisites
-
Install the OpenShift CLI (
oc
) and log in as a cluster administrator.
Procedure
Create a new project for your service by running the
oc new-project
command:$ oc new-project <project_name>
Use the
oc new-app
command to create your service:$ oc new-app nodejs:12~https://github.com/sclorg/nodejs-ex.git
To verify that the service was created, run the following command:
$ oc get svc -n <project_name>
Example output
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE nodejs-ex ClusterIP 172.30.197.157 <none> 8080/TCP 70s
NoteBy default, the new service does not have an external IP address.
22.8.4. Exposing the service by creating a route
You can expose the service as a route by using the oc expose
command.
Prerequisites
- You logged into OpenShift Container Platform.
Procedure
Log in to the project where the service you want to expose is located:
$ oc project <project_name>
To expose a node port for the application, modify the custom resource definition (CRD) of a service by entering the following command:
$ oc edit svc <service_name>
Example output
spec: ports: - name: 8443-tcp nodePort: 30327 1 port: 8443 protocol: TCP targetPort: 8443 sessionAffinity: None type: NodePort 2
Optional: To confirm the service is available with a node port exposed, enter the following command:
$ oc get svc -n myproject
Example output
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE nodejs-ex ClusterIP 172.30.217.127 <none> 3306/TCP 9m44s nodejs-ex-ingress NodePort 172.30.107.72 <none> 3306:31345/TCP 39s
Optional: To remove the service created automatically by the
oc new-app
command, enter the following command:$ oc delete svc nodejs-ex
Verification
To check that the service node port is updated with a port in the
30000-32767
range, enter the following command:$ oc get svc
In the following example output, the updated port is
30327
:Example output
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE httpd NodePort 172.xx.xx.xx <none> 8443:30327/TCP 109s
22.8.5. Additional resources
22.9. Configuring ingress cluster traffic using load balancer allowed source ranges
You can specify a list of IP address ranges for the IngressController
. This restricts access to the load balancer service when the endpointPublishingStrategy
is LoadBalancerService
.
22.9.1. Configuring load balancer allowed source ranges
You can enable and configure the spec.endpointPublishingStrategy.loadBalancer.allowedSourceRanges
field. By configuring load balancer allowed source ranges, you can limit the access to the load balancer for the Ingress Controller to a specified list of IP address ranges. The Ingress Operator reconciles the load balancer Service and sets the spec.loadBalancerSourceRanges
field based on AllowedSourceRanges
.
If you have already set the spec.loadBalancerSourceRanges
field or the load balancer service anotation service.beta.kubernetes.io/load-balancer-source-ranges
in a previous version of OpenShift Container Platform, Ingress Controller starts reporting Progressing=True
after an upgrade. To fix this, set AllowedSourceRanges
that overwrites the spec.loadBalancerSourceRanges
field and clears the service.beta.kubernetes.io/load-balancer-source-ranges
annotation. Ingress Controller starts reporting Progressing=False
again.
Prerequisites
- You have a deployed Ingress Controller on a running cluster.
Procedure
Set the allowed source ranges API for the Ingress Controller by running the following command:
$ oc -n openshift-ingress-operator patch ingresscontroller/default \ --type=merge --patch='{"spec":{"endpointPublishingStrategy": \ {"type":"LoadBalancerService", "loadbalancer": \ {"scope":"External", "allowedSourceRanges":["0.0.0.0/0"]}}}}' 1
- 1
- The example value
0.0.0.0/0
specifies the allowed source range.
22.9.2. Migrating to load balancer allowed source ranges
If you have already set the annotation service.beta.kubernetes.io/load-balancer-source-ranges
, you can migrate to load balancer allowed source ranges. When you set the AllowedSourceRanges
, the Ingress Controller sets the spec.loadBalancerSourceRanges
field based on the AllowedSourceRanges
value and unsets the service.beta.kubernetes.io/load-balancer-source-ranges
annotation.
If you have already set the spec.loadBalancerSourceRanges
field or the load balancer service anotation service.beta.kubernetes.io/load-balancer-source-ranges
in a previous version of OpenShift Container Platform, the Ingress Controller starts reporting Progressing=True
after an upgrade. To fix this, set AllowedSourceRanges
that overwrites the spec.loadBalancerSourceRanges
field and clears the service.beta.kubernetes.io/load-balancer-source-ranges
annotation. The Ingress Controller starts reporting Progressing=False
again.
Prerequisites
-
You have set the
service.beta.kubernetes.io/load-balancer-source-ranges
annotation.
Procedure
Ensure that the
service.beta.kubernetes.io/load-balancer-source-ranges
is set:$ oc get svc router-default -n openshift-ingress -o yaml
Example output
apiVersion: v1 kind: Service metadata: annotations: service.beta.kubernetes.io/load-balancer-source-ranges: 192.168.0.1/32
Ensure that the
spec.loadBalancerSourceRanges
field is unset:$ oc get svc router-default -n openshift-ingress -o yaml
Example output
... spec: loadBalancerSourceRanges: - 0.0.0.0/0 ...
- Update your cluster to OpenShift Container Platform 4.17.
Set the allowed source ranges API for the
ingresscontroller
by running the following command:$ oc -n openshift-ingress-operator patch ingresscontroller/default \ --type=merge --patch='{"spec":{"endpointPublishingStrategy": \ {"loadBalancer":{"allowedSourceRanges":["0.0.0.0/0"]}}}}' 1
- 1
- The example value
0.0.0.0/0
specifies the allowed source range.