use redis_exporter provided by ROCK instead of 3rd party image, add r…

…edis_exporter as service in pebble layer, run redis in appendonly mode

metadata.yaml

@@ -47,18 +47,12 @@ containers:
         location: /var/lib/redis
   sentinel:
     resource: redis-image
-  exporter:
-    resource: exporter
 
 resources:
   redis-image:
     type: oci-image
     description: ubuntu lts docker image for redis
-    upstream: ghcr.io/canonical/charmed-redis:7.0-22.04_edge
-  exporter:
-    type: oci-image
-    description: redis exporter for prometheus metrics
-    upstream: docker.io/oliver006/redis_exporter:v1.59.0
+    upstream: ghcr.io/canonical/charmed-redis:7.2.5-22.04-edge
   cert-file:
     type: file
     filename: redis.crt

src/charm.py

@@ -38,8 +38,8 @@
     SENTINEL_PASSWORD_KEY,
     SOCKET_TIMEOUT,
     WAITING_MESSAGE,
+    WORKING_DIR,
 )
-from redis_exporter import Exporter
 from sentinel import Sentinel
 
 logger = logging.getLogger(__name__)
@@ -60,7 +60,6 @@ def __init__(self, *args):
         self._namespace = self.model.name
         self.redis_provides = RedisProvides(self, port=REDIS_PORT)
         self.sentinel = Sentinel(self)
-        self.exporter = Exporter(self)
         self.metrics_endpoint = MetricsEndpointProvider(
             self,
             jobs=[
@@ -209,7 +208,6 @@ def _config_changed(self, event: EventBase) -> None:
 
         self._update_layer()
         self.sentinel._update_sentinel_layer()
-        self.exporter._update_exporter_layer()
 
         # update_layer will set a Waiting status if Pebble is not ready
         if not isinstance(self.unit.status, ActiveStatus):
@@ -351,8 +349,8 @@ def _update_layer(self) -> None:
         if current_layer.services != new_layer.services:
             container.add_layer("redis", new_layer, combine=True)
             logger.info("Added updated layer 'redis' to Pebble plan")
-            container.restart("redis")
-            logger.info("Restarted redis service")
+            container.restart("redis", "redis_exporter")
+            logger.info("Restarted redis and redis_exporter services")
 
         self.unit.status = ActiveStatus()
 
@@ -370,9 +368,20 @@ def _redis_layer(self) -> Layer:
                     "override": "replace",
                     "summary": "Redis service",
                     "command": f"redis-server {self._redis_extra_flags()}",
-                    "user": "redis",
-                    "group": "redis",
+                    "user": REDIS_USER,
+                    "group": REDIS_USER,
                     "startup": "enabled",
+                },
+                "redis_exporter": {
+                    "override": "replace",
+                    "summary": "Redis metric exporter",
+                    "command": "bin/redis_exporter",
+                    "user": REDIS_USER,
+                    "group": REDIS_USER,
+                    "startup": "enabled",
+                    "environment": {
+                        "REDIS_PASSWORD": self._get_password(),
+                    },
                 }
             },
         }
@@ -390,6 +399,8 @@ def _redis_extra_flags(self) -> str:
             f"--masterauth {self._get_password()}",
             f"--replica-announce-ip {self.unit_pod_hostname}",
             f"--logfile {LOG_FILE}",
+            "--appendonly yes",
+            f"--dir {WORKING_DIR}",
         ]
 
         if self._peers.data[self.app].get("enable-password", "true") == "false":

src/literals.py

@@ -20,4 +20,5 @@
 LOG_DIR = "/var/log/redis"
 LOG_FILE = f"{LOG_DIR}/redis-server.log"
 CONFIG_DIR = "/etc/redis-server"
+WORKING_DIR = "/var/lib/redis/"
 SENTINEL_CONFIG_PATH = f"{CONFIG_DIR}/sentinel.conf"