redis cache - better parsing of connection uri (#2579)

* better parsing of connection uri

* added changelog fragment

* fixed tests for ansible 2.9

* Update tests/unit/plugins/cache/test_redis.py

Co-authored-by: Felix Fontein <felix@fontein.de>

* Update tests/unit/plugins/cache/test_redis.py

Co-authored-by: Felix Fontein <felix@fontein.de>

* Adjustments from PR

* Update test_redis.py

* Update test_redis.py

* Update plugins/cache/redis.py

Co-authored-by: Felix Fontein <felix@fontein.de>

* Update plugins/cache/redis.py

Co-authored-by: Felix Fontein <felix@fontein.de>

* Update tests/unit/plugins/cache/test_redis.py

Co-authored-by: Felix Fontein <felix@fontein.de>

Co-authored-by: Felix Fontein <felix@fontein.de>

changelogs/fragments/2579-redis-cache-ipv6.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - redis cache - improved connection string parsing (https://github.com/ansible-collections/community.general/issues/497).

plugins/cache/redis.py

@@ -61,6 +61,7 @@ DOCUMENTATION = '''
         type: integer
 '''
 
+import re
 import time
 import json
 
@@ -91,6 +92,8 @@ class CacheModule(BaseCacheModule):
     performance.
     """
     _sentinel_service_name = None
+    re_url_conn = re.compile(r'^([^:]+|\[[^]]+\]):(\d+):(\d+)(?::(.*))?$')
+    re_sent_conn = re.compile(r'^(.*):(\d+)$')
 
     def __init__(self, *args, **kwargs):
         uri = ''
@@ -130,11 +133,18 @@ class CacheModule(BaseCacheModule):
             self._db = self._get_sentinel_connection(uri, kw)
         # normal connection
         else:
-            connection = uri.split(':')
+            connection = self._parse_connection(self.re_url_conn, uri)
             self._db = StrictRedis(*connection, **kw)
 
         display.vv('Redis connection: %s' % self._db)
 
+    @staticmethod
+    def _parse_connection(re_patt, uri):
+        match = re_patt.match(uri)
+        if not match:
+            raise AnsibleError("Unable to parse connection string")
+        return match.groups()
+
     def _get_sentinel_connection(self, uri, kw):
         """
         get sentinel connection details from _uri
@@ -158,7 +168,7 @@ class CacheModule(BaseCacheModule):
             except IndexError:
                 pass  # password is optional
 
-        sentinels = [tuple(shost.split(':')) for shost in connections]
+        sentinels = [self._parse_connection(self.re_sent_conn, shost) for shost in connections]
         display.vv('\nUsing redis sentinels: %s' % sentinels)
         scon = Sentinel(sentinels, **kw)
         try:

tests/unit/plugins/cache/test_redis.py

@@ -23,10 +23,23 @@ import pytest
 
 pytest.importorskip('redis')
 
+from ansible import constants as C
 from ansible.plugins.loader import cache_loader
+from ansible.release import __version__ as ansible_version
 from ansible_collections.community.general.plugins.cache.redis import CacheModule as RedisCache
 
 
 def test_redis_cachemodule():
     # The _uri option is required for the redis plugin
-    assert isinstance(cache_loader.get('community.general.redis', **{'_uri': '127.0.0.1:6379:1'}), RedisCache)
+    connection = '127.0.0.1:6379:1'
+    if ansible_version.startswith('2.9.'):
+        C.CACHE_PLUGIN_CONNECTION = connection
+    assert isinstance(cache_loader.get('community.general.redis', **{'_uri': connection}), RedisCache)
+
+
+def test_redis_cachemodule():
+    # The _uri option is required for the redis plugin
+    connection = '[::1]:6379:1'
+    if ansible_version.startswith('2.9.'):
+        C.CACHE_PLUGIN_CONNECTION = connection
+    assert isinstance(cache_loader.get('community.general.redis', **{'_uri': connection}), RedisCache)