Add autovars feature to Gardener plugin

Signed-off-by: Matthias Büchse <matthias.buechse@alasca.cloud>

Author: mbuechse

Tests/kaas/plugin/gardener_helper.py

@@ -23,6 +23,13 @@ def setup_client_config(client_config: Configuration, kubeconfig, cwd='.'):
         ))
 
 
+def get_cloudprofile(api_instance: CustomObjectsApi, namespace, name):
+    """mimic `kubectl get cloudprofile`"""
+    return api_instance.get_cluster_custom_object(
+        GARDENER_GROUP, GARDENER_VERSION, 'cloudprofiles', name,
+    )
+
+
 def create_shoot(co_api: CustomObjectsApi, namespace: str, body: dict):
     return co_api.create_namespaced_custom_object(
         group=GARDENER_GROUP,

Tests/kaas/plugin/plugin_gardener.py

@@ -146,6 +146,38 @@ def __init__(self, plugin_config, basepath='.', cwd='.', name=None):
     def _render_template(self, key):
         return self.template_map[key].render(**self.vars, **self.secrets)
 
+    def _auto_vars_noris(self, api_instance: _gh.CustomObjectsApi):
+        logging.debug('using autoVars/noris')
+        cloud_profile = _gh.get_cloudprofile(api_instance, self.namespace, self.vars['cloud_profile_name'])
+        version_items = cloud_profile['spec']['kubernetes']['versions']
+        # filter by kubernetesVersion and classification==supported
+        version_prefix = f"{self.config['kubernetesVersion']}."
+        versions = [
+            item['version']
+            for item in version_items
+            if item['classification'] == 'supported'
+            if item['version'].startswith(version_prefix)
+        ]
+        logging.debug(f'matching k8s versions: {versions}')
+        if not versions:
+            raise RuntimeError(f'autoVars/noris failed: no versions found for v{version_prefix}x')
+        # select latest patch version (assume patch part is numeric)
+        selected_version = max(versions, key=lambda ver: int(ver.rsplit('.', 1)[-1]))
+        return {'kubernetes_version': selected_version}
+
+    def _auto_vars(self, auto_vars_kind, co_api: _gh.CustomObjectsApi):
+        # set default values regardless of auto_vars_kind
+        self.vars.setdefault('num_worker_nodes', 3)
+        # now on to specifics
+        if not auto_vars_kind:
+            return
+        if auto_vars_kind == 'noris':
+            auto_vars = self._auto_vars_noris(co_api)
+        else:
+            raise RuntimeError(f'unknown kind of autoVars: {auto_vars_kind}')
+        logger.debug(f'applying autoVars/{auto_vars_kind}: {auto_vars}')
+        self.vars.update(auto_vars)
+
     def _write_shoot_yaml(self, shoot_yaml):
         # write out shoot.yaml for purposes of documentation
         # we will however use the dict instead of calling the shell with `kubectl apply -f`
@@ -164,6 +196,7 @@ def _write_kubeconfig(self, kubeconfig):
     def create_cluster(self):
         with ApiClient(self.client_config) as api_client:
             co_api = _gh.CustomObjectsApi(api_client)
+            self._auto_vars(self.config.get('autoVars'), co_api)
             shoot_yaml = self._render_template('shoot')
             shoot_dict = yaml.load(shoot_yaml, Loader=yaml.SafeLoader)
             self._write_shoot_yaml(shoot_yaml)

playbooks/clusters.yaml.j2

@@ -4,6 +4,8 @@ clusters:
     kind: gardener
     config:
       name: 'noris-1-33'  # explicit name because dot in name not permissible
+      kubernetesVersion: '1.33'
+      autoVars: noris  # determine vars.kubernetes_version automatically using kubernetesVersion
       templates:
         shoot: shoot.yaml
         kubeconfig: garden-kubeconfig.yaml
@@ -29,6 +31,8 @@ clusters:
     kind: gardener
     config:
       name: 'noris-1-34'  # explicit name because dot in name not permissible
+      kubernetesVersion: '1.34'
+      autoVars: noris  # determine vars.kubernetes_version automatically using kubernetesVersion
       templates:
         shoot: shoot.yaml
         kubeconfig: garden-kubeconfig.yaml