5.4. Ansible-based Operators

Procedure

1. Create a project.

   1. Create your project directory:

      $ mkdir memcached-operator

   2. Change into the project directory:

      $ cd memcached-operator

   3. Run the operator-sdk init command with the ansible plugin to initialize the project:

      $ operator-sdk init \
          --plugins=ansible \
          --domain=example.com

2. Create an API.

   Create a simple Memcached API:

   $ operator-sdk create api \
       --group cache \
       --version v1 \
       --kind Memcached \
       --generate-role 

   1

   1

   Generates an Ansible role for the API.

3. Build and push the Operator image.

   Use the default Makefile targets to build and push your Operator. Set IMG with a pull spec for your image that uses a registry you can push to:

   $ make docker-build docker-push IMG=<registry>/<user>/<image_name>:<tag>

4. Run the Operator.

   1. Install the CRD:

      $ make install

   2. Deploy the project to the cluster. Set IMG to the image that you pushed:

      $ make deploy IMG=<registry>/<user>/<image_name>:<tag>

5. Create a sample custom resource (CR).

   1. Create a sample CR:

      $ oc apply -f config/samples/cache_v1_memcached.yaml \
          -n memcached-operator-system

   2. Watch for the CR to reconcile the Operator:

      $ oc logs deployment.apps/memcached-operator-controller-manager \
          -c manager \
          -n memcached-operator-system

      Example output

      ...
      I0205 17:48:45.881666       7 leaderelection.go:253] successfully acquired lease memcached-operator-system/memcached-operator
      {"level":"info","ts":1612547325.8819902,"logger":"controller-runtime.manager.controller.memcached-controller","msg":"Starting EventSource","source":"kind source: cache.example.com/v1, Kind=Memcached"}
      {"level":"info","ts":1612547325.98242,"logger":"controller-runtime.manager.controller.memcached-controller","msg":"Starting Controller"}
      {"level":"info","ts":1612547325.9824686,"logger":"controller-runtime.manager.controller.memcached-controller","msg":"Starting workers","worker count":4}
      {"level":"info","ts":1612547348.8311093,"logger":"runner","msg":"Ansible-runner exited successfully","job":"4037200794235010051","name":"memcached-sample","namespace":"memcached-operator-system"}

6. Delete a CR.

   Delete a CR by running the following command:

   $ oc delete -f config/samples/cache_v1_memcached.yaml -n memcached-operator-system

7. Clean up.

   Run the following command to clean up the resources that have been created as part of this procedure:

   $ make undeploy