Fix the linode inventory plugin, and the redis and memcached cache plugins (#1281, #1282, #1283).

changelogs/fragments/fix-plugin-imports.yml

@@ -0,0 +1,4 @@
+bugfixes:
+- "linode inventory plugin - make sure that plugin errors out on initialization if the required library is not found, and not on load-time (https://github.com/ansible-collections/community.general/pull/1297)."
+- "redis cache plugin - make sure that plugin errors out on initialization if the required library is not found, and not on load-time (https://github.com/ansible-collections/community.general/pull/1297)."
+- "memcached cache plugin - make sure that plugin errors out on initialization if the required library is not found, and not on load-time (https://github.com/ansible-collections/community.general/pull/1297)."

plugins/cache/memcached.py

@@ -57,8 +57,9 @@ from ansible.utils.display import Display
 
 try:
     import memcache
+    HAS_MEMCACHE = True
 except ImportError:
-    raise AnsibleError("python-memcached is required for the memcached fact cache")
+    HAS_MEMCACHE = False
 
 display = Display()
 
@@ -187,6 +188,9 @@ class CacheModule(BaseCacheModule):
             self._timeout = C.CACHE_PLUGIN_TIMEOUT
             self._prefix = C.CACHE_PLUGIN_PREFIX
 
+        if not HAS_MEMCACHE:
+            raise AnsibleError("python-memcached is required for the memcached fact cache")
+
         self._cache = {}
         self._db = ProxyClientPool(connection, debug=0)
         self._keys = CacheModuleKeys(self._db, self._db.get(CacheModuleKeys.PREFIX) or [])

plugins/cache/redis.py

@@ -73,8 +73,9 @@ from ansible.utils.display import Display
 
 try:
     from redis import StrictRedis, VERSION
+    HAS_REDIS = True
 except ImportError:
-    raise AnsibleError("The 'redis' python module (version 2.4.5 or newer) is required for the redis fact cache, 'pip install redis'")
+    HAS_REDIS = False
 
 display = Display()
 
@@ -111,6 +112,9 @@ class CacheModule(BaseCacheModule):
             self._prefix = C.CACHE_PLUGIN_PREFIX
             self._keys_set = 'ansible_cache_keys'
 
+        if not HAS_REDIS:
+            raise AnsibleError("The 'redis' python module (version 2.4.5 or newer) is required for the redis fact cache, 'pip install redis'")
+
         self._cache = {}
         kw = {}
 

plugins/inventory/linode.py

@@ -63,8 +63,9 @@ from ansible.plugins.inventory import BaseInventoryPlugin
 try:
     from linode_api4 import LinodeClient
     from linode_api4.errors import ApiError as LinodeApiError
+    HAS_LINODE = True
 except ImportError:
-    raise AnsibleError('the Linode dynamic inventory plugin requires linode_api4.')
+    HAS_LINODE = False
 
 
 class InventoryModule(BaseInventoryPlugin):
@@ -194,6 +195,9 @@ class InventoryModule(BaseInventoryPlugin):
         """Dynamically parse Linode the cloud inventory."""
         super(InventoryModule, self).parse(inventory, loader, path)
 
+        if not HAS_LINODE:
+            raise AnsibleError('the Linode dynamic inventory plugin requires linode_api4.')
+
         config_data = self._read_config_data(path)
         self._build_client()