Chapter 2. Planning a deployment of AMQ Broker on OpenShift Container Platform This section describes how to plan an Operator-based deployment. Operators are programs that enable you to package, deploy, and manage OpenShift applications. Often, Operators automate common or complex tasks. Commonly, Operators are intended to provide: Consistent, repeatable installations Health checks of system components Over-the-air (OTA) updates Managed upgrades Operators enable you to make changes while your broker instances are running, because they are always listening for changes to the Custom Resource (CR) instances that you used to configure your deployment. When you make changes to a CR, the Operator reconciles the changes with the existing broker deployment and updates the deployment to reflect the changes. In addition, the Operator provides a message migration capability, which ensures the integrity of messaging data. When a broker in a clustered deployment shuts down due to an intentional scaledown of the deployment, this capability migrates messages to a broker Pod that is still running in the same broker cluster. 2.1. Overview of the AMQ Broker Operator Custom Resource Definitions In general, a Custom Resource Definition (CRD) is a schema of configuration items that you can modify for a custom OpenShift object deployed with an Operator. By creating a corresponding Custom Resource (CR) instance, you can specify values for configuration items in the CRD. If you are an Operator developer, what you expose through a CRD essentially becomes the API for how a deployed object is configured and used. You can directly access the CRD through regular HTTP curl commands, because the CRD gets exposed automatically through Kubernetes. You can install the AMQ Broker Operator using either the OpenShift command-line interface (CLI), or the Operator Lifecycle Manager, through the OperatorHub graphical interface. In either case, the AMQ Broker Operator includes the CRDs described below. Main broker CRD You deploy a CR instance based on this CRD to create and configure a broker deployment. Based on how you install the Operator, this CRD is: The broker_activemqartemis_crd file in the crds directory of the Operator installation archive (OpenShift CLI installation method) The ActiveMQArtemis CRD in the Custom Resource Definitions section of the OpenShift Container Platform web console (OperatorHub installation method) Address CRD You deploy a CR instance based on this CRD to create addresses and queues for a broker deployment. Based on how you install the Operator, this CRD is: The broker_activemqartemisaddress_crd file in the crds directory of the Operator installation archive (OpenShift CLI installation method) The ActiveMQArtemisAddresss CRD in the Custom Resource Definitions section of the OpenShift Container Platform web console (OperatorHub installation method) Security CRD You deploy a CR instance based on this CRD to create users and associate those users with security contexts. Based on how you install the Operator, this CRD is: The broker_activemqartemissecurity_crd file in the crds directory of the Operator installation archive (OpenShift CLI installation method) The ActiveMQArtemisSecurity CRD in the Custom Resource Definitions section of the OpenShift Container Platform web console (OperatorHub installation method). Scaledown CRD The Operator automatically creates a CR instance based on this CRD when instantiating a scaledown controller for message migration. Based on how you install the Operator, this CRD is: The broker_activemqartemisscaledown_crd file in the crds directory of the Operator installation archive (OpenShift CLI installation method) The ActiveMQArtemisScaledown CRD in the Custom Resource Definitions section of the OpenShift Container Platform web console (OperatorHub installation method). Additional resources To learn how to install the AMQ Broker Operator (and all included CRDs) using: The OpenShift CLI, see Section 3.2, "Installing the Operator using the CLI" The Operator Lifecycle Manager and OperatorHub graphical interface, see Section 3.3, "Installing the Operator using OperatorHub" . For complete configuration references to use when creating CR instances based on the main broker and address CRDs, see: Section 8.1.1, "Broker Custom Resource configuration reference" Section 8.1.2, "Address Custom Resource configuration reference" 2.2. Overview of the AMQ Broker Operator sample Custom Resources The AMQ Broker Operator archive that you download and extract during installation includes sample Custom Resource (CR) files in the deploy/crs directory. These sample CR files enable you to: Deploy a minimal broker without SSL or clustering. Define addresses. The broker Operator archive that you download and extract also includes CRs for example deployments in the deploy/examples directory, as listed below. artemis-basic-deployment.yaml Basic broker deployment. artemis-persistence-deployment.yaml Broker deployment with persistent storage. artemis-cluster-deployment.yaml Deployment of clustered brokers. artemis-persistence-cluster-deployment.yaml Deployment of clustered brokers with persistent storage. artemis-ssl-deployment.yaml Broker deployment with SSL security. artemis-ssl-persistence-deployment.yaml Broker deployment with SSL security and persistent storage. artemis-aio-journal.yaml Use of asynchronous I/O (AIO) with the broker journal. address-queue-create.yaml Address and queue creation. 2.3. Watch options for a Cluster Operator deployment When the Cluster Operator is running, it starts to watch for updates of AMQ Broker custom resources (CRs). You can choose to deploy the Cluster Operator to watch CRs from: A single namespace (the same namespace containing the Operator) All namespaces Note If you have already installed a version of the AMQ Broker Operator in a namespace on your cluster, Red Hat recommends that you do not install the AMQ Broker Operator 7.10 version to watch that namespace to avoid potential conflicts. 2.4. How the Operator chooses container images When you create a Custom Resource (CR) instance for a broker deployment, you do not need to explicitly specify broker or Init Container image names in the CR. By default, if you deploy a CR and do not explicitly specify container image values, the Operator automatically chooses the appropriate container images to use. Note If you install the Operator using the OpenShift command-line interface, the Operator installation archive includes a sample CR file called broker_activemqartemis_cr.yaml . In the sample CR, the spec.deploymentPlan.image property is included and set to its default value of placeholder . This value indicates that the Operator does not choose a broker container image until you deploy the CR. The spec.deploymentPlan.initImage property, which specifies the Init Container image, is not included in the broker_activemqartemis_cr.yaml sample CR file. If you do not explicitly include the spec.deploymentPlan.initImage property in your CR and specify a value, the Operator chooses an appropriate built-in Init Container image to use when you deploy the CR. How the Operator chooses these images is described in this section. To choose broker and Init Container images, the Operator first determines an AMQ Broker version to which the images should correspond. The Operator determines the version as follows: If the spec.upgrades.enabled property in the main CR is already set to true and the spec.version property specifies 7.7.0 , 7.8.0 , 7.8.1 , or 7.8.2 , the Operator uses that specified version. If spec.upgrades.enabled is not set to true , or spec.version is set to an AMQ Broker version earlier than 7.7.0 , the Operator uses the latest version of AMQ Broker (that is, 7.10.7 ). The Operator then detects your container platform. The AMQ Broker Operator can run on the following container platforms: OpenShift Container Platform (x86_64) OpenShift Container Platform on IBM Z (s390x) OpenShift Container Platform on IBM Power Systems (ppc64le) Based on the version of AMQ Broker and your container platform, the Operator then references two sets of environment variables in the operator.yaml configuration file. These sets of environment variables specify broker and Init Container images for various versions of AMQ Broker, as described in the following sub-sections. 2.4.1. Environment variables for broker container images The environment variables included in the operator.yaml configuration file for broker container images have the following naming convention: OpenShift Container Platform RELATED_IMAGE_ActiveMQ_Artemis_Broker_Kubernetes_ <AMQ_Broker_version_identifier> OpenShift Container Platform on IBM Z RELATED_IMAGE_ActiveMQ_Artemis_Broker_Kubernetes_ <AMQ_Broker_version_identifier> _s390x OpenShift Container Platform on IBM Power Systems RELATED_IMAGE_ActiveMQ_Artemis_Broker_Kubernetes_ <AMQ_Broker_version_identifier> _ppc64le Environment variable names for each supported container platform and specific AMQ Broker versions are shown in the table. Container platform Environment variable names OpenShift Container Platform RELATED_IMAGE_ActiveMQ_Artemis_Broker_Kubernetes_782 RELATED_IMAGE_ActiveMQ_Artemis_Broker_Kubernetes_790 RELATED_IMAGE_ActiveMQ_Artemis_Broker_Kubernetes_7100 OpenShift Container Platform on IBM Z RELATED_IMAGE_ActiveMQ_Artemis_Broker_Kubernetes_782_s390x RELATED_IMAGE_ActiveMQ_Artemis_Broker_Kubernetes_790_s390x RELATED_IMAGE_ActiveMQ_Artemis_Broker_Kubernetes_7100_s390x OpenShift Container Platform on IBM Power Systems RELATED_IMAGE_ActiveMQ_Artemis_Broker_Kubernetes_782_ppc64le RELATED_IMAGE_ActiveMQ_Artemis_Broker_Kubernetes_790_ppc64le RELATED_IMAGE_ActiveMQ_Artemis_Broker_Kubernetes_7100_ppc64le The value of each environment variable specifies a broker container image that is available from Red Hat. For example: - name: RELATED_IMAGE_ActiveMQ_Artemis_Broker_Kubernetes_7100 #value: registry.redhat.io/amq7/amq-broker-rhel8:7.10 value: registry.redhat.io/amq7/amq-broker-rhel8@sha256:982ba18be1ac285722bc0ca8e85d2a42b8b844ab840b01425e79e3eeee6ee5b9 Therefore, based on an AMQ Broker version and your container platform, the Operator determines the applicable environment variable name. The Operator uses the corresponding image value when starting the broker container. Note In the operator.yaml file, the Operator uses an image that is represented by a Secure Hash Algorithm (SHA) value. The comment line, which begins with a number sign ( # ) symbol, denotes that the SHA value corresponds to a specific container image tag. 2.4.2. Environment variables for Init Container images The environment variables included in the operator.yaml configuration file for Init Container images have the following naming convention: RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_ <AMQ_Broker_version_identifier> Environment variable names for specific AMQ Broker versions are listed below. RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_782 RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_790 RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_7100 The value of each environment variable specifies an Init Container image that is available from Red Hat. For example: - name: RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_7100 #value: registry.redhat.io/amq7/amq-broker-init-rhel8:0.4-21 value: registry.redhat.io/amq7/amq-broker-init-rhel8@sha256:f37f98c809c6f29a83e3d5a3ac4494e28efe9b25d33c54f533c6a08662244622 Therefore, based on an AMQ Broker version, the Operator determines the applicable environment variable name. The Operator uses the corresponding image value when starting the Init Container. Note As shown in the example, the Operator uses an image that is represented by a Secure Hash Algorithm (SHA) value. The comment line, which begins with a number sign ( # ) symbol, denotes that the SHA value corresponds to a specific container image tag. Observe that the corresponding container image tag is not a floating tag in the form of 0.4-21 . This means that the container image used by the Operator remains fixed. The Operator does not automatically pull and use a new micro image version (that is, 0.4-21-n , where n is the latest micro version) when it becomes available from Red Hat. The environment variables included in the operator.yaml configuration file for Init Container images have the following naming convention: OpenShift Container Platform RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_ <AMQ_Broker_version_identifier> OpenShift Container Platform on IBM Z RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_s390x_ <AMQ_Broker_version_identifier> OpenShift Container Platform on IBM Power Systems RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_ppc64le_ <AMQ_Broker_version_identifier> Environment variable names for each supported container platform and specific AMQ Broker versions are shown in the table. Container platform Environment variable names OpenShift Container Platform RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_782 RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_790 RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_7100 OpenShift Container Platform on IBM Z RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_s390x_782 RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_s390x_790 RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_s390x_7100 OpenShift Container Platform on IBM Power Systems RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_ppc64le_782 RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_ppc64le_790 RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_ppc64le_7100 The value of each environment variable specifies an Init Container image that is available from Red Hat. For example: - name: RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_7100 #value: registry.redhat.io/amq7/amq-broker-init-rhel8:0.4-21-1 value: registry.redhat.io/amq7/amq-broker-init-rhel8@sha256:f37f98c809c6f29a83e3d5a3ac4494e28efe9b25d33c54f533c6a08662244622 Therefore, based on an AMQ Broker version and your container platform, the Operator determines the applicable environment variable name. The Operator uses the corresponding image value when starting the Init Container. Note As shown in the example, the Operator uses an image that is represented by a Secure Hash Algorithm (SHA) value. The comment line, which begins with a number sign ( # ) symbol, denotes that the SHA value corresponds to a specific container image tag. Observe that the corresponding container image tag is not a floating tag in the form of 0.4-21 . This means that the container image used by the Operator remains fixed. The Operator does not automatically pull and use a new micro image version (that is, 0.4-21-n , where n is the latest micro version) when it becomes available from Red Hat. Additional resources To learn how to use the AMQ Broker Operator to create a broker deployment, see Chapter 3, Deploying AMQ Broker on OpenShift Container Platform using the AMQ Broker Operator . For more information about how the Operator uses an Init Container to generate the broker configuration, see Section 4.1, "How the Operator generates the broker configuration" . To learn how to build and specify a custom Init Container image, see Section 4.7, "Specifying a custom Init Container image" . 2.5. Operator deployment notes This section describes some important considerations when planning an Operator-based deployment Deploying the Custom Resource Definitions (CRDs) that accompany the AMQ Broker Operator requires cluster administrator privileges for your OpenShift cluster. When the Operator is deployed, non-administrator users can create broker instances via corresponding Custom Resources (CRs). To enable regular users to deploy CRs, the cluster administrator must first assign roles and permissions to the CRDs. For more information, see Creating cluster roles for Custom Resource Definitions in the OpenShift Container Platform documentation. When you update your cluster with the CRDs for the latest Operator version, this update affects all projects in the cluster. Any broker Pods deployed from versions of the Operator might become unable to update their status. When you click the Logs tab of a running broker Pod in the OpenShift Container Platform web console, you see messages indicating that 'UpdatePodStatus' has failed. However, the broker Pods and Operator in that project continue to work as expected. To fix this issue for an affected project, you must also upgrade that project to use the latest version of the Operator. While you can create more than one broker deployment in a given OpenShift project by deploying multiple Custom Resource (CR) instances, typically, you create a single broker deployment in a project, and then deploy multiple CR instances for addresses. Red Hat recommends you create broker deployments in separate projects. If you intend to deploy brokers with persistent storage and do not have container-native storage in your OpenShift cluster, you need to manually provision Persistent Volumes (PVs) and ensure that these are available to be claimed by the Operator. For example, if you want to create a cluster of two brokers with persistent storage (that is, by setting persistenceEnabled=true in your CR), you need to have two persistent volumes available. By default, each broker instance requires storage of 2 GiB. If you specify persistenceEnabled=false in your CR, the deployed brokers uses ephemeral storage. Ephemeral storage means that that every time you restart the broker Pods, any existing data is lost. For more information about provisioning persistent storage in OpenShift Container Platform, see: Understanding persistent storage You must add configuration for the items listed below to the main broker CR instance before deploying the CR for the first time. You cannot add configuration for these items to a broker deployment that is already running. The size and storage class of the Persistent Volume Claim (PVC) required by each broker in a deployment for persistent storage Limits and requests for memory and CPU for each broker in a deployment If you update a parameter in your CR that the Operator is unable to dynamically update in the StatefulSet, the Operator deletes the StatefulSet and recreates it with the updated parameter value. Deleting the StatefulSet causes all pods to be deleted and recreated, which causes a temporary broker outage. An example of a CR update that the Operator cannot dynamically update in the StatefulSet is if you change persistenceEnabled=false to persistenceEnabled=true . 2.6. Identifying namespaces watched by existing Operators If the cluster already contains installed Operators for AMQ Broker, and you want a new Operator to watch all or multiple namespaces, you must ensure that the new Operator does not watch any of the same namespaces as existing Operators. Use the following procedure to identify the namespaces watched by existing Operators. Procedure In the left pane of the OpenShift Container Platform web console, click Workloads Deployments . In the Project drop-down list, select All Projects . In the Filter Name box, specify a string, for example, amq , to display the Operators for AMQ Broker that are installed on the cluster. Note The namespace column displays the namespace where each operator is deployed . Check the namespaces that each installed Operator for AMQ Broker is configured to watch . Click the Operator name to display the Operator details and click the YAML tab. Search for WATCH_NAMESPACE and note the namespaces that the Operator watches. If the WATCH_NAMESPACE section has a fieldPath field that has a value of metadata.namespace , the Operator is watching the namespace where it is deployed. If the WATCH_NAMESPACE section has a value field that has list of namespaces, the Operator is watching the specified namespaces. For example: - name: WATCH_NAMESPACE value: "namespace1, namespace2" If the WATCH_NAMESPACE section has a value field that is empty or has an asterisk, the Operator is watching all the namespaces on the cluster. For example: - name: WATCH_NAMESPACE value: "" In this case, before you deploy the new Operator, you must either uninstall the existing Operator or reconfigure it to watch specific namespaces. The procedures in the section show you how to install the Operator and use Custom Resources (CRs) to create broker deployments on OpenShift Container Platform. When you have successfully completed the procedures, you will have the Operator running in an individual Pod. Each broker instance that you create will run as an individual Pod in a StatefulSet in the same project as the Operator. Later, you will you will see how to use a dedicated addressing CR to define addresses in your broker deployment.

Commands:
- name: RELATED_IMAGE_ActiveMQ_Artemis_Broker_Kubernetes_7100 #value: registry.redhat.io/amq7/amq-broker-rhel8:7.10 value: registry.redhat.io/amq7/amq-broker-rhel8@sha256:982ba18be1ac285722bc0ca8e85d2a42b8b844ab840b01425e79e3eeee6ee5b9
- name: RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_7100 #value: registry.redhat.io/amq7/amq-broker-init-rhel8:0.4-21 value: registry.redhat.io/amq7/amq-broker-init-rhel8@sha256:f37f98c809c6f29a83e3d5a3ac4494e28efe9b25d33c54f533c6a08662244622
- name: RELATED_IMAGE_ActiveMQ_Artemis_Broker_Init_7100 #value: registry.redhat.io/amq7/amq-broker-init-rhel8:0.4-21-1 value: registry.redhat.io/amq7/amq-broker-init-rhel8@sha256:f37f98c809c6f29a83e3d5a3ac4494e28efe9b25d33c54f533c6a08662244622
- name: WATCH_NAMESPACE value: "namespace1, namespace2"
- name: WATCH_NAMESPACE value: ""