Ansible Based Operator Scaffolding
A new Ansible operator project can be created using a command that looks like the following:
operator-sdk init --plugins ansible \ --domain=my.domain \ --group=apps --version=v1alpha1 --kind=AppService \ --generate-playbook \ --generate-role
The new project directory has many generated folders and files. The following table describes a basic rundown of each generated file/directory.
|Dockerfile||The Dockerfile for building the container image for the operator.|
|Makefile||Contains make targets for building, publishing, deploying the container image that wraps the operator binary, and make targets for installing and uninstalling the CRD.|
|PROJECT||A YAML file containing meta information for the operator.|
|config/crd||The base CRD files and the kustomization settings.|
|config/default||Collects all operator manifests for deployment, used by
|config/manager||The controller manager deployment.|
|config/prometheus||The ServiceMonitor resource for monitoring the operator.|
|config/rbac||The role, role binding for leader election and authentication proxy.|
|config/samples||The sample resources created for the CRDs.|
|config/testing||Some sample configurations for testing.|
|playbooks/||A subdirectory for the playbooks to run.|
|roles/||A subdirectory for the roles tree to run.|
|watches.yaml||The Group, Version, and Kind of the resources to watch, and the Ansible invocation method. New entries are added via the ‘create api’ command.|
|requirements.yml||A YAML file containing the Ansible collections and role dependencies to install during build.|
|molecule/||The Molecule scenarios for end-to-end testing of your role and operator|
The default Deployment manifest generated for the operator can be found in the
config/manager/manager.yaml file. By default, the Deployment is named as
‘controller-manager’. It contains a single container named ‘manager’, and it
may pick up a sidecar patch from the
config/default directory. The
Deployment will create a single Pod.
For the container in the Pod, there are a few things to note. The default
Deployment contains a placeholder for the container image to use, so you
cannot create a meaningful operator using the YAML file directly. To deploy
the operator, you will run
make deploy IMG=<IMG>. The image name and tag
are then patched using kustomize.
The Volume Mount Path
The default EmptyDir volume mounted at
/tmp/ansible-operator/runner is used
to serve the input directory in ansible-runner’s terms.
The mount path can NOT be changed to other paths, or else the Operator will
fail to communicate with ansible-runner.
The Environment Variables
You can customize the behavior of the Ansible operator by specifying the environment variables for the container. Please refer to the Ansible Documentation for a list of environment variables that can be used to tune the behavior of the Ansible engine.
In addition to the Ansible environment variables, Operator SDK also support some special environment variables:
WATCH_NAMESPACE: This is the namespace your operator will watch for resource changes, i.e. resource create, update or delete operations. In the scaffolded operator Deployment, this is set to the same namespace in which the operator is deployed. This variable can be set to one of the following types of values:
‘': An empty string means that the operator will watch all namespaces. This is the default value if the
WATCH_NAMESPACEenvironment variable is not set. It is especially useful for watching cluster-scoped resources.
foo: The operator will watch the namespace named
foo. This is the setting you will use if you are operating a namespaced resource which is deployed into a specific namespace.
foo,bar: The operator checks the value of the environment variable and realizes that it is a comma-separated list. This means the operator will watch for resources in each of the listed namespaces.
ANSIBLE_DEBUG_LOGS: A boolean value for toggling the Ansible output during reconciliation. When set to True, the operator dumps the Ansible result into its standard output.
ANSIBLE_ROLES_PATH: The parent path(s) for the Ansible roles. When there are more than one path to set, you can use “:” to separate them. Given a path
/opt/fooand a role name
bar, the Ansible operator will check if the Ansible role can be found in either
This value overrides the setting from the
ANSIBLE_COLLECTIONS_PATH: The base path for the Ansible collections which defaults to
ANSIBLE_COLLECTIONS_PATHis not explicitly specified. When a fully qualified collection name in the watches file, the Ansible operator checks if the specified collection can found under the base path that can be customized using this variable. Suppose you have
/fooand the fully qualified collection name set to
example.com.bar, the Ansible operator searches for the roles under
This value takes precedence over the
MAX_CONCURRENT_RECONCILES_<kind>_<group>: This specifies the maximum number of concurrent reconciliations for the operator. It defaults to the number of CPUs. You can adjust this based on the cluster resources.
WORKER_<kind>_<group>: Deprecated. Use
ANSIBLE_VERBOSITY_<kind>_<group>: This is used to customize the verbosity of the ansible-runner command. The default value is 2. The value must be no less than 0 and no greater than 7. This value takes precedence over the global
--ansible-verbosityflag, and it can be overridden by the per-resource annotation named