helm: add support for history-max parameter (#164)

* helm: add support for history-max parameter

The --history-max parameter allows the user to set a maximum amount of
revisions per release to be kept in the history.

By default helm keeps 10 revisions per release, which means that 10
secrets will be kept per release.

* helm: remove default for history_max

When the history_max option is not set, the module will not pass
'--history-max' to the CLI command. This ensures that the defaults of
the helm CLI will alwasy be used.

* helm: remove whitespace trail

* helm: add mutually exclusive logic

The 'history_max' parameter is not available when using the 'helm
install' command, it is only implemented for 'helm ugprade'.

The 'replace' option uses the 'install' parameter, thus 'replace' and
'history_max' have to be mutually exclusive.

* helm: formatting changes

changelogs/fragments/164-add-history-max.yaml

@@ -0,0 +1,2 @@
+minor_changes:
+  - helm - add support for history_max cli parameter (https://github.com/ansible-collections/kubernetes.core/pull/164).

plugins/modules/helm.py

@@ -130,6 +130,7 @@
     description:
       - Reuse the given name, only if that name is a deleted release which remains in the history.
       - This is unsafe in production environment.
+      - mutually exclusive with with C(history_max).
     type: bool
     default: False
     version_added: "1.11.0"
@@ -139,6 +140,12 @@
     type: bool
     default: False
     version_added: "1.2.0"
+  history_max:
+    description:
+      - Limit the maximum number of revisions saved per release.
+      - mutually exclusive with with C(replace).
+    type: int
+    version_added: "2.2.0"
 extends_documentation_fragment:
   - kubernetes.core.helm_common_options
 '''
@@ -357,7 +364,7 @@ def fetch_chart_info(module, command, chart_ref):
 
 
 def deploy(command, release_name, release_values, chart_name, wait,
-           wait_timeout, disable_hook, force, values_files, atomic=False,
+           wait_timeout, disable_hook, force, values_files, history_max, atomic=False,
            create_namespace=False, replace=False, skip_crds=False):
     """
     Install/upgrade/rollback release chart
@@ -404,8 +411,10 @@ def deploy(command, release_name, release_values, chart_name, wait,
     if skip_crds:
         deploy_command += " --skip-crds"
 
-    deploy_command += " " + release_name + " " + chart_name
+    if history_max is not None:
+        deploy_command += " --history-max=%s" % str(history_max)
 
+    deploy_command += " " + release_name + " " + chart_name
     return deploy_command
 
 
@@ -532,6 +541,7 @@ def main():
             create_namespace=dict(type='bool', default=False),
             replace=dict(type='bool', default=False),
             skip_crds=dict(type='bool', default=False),
+            history_max=dict(type='int'),
 
             # Generic auth key
             host=dict(type='str', fallback=(env_fallback, ['K8S_AUTH_HOST'])),
@@ -546,6 +556,7 @@ def main():
         mutually_exclusive=[
             ("context", "ca_cert"),
             ("kubeconfig", "ca_cert"),
+            ("replace", "history_max"),
         ],
         supports_check_mode=True,
     )
@@ -575,6 +586,7 @@ def main():
     create_namespace = module.params.get('create_namespace')
     replace = module.params.get('replace')
     skip_crds = module.params.get('skip_crds')
+    history_max = module.params.get('history_max')
 
     if bin_path is not None:
         helm_cmd_common = bin_path
@@ -610,7 +622,7 @@ def main():
             helm_cmd = deploy(helm_cmd, release_name, release_values, chart_ref, wait, wait_timeout,
                               disable_hook, False, values_files=values_files, atomic=atomic,
                               create_namespace=create_namespace, replace=replace,
-                              skip_crds=skip_crds)
+                              skip_crds=skip_crds, history_max=history_max)
             changed = True
 
         else:
@@ -627,7 +639,7 @@ def main():
                 helm_cmd = deploy(helm_cmd, release_name, release_values, chart_ref, wait, wait_timeout,
                                   disable_hook, force, values_files=values_files, atomic=atomic,
                                   create_namespace=create_namespace, replace=replace,
-                                  skip_crds=skip_crds)
+                                  skip_crds=skip_crds, history_max=history_max)
                 changed = True
 
     if module.check_mode: