Ansible Operator Watches
The Watches file contains a list of mappings from custom resources, identified
by it’s Group, Version, and Kind, to an Ansible Role or Playbook. The Operator
expects this mapping file in a predefined location: /opt/ansible/watches.yaml
These resources, as well as child resources (determined by owner references) will
be monitored for updates and cached.
- group: The group of the Custom Resource that you will be watching.
- version: The version of the Custom Resource that you will be watching.
- kind: The kind of the Custom Resource that you will be watching.
- role (default): Specifies a role to be executed. This field is mutually exclusive with the
“playbook” field. This field can be:
- an absolute path to a role directory.
- a relative path within one of the directories specified by
ANSIBLE_ROLES_PATH
environment variable oransible-roles-path
flag. - a relative path within the current working directory, which defaults to
/opt/ansible/roles
. - a fully qualified collection name of an installed Ansible collection. Ansible collections are installed to
~/.ansible/collections
or/usr/share/ansible/collections
by default. If they are installed elsewhere, use theANSIBLE_COLLECTIONS_PATH
environment variable or theansible-collections-path
flag
- playbook: This is the playbook name that you have added to the container. This playbook is expected to be simply a way to call roles. This field is mutually exclusive with the “role” field. When running locally, the playbook is expected to be in the current project directory.
- vars: This is an arbitrary map of key-value pairs. The contents will be
passed as
extra_vars
to the playbook or role specified for this watch. - reconcilePeriod (optional): The maximum interval in seconds that the operator will wait before beginning another reconcile, even if no watched events are received. When an operator watches many resources, each reconcile can become expensive, and a low value here can actually reduce performance. Typically, this option should only be used in advanced use cases where
watchDependentResources
is set toFalse
and when is not possible to use the watch feature. E.g To managing external resources that don’t raise Kubernetes events. - manageStatus (optional): When true (default), the operator will manage the status of the CR generically. Set to false, the status of the CR is managed elsewhere, by the specified role/playbook or in a separate controller.
- blacklist: A list of child resources (by GVK) that will not be watched or cached.
An example Watches file:
---
# Simple example mapping Foo to the Foo role
- version: v1alpha1
group: foo.example.com
kind: Foo
role: Foo
# Simple example mapping Bar to a playbook
- version: v1alpha1
group: bar.example.com
kind: Bar
playbook: playbook.yml
# More complex example for our Baz kind
# Here we will disable requeuing and be managing the CR status in the playbook,
# and specify additional variables.
- version: v1alpha1
group: baz.example.com
kind: Baz
playbook: baz.yml
reconcilePeriod: 0
manageStatus: False
vars:
foo: bar
# ConfigMaps owned by a Memcached CR will not be watched or cached.
- version: v1alpha1
group: cache.example.com
kind: Memcached
role: /opt/ansible/roles/memcached
blacklist:
- group: ""
version: v1
kind: ConfigMap
# Example usage with a role from an installed Ansible collection
- version: v1alpha1
group: bar.example.com
kind: Bar
role: myNamespace.myCollection.myRole
# Example filtering of resources with specific labels
- version: v1alpha1
group: bar.example.com
kind: Bar
playbook: playbook.yml
selector:
matchLabels:
foo: bar
matchExpressions:
- {key: foo, operator: In, values: [bar]}
- {key: baz, operator: Exists, values: []}
The advanced features can be enabled by adding them to your watches file per GVK.
They can go below the group
, version
, kind
and playbook
or role
.
Some features can be overridden per resource via an annotation on that CR. The options that are overridable will have the annotation specified below.
Feature | Yaml Key | Description | Annotation for override | default | Documentation |
---|---|---|---|---|---|
Reconcile Period | reconcilePeriod |
time between reconcile runs for a particular CR | ansible.sdk.operatorframework.io/reconcile-period | 1m | |
Manage Status | manageStatus |
Allows the ansible operator to manage the conditions section of each resource’s status section. | true | ||
Watching Dependent Resources | watchDependentResources |
Allows the ansible operator to dynamically watch resources that are created by ansible | true | dependent watches | |
Watching Cluster-Scoped Resources | watchClusterScopedResources |
Allows the ansible operator to watch cluster-scoped resources that are created by ansible | false | ||
Max Runner Artifacts | maxRunnerArtifacts |
Manages the number of artifact directories that ansible runner will keep in the operator container for each individual resource. | ansible.sdk.operatorframework.io/max-runner-artifacts | 20 | |
Finalizer | finalizer |
Sets a finalizer on the CR and maps a deletion event to a playbook or role | finalizers | ||
Selector | selector |
Identifies a set of objects based on their labels | None Applied | Labels and Selectors | |
Automatic Case Conversion | snakeCaseParameters |
Determines whether to convert the CR spec from camelCase to snake_case before passing the contents to Ansible as extra_vars | true |
Example
---
- version: v1alpha1
group: app.example.com
kind: AppService
playbook: playbook.yml
maxRunnerArtifacts: 30
reconcilePeriod: 5s
manageStatus: False
watchDependentResources: False
snakeCaseParameters: False
finalizer:
name: finalizer.app.example.com
vars:
state: absent
Note: By using the command operator-sdk add api
you are able to add additional CRDs to the project API, which can aid in designing your solution using concepts such as encapsulation, single responsibility principle, and cohesion, which could make the project easier to read, debug, and maintain. With this approach, you are able to customize and optimize the configurations more specifically per GVK via the watches.yaml
file.
Example:
---
- version: v1alpha1
group: app.example.com
kind: AppService
playbook: playbook.yml
maxRunnerArtifacts: 30
reconcilePeriod: 5s
manageStatus: False
watchDependentResources: False
finalizer:
name: finalizer.app.example.com
vars:
state: absent
- version: v1alpha1
group: app.example.com
kind: Database
playbook: playbook.yml
watchDependentResources: True
manageStatus: True