Chapter 1. Managing applications

Channels (channel.apps.open-cluster-management.io) define the source repositories that a cluster can subscribe to with a subscription, and can be the following types: Git, Helm release, and Object storage repositories, and resource templates on the hub cluster.

If you have applications that require Kubernetes resources or Helm charts from channels that require authorization, such as entitled Git repositories, you can use secrets to provide access to these channels. Your subscriptions can access Kubernetes resources and Helm charts for deployment from these channels, while maintaining data security.

Channels use a namespace within the hub cluster and point to a physical place where resources are stored for deployment. Clusters can subscribe to channels for identifying the resources to deploy to each cluster.

Notes: It is best practice to create each channel in a unique namespace. However, a Git channel can share a namespace with another type of channel, including Git, Helm, and Object storage.

Resources within a channel can be accessed by only the clusters that subscribe to that channel.

When creating subscriptions using a Git repository, you can add a do-not-delete annotation to keep specific deployed resources after you delete the subscription. The do-not-delete annotation only works with top-level deployment resources. To add the do-not-delete annotation, complete the following steps:

After deleting the subscription, the resources with the do-not-delete annotation still exist, while other resources are deleted.

Note: The resources that remain deployed by using the do-not-delete annotation bind to the namespace. As a result, you cannot delete the namespace until you remove the remaining resources.

The following example channel definition abstracts a Helm repository as a channel:

Note: For Helm, all Kubernetes resources contained within the Helm chart must have the label release. {{ .Release.Name }}` for the application topology to be displayed properly.

apiVersion: v1
kind: Namespace
metadata:
  name: hub-repo
---
apiVersion: apps.open-cluster-management.io/v1
kind: Channel
metadata:
  name: helm
  namespace: hub-repo
spec:
    pathname: [https://kubernetes-charts.storage.googleapis.com/] # URL points to a valid chart URL.
    type: HelmRepo

The following channel definition shows another example of a Helm repository channel:

apiVersion: apps.open-cluster-management.io/v1
kind: Channel
metadata:
  name: predev-ch
  namespace: ns-ch
  labels:
    app: nginx-app-details
spec:
  type: HelmRepo
  pathname: https://kubernetes-charts.storage.googleapis.com/

Note: To see REST APIs, use the APIs.

Helm provides an annotation to keep specific deployed resources after you delete a subscription. See Tell Helm Not To Uninstall a Resource for more information.

Note: The annotation must be in the Helm chart.

The following example channel definition abstracts an object storage as a channel:

apiVersion: apps.open-cluster-management.io/v1
kind: Channel
metadata:
 name: dev
 namespace: ch-obj
spec:
 type: Object storage
 pathname: [http://sample-ip:#####/dev] # URL is appended with the valid bucket name, which matches the channel name.
 secretRef:
   name: miniosecret
 gates:
   annotations:
     dev-ready: true

Note: To see REST API, use the APIs.

You can set up subscriptions to subscribe resources that are defined in the Amazon Simple Storage Service (Amazon S3) object storage service. See the following procedure:

See the following complete AWS S3 object bucket channel sample YAML file:

apiVersion: apps.open-cluster-management.io/v1
kind: Channel
metadata:
  name: object-dev
  namespace: ch-object-dev
spec:
  type: ObjectBucket
  pathname: https://s3.console.aws.amazon.com/s3/buckets/sample-bucket-1
  secretRef:
    name: secret-dev
---
apiVersion: v1
kind: Secret
metadata:
  name: secret-dev
  namespace: ch-object-dev
stringData:
  AccessKeyID: <your AWS bucket access key id>
  SecretAccessKey: <your AWS bucket secret access key>
  Region: <your AWS  bucket region>
type: Opaque

Deprecated: You can continue to create other AWS subscription and placement rule objects, as you see in the following sample YAML with kind: PlacementRule and kind: Subscription added:

apiVersion: apps.open-cluster-management.io/v1
kind: PlacementRule
metadata:
  name: towhichcluster
  namespace: obj-sub-ns
spec:
  clusterSelector: {}
---
apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: obj-sub
  namespace: obj-sub-ns
spec:
  channel: ch-object-dev/object-dev
  placement:
    placementRef:
      kind: PlacementRule
      name: towhichcluster

You can also subscribe to objects within a specific subfolder in the object bucket. Add the subfolder annotation to the subscription, which forces the object bucket subscription to only apply all the resources in the subfolder path.

See the annotation with subfolder-1 as the bucket-path:

annotations:
  apps.open-cluster-management.io/bucket-path: <subfolder-1>

See the following complete sample for a subfolder:

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  annotations:
    apps.open-cluster-management.io/bucket-path: subfolder1
  name: obj-sub
  namespace: obj-sub-ns
  labels:
    name: obj-sub
spec:
  channel: ch-object-dev/object-dev
  placement:
    placementRef:
      kind: PlacementRule
      name: towhichcluster

When creating subscriptions using an Object storage repository, you can add a do-not-delete annotation to keep specific deployed resources after you delete the subscription. The do-not-delete annotation only works with top-level deployment resources. To add the do-not-delete annotation, complete the following steps:

After deleting the subscription, the resources with the do-not-delete annotation still exist, while other resources are deleted.

Note: The resources that remain deployed by using the do-not-delete annotation bind to the namespace. As a result, you cannot delete the namespace until you remove the remaining resources.

The application subscription controller searches all the kind:AnsibleJob CRs in the prehook folder as the prehook AnsibleJob objects, then generates a new prehook AnsibleJob instance. The new instance name is the prehook AnsibleJob object name and a random suffix string.

See the following example instance name: database-sync-1-2913063.

The application subscription controller queues the reconcile request again in a one minute loop, where it checks the prehook AnsibleJob status.AnsibleJobResult. When the prehook status is successful, the application subscription continues to deploy the main subscription.

When the application subscription status is updated, if the subscription status is subscribed or propagated to all target clusters in subscribed status, the application subscription controller searches all of the AnsibleJob kind custom resources in the posthook folder as the posthook AnsibleJob objects. Then, it generates new posthook AnsibleJob instances. The new instance name is the posthook AnsibleJob object name and a random suffix string.

See the following example instance name: service-ticket-1-2913849.

See the following topics to enable Ansible Automation Platform:

You can then create the credential from the Credentials page in the console. Click Add credential, or access the page from the navigation. See Creating a credential for Ansible Automation Platform for credential information.

You must create an Ansible Automation Platform secret custom resources in the same subscription namespace. The Ansible Automation Platform secret is limited to the same subscription namespace.

When the app subscription controller creates prehook and posthook Ansible jobs, if the secret from subscription spec.hooksecretref is available, then it is sent to the AnsibleJob custom resources spec.tower_auth_secret and the AnsibleJob can access the Ansible Automation Platform.

For a main-sub subscription with prehook and posthook AnsibleJob, the main-sub subscription should be reconciled after all prehook and posthook AnsibleJob or main subscription are updated in the Git repository.

Prehook AnsibleJob and the main subscription continuously reconcile and relaunch a new pre AnsibleJob instance.

When an AnsibleJob custom resources is created, A Kubernetes job custom resources is created to launch an Ansible Automation Platform job by communicating to the target Ansible Automation Platform. When the job is complete, the final status for the job is returned to AnsibleJob status.AnsibleJob Result.

Notes:

The AnsibleJob status.conditions is reserved by the Ansible Automation Platform Job operator for storing the creation of Kubernetes job result. The status.conditions does not reflect the actual Ansible Automation Platform job status.

The subscription controller checks the Ansible Automation Platform job status by the AnsibleJob.status.AnsibleJob.Result instead of AnsibleJob.status.conditions.

As previously mentioned in the prehook and posthook AnsibleJob workflow, when the main subscription is updated in Git repository, a new prehook and posthook AnsibleJob instance is created. As a result, one main subscription can link to multiple AnsibleJob instances.

Four fields are defined in subscription.status.ansiblejobs:

See the following sample of an AnsibleJob YAML file in a Git prehook and posthook folder:

apiVersion: tower.ansible.com/v1alpha1
kind: AnsibleJob
metadata:
  name: demo-job-001
  namespace: default
spec:
  tower_auth_secret: toweraccess
  job_template_name: Demo Job Template
  extra_vars:
    cost: 6.88
    ghosts: ["inky","pinky","clyde","sue"]
    is_enable: false
    other_variable: foo
    pacman: mrs
    size: 8
    targets_list:
    - aaa
    - bbb
    - ccc
    version: 1.23.45
  job_tags: "provision,install,configuration"
  skip_tags: "configuration,restart"

To launch an Ansible Automation Platform Workflow by using the AnsibleJob custom resource, replace the job_template_name field with the workflow_template_name, which is displayed in the following example.

See the following sample of a Workflow AnsibleJob YAML file in a Git prehook and Git posthook folder:

apiVersion: tower.ansible.com/v1alpha1
kind: AnsibleJob
metadata:
  name: demo-job-001
  namespace: default
spec:
  tower_auth_secret: toweraccess
  workflow_template_name: Demo Workflow Template
  extra_vars:
    cost: 6.88
    ghosts: ["inky","pinky","clyde","sue"]
    is_enable: false
    other_variable: foo
    pacman: mrs
    size: 8
    targets_list:
    - aaa
    - bbb
    - ccc
    version: 1.23.45

See Workflows to learn more about Ansible Workflow.

You need to specify the full group and version for apiVersion in resource YAML when you subscribe. For example, if you subscribe to apiVersion: v1, the subscription controller fails to validate the subscription and you receive an error: Resource /v1, Kind=ImageStream is not supported.

If the apiVersion is changed to image.openshift.io/v1, as in the following sample, it passes the validation in the subscription controller and the resource is applied successfully.

apiVersion: `image.openshift.io/v1`
kind: ImageStream
metadata:
  name: default
  namespace: default
spec:
  lookupPolicy:
    local: true
  tags:
    - name: 'latest'
      from:
        kind: DockerImage
        name: 'quay.io/repository/open-cluster-management/multicluster-operators-subscription:community-latest'

Next, see more useful examples of how a subscription administrator can change default behavior.

In this following examples, you are logged in as a subscription administrator.

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: subscription-example
  namespace: subscription-ns
  annotations:
    apps.open-cluster-management.io/git-path: sample-resources
    apps.open-cluster-management.io/reconcile-option: merge
    apps.open-cluster-management.io/current-namespace-scoped: "true"
spec:
  channel: channel-ns/somechannel
  placement:
    placementRef:
      name: dev-clusters

Applicable channel types: Git, ObjectBucket (Object storage in the console)

Note: The resource overwrite option is not applicable to helm charts from the Git repository because the helm chart resources are managed by Helm.

In this example, the following ConfigMap already exists in the target cluster.

apiVersion: v1
kind: ConfigMap
metadata:
  name: test-configmap-1
  namespace: sub-ns
data:
  name: user1
  age: 19

Subscribe the following sample resource YAML file from a Git repository and replace the existing ConfigMap. See the change in the data specification:

apiVersion: v1
kind: ConfigMap
metadata:
  name: test-configmap-1
  namespace: sub-ns
data:
  age: 20

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: subscription-example
  namespace: sub-ns
  annotations:
    apps.open-cluster-management.io/git-path: sample-resources
    apps.open-cluster-management.io/reconcile-option: merge
spec:
  channel: channel-ns/somechannel
  placement:
    placementRef:
      name: dev-clusters

apiVersion: v1
kind: ConfigMap
metadata:
  name: test-configmap-1
  namespace: sub-ns
data:
  name: user1
  age: 20

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: subscription-example
  namespace: sub-ns
  annotations:
    apps.open-cluster-management.io/git-path: sample-resources
    apps.open-cluster-management.io/reconcile-option: mergeAndOwn
spec:
  channel: channel-ns/somechannel
  placement:
    placementRef:
      name: dev-clusters

apiVersion: v1
kind: ConfigMap
metadata:
  name: test-configmap-1
  namespace: sub-ns
  annotations:
    apps.open-cluster-management.io/hosting-subscription: sub-ns/subscription-example
data:
  name: user1
  age: 20

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: subscription-example
  namespace: sub-ns
  annotations:
    apps.open-cluster-management.io/git-path: sample-resources
    apps.open-cluster-management.io/reconcile-option: replace
spec:
  channel: channel-ns/somechannel
  placement:
    placementRef:
      name: dev-clusters

apiVersion: v1
kind: ConfigMap
metadata:
  name: test-configmap-1
  namespace: sub-ns
data:
  age: 20

You can subscribe to a specific Git branch, commit, or tag.

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: git-mongodb-subscription
  annotations:
    apps.open-cluster-management.io/git-path: stable/ibm-mongodb-dev
    apps.open-cluster-management.io/git-branch: <branch1>

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: git-mongodb-subscription
  annotations:
    apps.open-cluster-management.io/git-path: stable/ibm-mongodb-dev
    apps.open-cluster-management.io/git-desired-commit: <full commit number>
    apps.open-cluster-management.io/git-clone-depth: 100

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: git-mongodb-subscription
  annotations:
    apps.open-cluster-management.io/git-path: stable/ibm-mongodb-dev
    apps.open-cluster-management.io/git-tag: <v1.0>
    apps.open-cluster-management.io/git-clone-depth: 100

You can select reconcile frequency options: high, medium, low, and off in channel configuration to avoid unnecessary resource reconciliations and therefore prevent overload on subscription operator.

Required access: Administrator and cluster administrator

See the following definitions of the settings:attribute:<value>:

You can set this by using the apps.open-cluster-management.io/reconcile-rate annotation in the channel custom resource that is referenced by subscription.

See the following name: git-channel example:

apiVersion: apps.open-cluster-management.io/v1
kind: Channel
metadata:
  name: git-channel
  namespace: sample
  annotations:
    apps.open-cluster-management.io/reconcile-rate: <value from the list>
spec:
  type: GitHub
  pathname: <Git URL>
---
apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: git-subscription
  annotations:
    apps.open-cluster-management.io/git-path: <application1>
    apps.open-cluster-management.io/git-branch: <branch1>
spec:
  channel: sample/git-channel
  placement:
    local: true

In the previous example, all subscriptions that use sample/git-channel are assigned low reconciliation frequency.

Regardless of the reconcile-rate setting in the channel, a subscription can turn the auto-reconciliation off by specifying apps.open-cluster-management.io/reconcile-rate: off annotation in the Subscription custom resource.

See the following git-channel example:

apiVersion: apps.open-cluster-management.io/v1
kind: Channel
metadata:
  name: git-channel
  namespace: sample
  annotations:
    apps.open-cluster-management.io/reconcile-rate: high
spec:
  type: GitHub
  pathname: <Git URL>
---
apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: git-subscription
  annotations:
    apps.open-cluster-management.io/git-path: application1
    apps.open-cluster-management.io/git-branch: branch1
    apps.open-cluster-management.io/reconcile-rate: "off"
spec:
  channel: sample/git-channel
  placement:
    local: true

See that the resources deployed by git-subscription are never automatically reconciled even if the reconcile-rate is set to high in the channel.

Every 15 minutes, the subscription operator compares currently deployed hash of your Helm chart to the hash from the source repository. Changes are applied to target clusters. The frequency of resource reconciliation impacts the performance of other application deployments and updates.

For example, if there are hundreds of application subscriptions and you want to reconcile all subscriptions more frequently, the response time of reconciliation is slower.

Depending on the Kubernetes resources of the application, appropriate reconciliation frequency can improve performance.

You can set this using apps.open-cluster-management.io/reconcile-rate annotation in the Channel custom resource that is referenced by subscription. See the following helm-channel example:

See the following helm-channel example:

apiVersion: apps.open-cluster-management.io/v1
kind: Channel
metadata:
  name: helm-channel
  namespace: sample
  annotations:
    apps.open-cluster-management.io/reconcile-rate: low
spec:
  type: HelmRepo
  pathname: <Helm repo URL>
---
apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: helm-subscription
spec:
  channel: sample/helm-channel
  name: nginx-ingress
  packageOverrides:
  - packageName: nginx-ingress
    packageAlias: nginx-ingress-simple
    packageOverrides:
    - path: spec
      value:
        defaultBackend:
          replicaCount: 3
  placement:
    local: true

In this example, all subscriptions that uses sample/helm-channel are assigned a low reconciliation frequency.

Regardless of the reconcile-rate setting in the channel, a subscription can turn the auto-reconciliation off by specifying apps.open-cluster-management.io/reconcile-rate: off annotation in the Subscription custom resource, as displayed in the following example:

apiVersion: apps.open-cluster-management.io/v1
kind: Channel
metadata:
  name: helm-channel
  namespace: sample
  annotations:
    apps.open-cluster-management.io/reconcile-rate: high
spec:
  type: HelmRepo
  pathname: <Helm repo URL>
---
apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: helm-subscription
  annotations:
    apps.open-cluster-management.io/reconcile-rate: "off"
spec:
  channel: sample/helm-channel
  name: nginx-ingress
  packageOverrides:
  - packageName: nginx-ingress
    packageAlias: nginx-ingress-simple
    packageOverrides:
    - path: spec
      value:
        defaultBackend:
          replicaCount: 3
  placement:
    local: true

In this example, the resources deployed by helm-subscription are never automatically reconciled, even if the reconcile-rate is set to high in the channel.

To configure LeaderElection, you change the following default values:

See the following steps to change the multicluster-operators-application, multicluster-operators-channel, multicluster-operators-standalone-subscription, or multicluster-operators-hub-subscription controllers:

oc annotate mch -n open-cluster-management multiclusterhub mch-pause=false --overwrite=true

See the following example output of a successful edit to the -command, where the retryPeriod flag doubles the previously mentioned default time to 52, which is allotted to retry acquiring leaderElection:

command:
- /usr/local/bin/multicluster-operators-subscription
- --sync-interval=60
- --retry-period=52

You can connect to a Git server using channel and subscription. See the following procedures for connecting to a private repository with a user and access token:

You can use the following connection method in a development environment to connect to a privately-hosted Git server with SSL certificates that are signed by custom or self-signed certificate authority. However, this procedure is not recommended for production:

Specify insecureSkipVerify: true in the channel specification. Otherwise, the connection to the Git server fails with an error similar to the following:

x509: certificate is valid for localhost.com, not localhost

See the following sample with the channel specification addition for this method:

apiVersion: apps.open-cluster-management.io/v1
kind: Channel
metadata:
labels:
  name: sample-channel
  namespace: sample
spec:
  type: GitHub
  pathname: <Git HTTPS URL>
  insecureSkipVerify: true

You can use this connection method to securely connect to a privately-hosted Git server with SSL certificates that are signed by custom or self-signed certificate authority.

If a Git channel connection configuration requires an update, such as CA certificates, credentials, or SSH key, you need to create a new secret and ConfigMap in the same namespace and update the channel to reference that new secret and ConfigMap. For more information, see Using custom CA certificates for a secure HTTPS connection.

Required access: Cluster administrator

To configure the Helm application to watch namespace scoped resources, set the value for the watchHelmNamespaceScopedResources field in your subscription definition to true. See the following sample.

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: nginx
  namespace: ns-sub-1
spec:
  watchHelmNamespaceScopedResources: true
  channel: ns-ch/predev-ch
  name: nginx-ingress
  packageFilter:
    version: "1.36.x"

For application samples that you can deploy, see the stolostron repository.

The following YAML structures show the required fields for a channel and some of the common optional fields. Your YAML structure needs to include some required fields and values. Depending on your application management requirements, you might need to include other optional fields and values. You can compose your own YAML content with any tool and in the product console.

apiVersion: apps.open-cluster-management.io/v1
kind: Channel
metadata:
  name:
  namespace: # Each channel needs a unique namespace, except Git channel.
spec:
  sourceNamespaces:
  type:
  pathname:
  secretRef:
    name:
  gates:
    annotations:
  labels:

The definition structure for a channel can resemble the following YAML content:

apiVersion: apps.open-cluster-management.io/v1
kind: Channel
metadata:
  name: predev-ch
  namespace: ns-ch
  labels:
    app: nginx-app-details
spec:
  type: HelmRepo
  pathname: https://kubernetes-charts.storage.googleapis.com/

The following example channel definition abstracts an Object storage bucket as a channel:

apiVersion: apps.open-cluster-management.io/v1
kind: Channel
metadata:
 name: dev
 namespace: ch-obj
spec:
 type: ObjectBucket
 pathname: [http://9.28.236.243:xxxx/dev] # URL is appended with the valid bucket name, which matches the channel name.
 secretRef:
   name: miniosecret
 gates:
   annotations:
     dev-ready: true

The following example channel definition abstracts a Helm repository as a channel:

Deprecation notice: For 2.12, specifying insecureSkipVerify: "true" in channel ConfigMap reference to skip Helm repo SSL certificate is deprecated. See the replacement in the following current sample, with spec.insecureSkipVerify: true that is used in the channel instead:

apiVersion: v1
kind: Namespace
metadata:
  name: hub-repo
---
apiVersion: apps.open-cluster-management.io/v1
kind: Channel
metadata:
  name: Helm
  namespace: hub-repo
spec:
    pathname: [https://9.21.107.150:8443/helm-repo/charts] # URL points to a valid chart URL.
    insecureSkipVerify: true
    type: HelmRepo

The following channel definition shows another example of a Helm repository channel:

Note: For Helm, all Kubernetes resources contained within the Helm chart must have the label release {{ .Release.Name }} for the application topology to display properly.

apiVersion: apps.open-cluster-management.io/v1
kind: Channel
metadata:
  name: predev-ch
  namespace: ns-ch
  labels:
    app: nginx-app-details
spec:
  type: HelmRepo
  pathname: https://kubernetes-charts.storage.googleapis.com/

The following example channel definition displays an example of a channel for the Git Repository. In the following example, secretRef refers to the user identity that is used to access the Git repo that is specified in the pathname. If you have a public repo, you do not need the secretRef label and value:

apiVersion: apps.open-cluster-management.io/v1
kind: Channel
metadata:
  name: hive-cluster-gitrepo
  namespace: gitops-cluster-lifecycle
spec:
  type: Git
  pathname: https://github.com/open-cluster-management/gitops-clusters.git
  secretRef:
    name: github-gitops-clusters
---
apiVersion: v1
kind: Secret
metadata:
  name: github-gitops-clusters
  namespace: gitops-cluster-lifecycle
data:
  user: dXNlcgo=            # Value of user and accessToken is Base 64 coded.
  accessToken: cGFzc3dvcmQ

The following YAML structure shows the required fields for a subscription and some of the common optional fields. Your YAML structure needs to include certain required fields and values.

Depending on your application management requirements, you might need to include other optional fields and values. You can compose your own YAML content with any tool:

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name:
  namespace:
  labels:
spec:
  sourceNamespace:
  source:
  channel:
  name:
  packageFilter:
    version:
    labelSelector:
      matchLabels:
        package:
        component:
    annotations:
  packageOverrides:
  - packageName:
    packageAlias:
    - path:
      value:
  placement:
    local:
    clusters:
      name:
    clusterSelector:
    placementRef:
      name:
      kind: Placement
  overrides:
    clusterName:
    clusterOverrides:
      path:
      value:

Notes:

Your subscription can resemble the following YAML content:

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: nginx
  namespace: ns-sub-1
  labels:
    app: nginx-app-details
spec:
  channel: ns-ch/predev-ch
  name: nginx-ingress
  packageFilter:
    version: "1.36.x"
  placement:
    placementRef:
      kind: Placement
      name: towhichcluster
  overrides:
  - clusterName: "/"
    clusterOverrides:
    - path: "metadata.namespace"
      value: default

For application samples that you can deploy, see the stolostron repository.

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: nginx
  namespace: ns-sub-1
  labels:
    app: nginx-app-details
spec:
  channel: ns-ch/predev-ch
  name: nginx-ingress

If there is a mirrored channel (application source repository), you can specify a secondaryChannel in the subscription YAML. When an application subscription fails to connect to the repository server using the primary channel, it connects to the repository server using the secondary channel. Ensure that the application manifests stored in the secondary channel are in sync with the primary channel. See the following sample subscription YAML with the secondaryChannel.

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: nginx
  namespace: ns-sub-1
  labels:
    app: nginx-app-details
spec:
  channel: ns-ch/predev-ch
  secondaryChannel: ns-ch-2/predev-ch-2
  name: nginx-ingress

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: nginx
  namespace: ns-sub-1
  labels:
    app: nginx-app-details
spec:
  channel: ns-ch/predev-ch
  name: nginx-ingress
  packageFilter:
    version: "1.36.x"
  placement:
    placementRef:
      kind: Placement
      name: towhichcluster
  timewindow:
    windowtype: "active"
    location: "America/Los_Angeles"
    daysofweek: ["Monday", "Wednesday", "Friday"]
    hours:
      - start: "10:20AM"
        end: "10:30AM"
      - start: "12:40PM"
        end: "1:40PM"

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: simple
  namespace: default
spec:
  channel: ns-ch/predev-ch
  name: nginx-ingress
  packageOverrides:
  - packageName: nginx-ingress
    packageAlias: my-nginx-ingress-releaseName
    packageOverrides:
    - path: spec
      value:
        defaultBackend:
          replicaCount: 3
  placement:
    local: false

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: nginx
  namespace: ns-sub-1
  labels:
    app: nginx-app-details
spec:
  channel: ns-ch/predev-ch
  name: nginx-ingress
  packageFilter:
    version: "1.36.x"
  placement:
    clusters:
    - name: my-development-cluster-1
  packageOverrides:
  - packageName: my-server-integration-prod
    packageOverrides:
    - path: spec
      value:
        persistence:
          enabled: false
          useDynamicProvisioning: false
        license: accept
        tls:
          hostname: my-mcm-cluster.icp
        sso:
          registrationImage:
            pullSecret: hub-repo-docker-secret

    apiVersion: apps.open-cluster-management.io/v1
    kind: Subscription
    metadata:
      name: sample-subscription
      namespace: default
      annotations:
        apps.open-cluster-management.io/git-path: sample_app_1/dir1
        apps.open-cluster-management.io/git-branch: branch1
    spec:
      channel: default/sample-channel
      placement:
        placementRef:
          kind: Placement
          name: dev-clusters

apiVersion: apps.open-cluster-management.io/v1
kind: Subscription
metadata:
  name: example-subscription
  namespace: default
spec:
  channel: some/channel
  packageOverrides:
  - packageName: kustomization
    packageOverrides:
    - value: |
patchesStrategicMerge:
- patch.yaml

oc create route passthrough --service=multicluster-operators-subscription -n open-cluster-management

apiVersion: v1
kind: Secret
metadata:
  name: my-github-webhook-secret
data:
  secret: BASE64_ENCODED_SECRET

oc annotate channel.apps.open-cluster-management.io <channel name> apps.open-cluster-management.io/webhook-enabled="true"

oc annotate channel.apps.open-cluster-management.io <channel name> apps.open-cluster-management.io/webhook-secret="<the_secret_name>"

The following YAML structure shows the required fields for a placement rule and some of the common optional fields. Your YAML structure needs to include some required fields and values. Depending on your application management requirements, you might need to include other optional fields and values. You can compose your own YAML content with any tool and in the product console

apiVersion: apps.open-cluster-management.io/v1
kind: PlacementRule
metadata:
  name:
  namespace:
  resourceVersion:
  labels:
    app:
    chart:
    release:
    heritage:
  selfLink:
  uid:
spec:
  clusterSelector:
    matchLabels:
      datacenter:
      environment:
  clusterReplicas:
  clusterConditions:
  ResourceHint:
    type:
    order:
  Policies:

For application samples that you can deploy, see the stolostron repository.

Existing placement rules can include the following fields that indicate the status for the placement rule. This status section is appended after the spec section in the YAML structure for a rule.

status:
  decisions:
    clusterName:
    clusterNamespace:

apiVersion: apps.open-cluster-management.io/v1
kind: PlacementRule
metadata:
  name: gbapp-gbapp
  namespace: development
  labels:
    app: gbapp
spec:
  clusterSelector:
    matchLabels:
      environment: Dev
  clusterReplicas: 1
status:
  decisions:
    - clusterName: local-cluster
      clusterNamespace: local-cluster

apiVersion: apps.open-cluster-management.io/v1
kind: PlacementRule
metadata:
  name: towhichcluster
  namespace: ns-sub-1
  labels:
    app: nginx-app-details
spec:
  clusterReplicas: 1
  clusterConditions:
    - type: ManagedClusterConditionAvailable
      status: "True"
  clusterSelector:
    matchExpressions:
    - key: environment
      operator: In
      values:
      - dev

To compose the application definition YAML content for creating or updating an application resource, your YAML structure needs to include some required fields and values. Depending on your application requirements or application management requirements, you might need to include other optional fields and values.

The following YAML structure shows the required fields for an application and some of the common optional fields.

apiVersion: app.k8s.io/v1beta1
kind: Application
metadata:
  name:
  namespace:
spec:
  selector:
    matchLabels:
      label_name: label_value

The spec for defining these applications is based on the Application metadata descriptor custom resource definition that is provided by the Kubernetes Special Interest Group (SIG). Only the values shown in the table are required.

You can use this definition to help you compose your own application YAML content. For more information about this definition, see Kubernetes SIG Application CRD community specification.

For application samples that you can deploy, see the stolostron repository.

The definition structure for an application can resemble the following example YAML content:

apiVersion: app.k8s.io/v1beta1
kind: Application
metadata:
  name: my-application
  namespace: my-namespace
spec:
  selector:
    matchLabels:
      my-label: my-label-value