Chapter 24. Configuring for Azure


You can configure OpenShift Container Platform to use Microsoft Azure load balancers and disks for persistent application data.

24.1. Before you begin

24.1.1. Configuring authorization for Microsoft Azure

Azure roles

Configuring Microsoft Azure for OpenShift Container Platform requires the following Microsoft Azure role:

Contributor

To create and manage all types of Microsoft Azure resources.

See the Classic subscription administrator roles vs. Azure RBAC roles vs. Azure AD administrator roles documentation for more information.

Permissions

Configuring Microsoft Azure for OpenShift Container Platform requires a service principal, which allows the creation and management of Kubernetes service load balancers and disks for persistent storage. The service principal values are defined at installation time and deployed to the Azure configuration file, located at /etc/origin/cloudprovider/azure.conf on OpenShift Container Platform master and node hosts.

Procedure

  1. Using the Azure CLI, obtain the account subscription ID:

    # az account list
    [
    {
      "cloudName": "AzureCloud",
      "id": "<subscription>", 1
      "isDefault": false,
      "name": "Pay-As-You-Go",
      "state": "Enabled",
      "tenantId": "<tenant-id>",
      "user": {
        "name": "admin@example.com",
        "type": "user"
      }
    ]
    1
    The subscription ID to use to create the new permissions.
  2. Create the service principal with the Microsoft Azure role of contributor and with the scope of the Microsoft Azure subscription and the resource group. Record the output of these values to be used when defining the inventory. Use the <subscription> value from the previous step in place of the value below:

    # az ad sp create-for-rbac --name openshiftcloudprovider \
         --password <secret> --role contributor \
         --scopes /subscriptions/<subscription>/resourceGroups/<resource-group>
    
    Retrying role assignment creation: 1/36
    Retrying role assignment creation: 2/36
    {
      "appId": "<app-id>",
      "displayName": "ocpcloudprovider",
      "name": "http://ocpcloudprovider",
      "password": "<secret>",
      "tenant": "<tenant-id>"
    }

24.1.2. Configuring Microsoft Azure objects

Integrating OpenShift Container Platform with Microsoft Azure requires the following components or services to create a highly-available and full-featured environment.

Important

To ensure that the appropriate amount of instances can be launched, request an increase in CPU quota from Microsoft before creating instances.

A resource group
Resource groups contain all Microsoft Azure components for a deployment, including networking, load balancers, virtual machines, and DNS. Quotas and permissions can be applied to resources groups to control and manage resources deployed on Microsoft Azure. Resource groups are created and defined per geographic region. All resources created for an OpenShift Container Platform environment should be within the same geographic region and within the same resource group.

See Azure Resource Manager overview for more information.

Azure Virtual Networks
Azure Virtual Networks are used to isolate Azure cloud networks from one another. Instances and load balancers use the virtual network to allow communication with each other and to and from the Internet. The virtual network allows for the creation of one or many subnets to be used by components within a resource group. You can also connect virtual networks to various VPN services, allowing communication with on-premise services.

See What is Azure Virtual Network? for more information.

Azure DNS
Azure offers a managed DNS service that provides internal and Internet-accessible host name and load balancer resolution. The reference environment uses a DNS zone to host three DNS A records to allow for mapping of public IPs to OpenShift Container Platform resources and a bastion.

See What is Azure DNS? for more information.

Load balancing
Azure load balancers allow network connectivity for scaling and high availability of services running on virtual machines within the Azure environment.

See What is Azure Load Balancer?

Storage Account
Storage Accounts allow for resources, such as virtual machines, to access the different type of storage components offered by Microsoft Azure. During installation, the storage account defines the location of the object-based blob storage used for the OpenShift Container Platform registry.

See Introduction to Azure Storage for more information, or the Configuring the OpenShift Container Platform registry for Microsoft Azure section for steps to create the storage account for the registry.

Service Principal
Azure offers the ability to create service accounts, which access, manage, or create components within Azure. The service account grants API access to specific services. For example, a service principal allows Kubernetes or OpenShift Container Platform instances to request persistent storage and load balancers. Service principals allow for granular access to be given to instances or users for specific functions.

See Application and service principal objects in Azure Active Directory for more information.

Availability Sets
Availability sets ensure that the deployed VMs are distributed across multiple isolated hardware nodes in a cluster. The distribution helps to ensure that when maintenance on the cloud provider hardware occurs, instances will not all run on one specific node.

You should segment instances to different availability sets based on their role. For example, one availability set containing three master hosts, one availability set containing infrastructure hosts, and one availability set containing application hosts. This allows for segmentation and the ability to use external load balancers within OpenShift Container Platform.

See Manage the availability of Linux virtual machines for more information.

Network Security Groups
Network Security Groups (NSGs) provide a list of rules to either allow or deny traffic to resources deployed within an Azure Virtual Network. NSGs use numeric priority values and rules to define what items are allowed to communicate with each other. You can place restrictions on where communication is allowed to occur, such as within only the virtual network, from load balancers, or from everywhere.

Priority values allow for administrators to grant granular values on the order in which port communication is allowed or not allowed to occur.

See Plan virtual networks for more information.

Instances sizes
A successful OpenShift Container Platform environment requires some minimum hardware requirements.

See the Minimum Hadware Requirements section in the OpenShift Container Platform documentation or Sizes for Cloud Services for more information.

24.2. The Azure configuration file

Configuring OpenShift Container Platform for Azure requires the /etc/azure/azure.conf file, on each node host.

If the file does not exist, you can create it.

tenantId: <> 1
subscriptionId: <> 2
aadClientId: <> 3
aadClientSecret: <> 4
aadTenantId: <> 5
resourceGroup: <> 6
cloud: <> 7
location: <> 8
vnetName: <> 9
securityGroupName: <> 10
primaryAvailabilitySetName: <> 11
1
The AAD tenant ID for the subscription that the cluster is deployed in.
2
The Azure subscription ID that the cluster is deployed in.
3
The client ID for an AAD application with RBAC access to talk to Azure RM APIs.
4
The client secret for an AAD application with RBAC access to talk to Azure RM APIs.
5
Ensure this is the same as tenant ID (optional).
6
The Azure Resource Group name that the Azure VM belongs to.
7
The specific cloud region. For example, AzurePublicCloud.
8
The compact style Azure region. For example, southeastasia (optional).
9
Virtual network containing instances and used when creating load balancers.
10
Security group name associated with instances and load balancers.
11
Availability set to use when creating resources such as load balancers (optional).
Important

The NIC used for accessing the instance must have an internal-dns-name set or the node will not be able to rejoin the cluster, display build logs to the console, and will cause oc rsh to not work correctly.

24.3. Example inventory for OpenShift Container Platform on Microsoft Azure

The example inventory below assumes that the following items have been created:

  • A resource group
  • An Azure virtual network
  • One or more network security groups that contain the required OpenShift Container Platform ports
  • A storage account
  • A service principal
  • Two load balancers
  • Two or more DNS entries for the routers and for the OpenShift Container Platform web console
  • Three Availability Sets
  • Three master instances
  • Three infrastructure instances
  • One or more application instances

The inventory below uses the default storageclass to create persistent volumes to be used by the metrics, logging, and service catalog components managed by a service principal. The registry uses Microsoft Azure blob storage.

Important

If the Microsoft Azure instances use managed disks, provide the following variable in the inventory:

openshift_storageclass_parameters={'kind': 'managed', 'storageaccounttype': 'Premium_LRS'}

or

openshift_storageclass_parameters={'kind': 'managed', 'storageaccounttype': 'Standard_LRS'}

This ensures the storageclass creates the correct disk type for PVs as it relates to the instances deployed. If unmanaged disks are used, the storageclass will use the shared parameter allowing for unmanged disks to be created for PVs.

[OSEv3:children]
masters
etcd
nodes

[OSEv3:vars]
ansible_ssh_user=cloud-user
ansible_become=true
openshift_cloudprovider_kind=azure

#cloudprovider
openshift_cloudprovider_kind=azure
openshift_cloudprovider_azure_client_id=v9c97ead-1v7E-4175-93e3-623211bed834
openshift_cloudprovider_azure_client_secret=s3r3tR3gistryN0special
openshift_cloudprovider_azure_tenant_id=422r3f91-21fe-4esb-vad5-d96dfeooee5d
openshift_cloudprovider_azure_subscription_id=6003c1c9-d10d-4366-86cc-e3ddddcooe2d
openshift_cloudprovider_azure_resource_group=openshift
openshift_cloudprovider_azure_location=eastus
#endcloudprovider

oreg_auth_user=service_account 1
oreg_auth_password=service_account_token 2
openshift_master_api_port=443
openshift_master_console_port=443
openshift_hosted_router_replicas=3
openshift_hosted_registry_replicas=1
openshift_master_cluster_method=native
openshift_master_cluster_hostname=openshift-master.example.com
openshift_master_cluster_public_hostname=openshift-master.example.com
openshift_master_default_subdomain=apps.openshift.example.com
openshift_deployment_type=openshift-enterprise
openshift_master_identity_providers=[{'name': 'idm', 'challenge': 'true', 'login': 'true', 'kind': 'LDAPPasswordIdentityProvider', 'attributes': {'id': ['dn'], 'email': ['mail'], 'name': ['cn'], 'preferredUsername': ['uid']}, 'bindDN': 'uid=admin,cn=users,cn=accounts,dc=example,dc=com', 'bindPassword': 'ldapadmin', 'ca': '/etc/origin/master/ca.crt', 'insecure': 'false', 'url': 'ldap://ldap.example.com/cn=users,cn=accounts,dc=example,dc=com?uid?sub?(memberOf=cn=ose-user,cn=groups,cn=accounts,dc=example,dc=com)'}]
networkPluginName=redhat/ovs-networkpolicy
openshift_examples_modify_imagestreams=true


# Storage Class change to use managed storage
openshift_storageclass_parameters={'kind': 'managed', 'storageaccounttype': 'Standard_LRS'}

# service catalog
openshift_enable_service_catalog=true
openshift_hosted_etcd_storage_kind=dynamic
openshift_hosted_etcd_storage_volume_name=etcd-vol
openshift_hosted_etcd_storage_access_modes=["ReadWriteOnce"]
openshift_hosted_etcd_storage_volume_size=SC_STORAGE
openshift_hosted_etcd_storage_labels={'storage': 'etcd'}

# metrics
openshift_metrics_install_metrics=true
openshift_metrics_cassandra_storage_type=dynamic
openshift_metrics_storage_volume_size=20Gi
openshift_metrics_hawkular_nodeselector={"node-role.kubernetes.io/infra": "true"}
openshift_metrics_cassandra_nodeselector={"node-role.kubernetes.io/infra": "true"}
openshift_metrics_heapster_nodeselector={"node-role.kubernetes.io/infra": "true"}

# logging
openshift_logging_install_logging=true
openshift_logging_es_pvc_dynamic=true
openshift_logging_storage_volume_size=50Gi
openshift_logging_kibana_nodeselector={"node-role.kubernetes.io/infra": "true"}
openshift_logging_curator_nodeselector={"node-role.kubernetes.io/infra": "true"}
openshift_logging_es_nodeselector={"node-role.kubernetes.io/infra": "true"}

# Setup azure blob registry storage
openshift_hosted_registry_storage_kind=object
openshift_hosted_registry_storage_azure_blob_accountkey=uZdkVlbca6xzwBqK8VDz15/loLUoc8I6cPfP31ZS+QOSxL6ylWT6CLrcadSqvtNTMgztxH4CGjYfVnRNUhvMiA==
openshift_hosted_registry_storage_provider=azure_blob
openshift_hosted_registry_storage_azure_blob_accountname=registry
openshift_hosted_registry_storage_azure_blob_container=registry
openshift_hosted_registry_storage_azure_blob_realm=core.windows.net

[masters]
ocp-master-1
ocp-master-2
ocp-master-3

[etcd]
ocp-master-1
ocp-master-2
ocp-master-3

[nodes]
ocp-master-1 openshift_node_group_name="node-config-master"
ocp-master-2 openshift_node_group_name="node-config-master"
ocp-master-3 openshift_node_group_name="node-config-master"
ocp-infra-1 openshift_node_group_name="node-config-infra"
ocp-infra-2 openshift_node_group_name="node-config-infra"
ocp-infra-3 openshift_node_group_name="node-config-infra"
ocp-app-1 openshift_node_group_name="node-config-compute"
1 2
If you use a container registry that requires authentication, such as the default container image registry, specify the credentials for that account. See Accessing and Configuring the Red Hat Registry.

24.4. Configuring OpenShift Container Platform for Microsoft Azure

You can configure OpenShift Container Platform for Microsoft Azure in two ways:

24.4.1. Configuring OpenShift Container Platform for Azure by using Ansible

You can configure OpenShift Container Platform for Azure at installation time.

Add the following to the Ansible inventory file located at /etc/ansible/hosts by default to configure your OpenShift Container Platform environment for Microsoft Azure:

[OSEv3:vars]
openshift_cloudprovider_kind=azure
openshift_cloudprovider_azure_client_id=<app_ID> 1
openshift_cloudprovider_azure_client_secret=<secret> 2
openshift_cloudprovider_azure_tenant_id=<tenant_ID> 3
openshift_cloudprovider_azure_subscription_id=<subscription> 4
openshift_cloudprovider_azure_resource_group=<resource_group> 5
openshift_cloudprovider_azure_location=<location> 6
1
The app ID value for the service principal.
2
The secret containing the password for the service principal.
3
The tenant in which the service principal exists.
4
The subscription used by the service principal.
5
The resource group where the service account exists.
6
The Microsoft Azure location where the resource group exists.

Installing with Ansible also creates and configures the following files to fit your Microsoft Azure environment:

  • /etc/origin/cloudprovider/azure.conf
  • /etc/origin/master/master-config.yaml
  • /etc/origin/node/node-config.yaml

24.4.2. Manually configuring OpenShift Container Platform for Microsoft Azure

24.4.2.1. Manually configuring master hosts for Microsoft Azure

Perform the following on all master hosts.

Procedure

  1. Edit the master configuration file located at /etc/origin/master/master-config.yaml by default on all masters and update the contents of the apiServerArguments and controllerArguments sections:

    kubernetesMasterConfig:
      ...
      apiServerArguments:
        cloud-provider:
          - "azure"
        cloud-config:
          - "/etc/origin/cloudprovider/azure.conf"
      controllerArguments:
        cloud-provider:
          - "azure"
        cloud-config:
          - "/etc/origin/cloudprovider/azure.conf"
    Important

    When triggering a containerized installation, only the /etc/origin and /var/lib/origin directories are mounted to the master and node container. Therefore, ensure master-config.yaml is in the /etc/origin/master directory instead of /etc/.

  2. When you configure OpenShift Container Platform for Microsoft Azure using Ansible, the /etc/origin/cloudprovider/azure.conf file is created automatically. Because you are manually configuring OpenShift Container Platform for Microsoft Azure, you must create the file on all node instances and include the following:

    tenantId: <tenant_ID> 1
    subscriptionId: <subscription> 2
    aadClientId: <app_ID> 3
    aadClientSecret: <secret> 4
    aadTenantId: <tenant_ID> 5
    resourceGroup: <resource_group> 6
    location: <location> 7
    1
    The tenant in which the service principal exists.
    2
    The subscription used by the service principal.
    3
    The appID value for the service principal.
    4
    The secret containing the password for the service principal.
    5
    The tenant in which the service principal exists.
    6
    The resource group where the service account exists.
    7
    The Microsoft Azure location where the resource group exists.
  3. Restart the OpenShift Container Platform master services:

    # master-restart api
    # master-restart controllers

24.4.2.2. Manually configuring node hosts for Microsoft Azure

Perform the following on all node hosts.

Procedure

  1. Edit the appropriate node configuration map and update the contents of the kubeletArguments section:

    kubeletArguments:
      cloud-provider:
        - "azure"
      cloud-config:
        - "/etc/origin/cloudprovider/azure.conf"
    Important

    The NIC used for accessing the instance must have an internal DNS name set or the node will not be able to rejoin the cluster, display build logs to the console, and will cause oc rsh to not work correctly.

  2. Restart the OpenShift Container Platform services on all nodes:

    # systemctl restart atomic-openshift-node

24.4.3. Configuring the OpenShift Container Platform registry for Microsoft Azure

Microsoft Azure provides object cloud storage that OpenShift Container Platform can use to store container images using the OpenShift Container Platform container image registry.

For more information, see Cloud Storage in the Azure documentation.

You can configure the registry either using Ansible or manually by configuring the registry configuration file.

Prerequisites

You must create a storage account to host the registry images before installation. The following command creates a storage account which is used during installation for image storage:

You can use Microsoft Azure blob storage for storing container images. The OpenShift Container Platform registry uses blob storage to allow for the registry to grow dynamically in size without the need for intervention from an administrator.

  1. Create an Azure storage account:

    az storage account create
    --name <account_name> \
    --resource-group <resource_group> \
    --location <location> \
    --sku Standard_LRS

    This creates an account key. To view the account key:

    az storage account keys list \
        --account-name <account-name> \
        --resource-group <resource-group> \
        --output table
    
    KeyName    Permissions    Value
    key1       Full           <account-key>
    key2       Full           <extra-account-key>

Only one account key value is required for the configuration of the OpenShift Container Platform registry.

Option 1: Configuring the OpenShift Container Platform registry for Azure using Ansible

Procedure

  1. Configure the Ansible inventory for the registry to use the storage account:

    [OSEv3:vars]
    # Azure Registry Configuration
    openshift_hosted_registry_replicas=1 1
    openshift_hosted_registry_storage_kind=object
    openshift_hosted_registry_storage_azure_blob_accountkey=<account_key> 2
    openshift_hosted_registry_storage_provider=azure_blob
    openshift_hosted_registry_storage_azure_blob_accountname=<account_name> 3
    openshift_hosted_registry_storage_azure_blob_container=<registry> 4
    openshift_hosted_registry_storage_azure_blob_realm=core.windows.net
    1
    The number of replicas to configure.
    2
    The account key associated with the <account-name>.
    3
    The storage account name.
    4
    Directory used to store the data. registry by default

Option 2: Manually configuring OpenShift Container Platform registry for Microsoft Azure

To use Microsoft Azure object storage, edit the registry’s configuration file and mount to the registry pod.

Procedure

  1. Export the current config.yml:

    $ oc get secret registry-config \
        -o jsonpath='{.data.config\.yml}' -n default | base64 -d \
      >> config.yml.old
  2. Create a new configuration file from the old config.yml:

    $ cp config.yml.old config.yml
  3. Edit the file to include the Azure parameters:

    storage:
      delete:
        enabled: true
      cache:
        blobdescriptor: inmemory
      azure:
        accountname: <account-name> 1
        accountkey: <account-key> 2
        container: registry 3
        realm: core.windows.net 4
    1
    Replace with the storage account name.
    2
    The account key associated to the <account-name>.
    3
    Directory used to store the data. registry by default
    4
    Storage realm core.windows.net by default
  4. Delete the registry-config secret:

    $ oc delete secret registry-config -n default
  5. Recreate the secret to reference the updated configuration file:

    $ oc create secret generic registry-config \
        --from-file=config.yml -n default
  6. Redeploy the registry to read the updated configuration:

    $ oc rollout latest docker-registry -n default

Verifying the registry is using blob object storage

To verify if the registry is using Microsoft Azure blob storage:

Procedure

  1. After a successful registry deployment, the registry deploymentconfig will always show that the registry is using an emptydir instead of Microsoft Azure blob storage:

    $ oc describe dc docker-registry -n default
    ...
    Mounts:
      ...
      /registry from registry-storage (rw)
    Volumes:
    registry-storage:
    Type:       EmptyDir 1
    ...
    1
    The temporary directory that shares a pod’s lifetime.
  2. Check if the /registry mount point is empty. This is the volume Microsoft Azure storage will use:

    $ oc exec \
        $(oc get pod -l deploymentconfig=docker-registry \
        -o=jsonpath='{.items[0].metadata.name}')  -i -t -- ls -l /registry
    total 0
  3. If it is empty, it is because the Microsoft Azure blob configuration is performed in the registry-config secret:

    $ oc describe secret registry-config
    Name:         registry-config
    Namespace:    default
    Labels:       <none>
    Annotations:  <none>
    
    Type:  Opaque
    
    Data
    ====
    config.yml:  398 bytes
  4. The installer creates a config.yml file with the desired configuration using the extended registry capabilities as seen in Storage in the installation documentation. To view the configuration file, including the storage section where the storage bucket configuration is stored:

    $ oc exec \
        $(oc get pod -l deploymentconfig=docker-registry \
          -o=jsonpath='{.items[0].metadata.name}') \
      cat /etc/registry/config.yml
    
      version: 0.1
      log:
        level: debug
      http:
        addr: :5000
      storage:
        delete:
          enabled: true
        cache:
          blobdescriptor: inmemory
        azure:
          accountname: registry
          accountkey: uZekVBJBa6xzwAqK8EDz15/hoHUoc8I6cPfP31ZS+QOSxLfo7WT7CLrVPKaqvtNTMgztxH7CGjYfpFRNUhvMiA==
          container: registry
          realm: core.windows.net
      auth:
        openshift:
          realm: openshift
      middleware:
        registry:
        - name: openshift
        repository:
        - name: openshift
          options:
            pullthrough: True
            acceptschema2: True
            enforcequota: False
        storage:
        - name: openshift

    Or you can view the secret:

    $ oc get secret registry-config -o jsonpath='{.data.config\.yml}' | base64 -d
    version: 0.1
    log:
      level: debug
    http:
      addr: :5000
    storage:
      delete:
        enabled: true
      cache:
        blobdescriptor: inmemory
      azure:
        accountname: registry
        accountkey: uZekVBJBa6xzwAqK8EDz15/hoHUoc8I6cPfP31ZS+QOSxLfo7WT7CLrVPKaqvtNTMgztxH7CGjYfpFRNUhvMiA==
        container: registry
        realm: core.windows.net
    auth:
      openshift:
        realm: openshift
    middleware:
      registry:
      - name: openshift
      repository:
      - name: openshift
        options:
          pullthrough: True
          acceptschema2: True
          enforcequota: False
      storage:
      - name: openshift

If using an emptyDir volume, the /registry mountpoint looks like the following:

$ oc exec \
    $(oc get pod -l deploymentconfig=docker-registry \
    -o=jsonpath='{.items[0].metadata.name}')  -i -t -- df -h /registry
Filesystem      Size  Used Avail Use% Mounted on
/dev/sdc         30G  226M   30G   1% /registry


$ oc exec \
    $(oc get pod -l deploymentconfig=docker-registry \
    -o=jsonpath='{.items[0].metadata.name}')  -i -t -- ls -l /registry
total 0
drwxr-sr-x. 3 1000000000 1000000000 22 Jun 19 12:24 docker

24.4.4. Configuring OpenShift Container Platform to use Microsoft Azure storage

OpenShift Container Platform can use Microsoft Azure storage using persistent volumes mechanisms. OpenShift Container Platform creates the disk in the resource group and attaches the disk to the correct instance.

Procedure

  1. The following storageclass is created when you configure the Azure cloud provider at installation using the openshift_cloudprovider_kind=azure and openshift_cloud_provider_azure variables in the Ansible inventory:

    $ oc get --export storageclass azure-standard -o yaml
    apiVersion: storage.k8s.io/v1
    kind: StorageClass
    metadata:
      annotations:
        storageclass.kubernetes.io/is-default-class: "true"
      creationTimestamp: null
      name: azure-standard
    parameters:
      kind: Shared
      storageaccounttype: Standard_LRS
    provisioner: kubernetes.io/azure-disk
    reclaimPolicy: Delete
    volumeBindingMode: Immediate

    If you did not use Ansible to enable OpenShift Container Platform and Microsoft Azure integration, you can create the storageclass manually. See the Dynamic provisioning and creating storage classes section for more information.

  2. Currently, the default storageclass kind is shared which means that the Microsoft Azure instances must use unmanaged disks. You can optionally modify this by allowing instances to use managed disks by providing the openshift_storageclass_parameters={'kind': 'Managed', 'storageaccounttype': 'Premium_LRS'} or openshift_storageclass_parameters={'kind': 'Managed', 'storageaccounttype': 'Standard_LRS'} variables in the Ansible inventory file at installation.
Note

Microsoft Azure disks are ReadWriteOnce access mode, which means the volume can be mounted as read-write by a single node. See the Access modes section of the Architecture guide for more information.

24.4.5. About Red Hat OpenShift Container Storage

Red Hat OpenShift Container Storage (RHOCS) is a provider of agnostic persistent storage for OpenShift Container Platform either in-house or in hybrid clouds. As a Red Hat storage solution, RHOCS is completely integrated with OpenShift Container Platform for deployment, management, and monitoring regardless if it is installed on OpenShift Container Platform (converged) or with OpenShift Container Platform (independent). OpenShift Container Storage is not limited to a single availability zone or node, which makes it likely to survive an outage. You can find complete instructions for using RHOCS in the RHOCS3.11 Deployment Guide.

24.5. Using the Microsoft Azure external load balancer as a service

OpenShift Container Platform can leverage the Microsoft Azure load balancer by exposing services externally using a LoadBalancer service. OpenShift Container Platform creates the load balancer in Microsoft Azure and creates the proper firewall rules.

Important

Currently, a bug causes extra variables to be included in the Microsoft Azure infrastructure when using it as a cloud provider and when using it as an external load balancer. See the following for more information:

Prerequisites

Ensure the the Azure configuration file located at /etc/origin/cloudprovider/azure.conf is correctly configured with the appropriate objects. See the Manually configuring OpenShift Container Platform for Microsoft Azure section for an example /etc/origin/cloudprovider/azure.conf file.

Once the values are added, restart the OpenShift Container Platform services on all hosts:

# systemctl restart atomic-openshift-node
# master-restart api
# master-restart controllers

24.5.1. Deploying a sample application using a load balancer

Procedure

  1. Create a new application:

    $ oc new-app openshift/hello-openshift
  2. Expose the load balancer service:

    $ oc expose dc hello-openshift --name='hello-openshift-external' --type='LoadBalancer'

    This creates a Loadbalancer service similar to the following:

    apiVersion: v1
    kind: Service
    metadata:
      labels:
        app: hello-openshift
      name: hello-openshift-external
    spec:
      externalTrafficPolicy: Cluster
      ports:
      - name: port-1
        nodePort: 30714
        port: 8080
        protocol: TCP
        targetPort: 8080
      - name: port-2
        nodePort: 30122
        port: 8888
        protocol: TCP
        targetPort: 8888
      selector:
        app: hello-openshift
        deploymentconfig: hello-openshift
      sessionAffinity: None
      type: LoadBalancer
  3. Verify that the service has been created:

    $ oc get svc
    NAME                       TYPE           CLUSTER-IP       EXTERNAL-IP     PORT(S)                         AGE
    hello-openshift            ClusterIP      172.30.223.255   <none>          8080/TCP,8888/TCP               1m
    hello-openshift-external   LoadBalancer   172.30.99.54     40.121.42.180   8080:30714/TCP,8888:30122/TCP   4m

    The LoadBalancer type and External-IP fields indicate that the service is using Microsoft Azure load balancers to expose the application.

This creates the following required objects in the Azure infrastructure:

  • A load balancer:

    az network lb list -o table
    Location    Name         ProvisioningState    ResourceGroup    ResourceGuid
    ----------  -----------  -------------------  ---------------  ------------------------------------
    eastus      kubernetes   Succeeded            refarch-azr      30ec1980-b7f5-407e-aa4f-e570f06f168d
    eastus      OcpMasterLB  Succeeded            refarch-azr      acb537b2-8a1a-45d2-aae1-ea9eabfaea4a
    eastus      OcpRouterLB  Succeeded            refarch-azr      39087c4c-a5dc-457e-a5e6-b25359244422

To verify that the load balancer is properly configured, run the following from an external host:

$ curl 40.121.42.180:8080 1
Hello OpenShift!
1
Replace with the values from the EXTERNAL-IP verification step above as well as the port number.
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