[DPE-2055] PGB extensions suport (#93)

* Update snap charm lib

* Update lock

* Initial plugin support

* Integration test

charmcraft.yaml

@@ -20,3 +20,4 @@ parts:
   charm:
     charm-binary-python-packages:
       - psycopg2-binary==2.9.6  # renovate
+      - psycopg[binary]==3.1.9  # renovate

lib/charms/operator_libs_linux/v1/snap.py → lib/charms/operator_libs_linux/v2/snap.py

@@ -79,11 +79,11 @@
 LIBID = "05394e5893f94f2d90feb7cbe6b633cd"
 
 # Increment this major API version when introducing breaking changes
-LIBAPI = 1
+LIBAPI = 2
 
 # Increment this PATCH version before using `charmcraft publish-lib` or reset
 # to 0 if you are raising the major API version
-LIBPATCH = 12
+LIBPATCH = 0
 
 
 # Regex to locate 7-bit C1 ANSI sequences
@@ -222,7 +222,7 @@ def __init__(
         name,
         state: SnapState,
         channel: str,
-        revision: int,
+        revision: str,
         confinement: str,
         apps: Optional[List[Dict[str, str]]] = None,
         cohort: Optional[str] = "",
@@ -415,7 +415,7 @@ def restart(
         """Restarts a snap's services.
 
         Args:
-            services (list): (optional) list of individual snap services to show logs from.
+            services (list): (optional) list of individual snap services to restart.
                 (otherwise all)
             reload (bool): (optional) flag to use the service reload command, if available.
                 Default `False`
@@ -427,7 +427,7 @@ def _install(
         self,
         channel: Optional[str] = "",
         cohort: Optional[str] = "",
-        revision: Optional[int] = None,
+        revision: Optional[str] = None,
     ) -> None:
         """Add a snap to the system.
 
@@ -454,7 +454,7 @@ def _refresh(
         self,
         channel: Optional[str] = "",
         cohort: Optional[str] = "",
-        revision: Optional[int] = None,
+        revision: Optional[str] = None,
         leave_cohort: Optional[bool] = False,
     ) -> None:
         """Refresh a snap.
@@ -498,7 +498,7 @@ def ensure(
         classic: Optional[bool] = False,
         channel: Optional[str] = "",
         cohort: Optional[str] = "",
-        revision: Optional[int] = None,
+        revision: Optional[str] = None,
     ):
         """Ensure that a snap is in a given state.
 
@@ -575,7 +575,7 @@ def state(self, state: SnapState) -> None:
         self._state = state
 
     @property
-    def revision(self) -> int:
+    def revision(self) -> str:
         """Returns the revision for a snap."""
         return self._revision
 
@@ -828,7 +828,7 @@ def _load_installed_snaps(self) -> None:
                 name=i["name"],
                 state=SnapState.Latest,
                 channel=i["channel"],
-                revision=int(i["revision"]),
+                revision=i["revision"],
                 confinement=i["confinement"],
                 apps=i.get("apps", None),
             )
@@ -846,7 +846,7 @@ def _load_info(self, name) -> Snap:
             name=info["name"],
             state=SnapState.Available,
             channel=info["channel"],
-            revision=int(info["revision"]),
+            revision=info["revision"],
             confinement=info["confinement"],
             apps=None,
         )
@@ -859,7 +859,7 @@ def add(
     channel: Optional[str] = "",
     classic: Optional[bool] = False,
     cohort: Optional[str] = "",
-    revision: Optional[int] = None,
+    revision: Optional[str] = None,
 ) -> Union[Snap, List[Snap]]:
     """Add a snap to the system.
 
@@ -871,7 +871,7 @@ def add(
         classic: an (Optional) boolean specifying whether it should be added with classic
             confinement. Default `False`
         cohort: an (Optional) string specifying the snap cohort to use
-        revision: an (Optional) integer specifying the snap revision to use
+        revision: an (Optional) string specifying the snap revision to use
 
     Raises:
         SnapError if some snaps failed to install or were not found.
@@ -947,7 +947,7 @@ def _wrap_snap_operations(
     channel: str,
     classic: bool,
     cohort: Optional[str] = "",
-    revision: Optional[int] = None,
+    revision: Optional[str] = None,
 ) -> Union[Snap, List[Snap]]:
     """Wrap common operations for bare commands."""
     snaps = {"success": [], "failed": []}

pyproject.toml

@@ -66,6 +66,7 @@ optional = true
 
 [tool.poetry.group.relation_charm.dependencies]
 ops = "2.3.0"
+ops-lib-pgsql = "1.4"
 
 [build-system]
 requires = ["poetry-core>=1.0.0"]

renovate.json

@@ -36,7 +36,7 @@
       "extractVersionTemplate": "Juju release"
     }, {
       "fileMatch": ["(^|/)([\\w-]*)charmcraft\\.ya?ml$"],
-      "matchStrings": ["- (?<depName>.*?)==(?<currentValue>.*?) +# renovate"],
+      "matchStrings": ["- (?<depName>.*?)(?:\\[.*?\\])?==(?<currentValue>.*?) +# renovate"],
       "datasourceTemplate": "pypi",
       "versioningTemplate": "loose"
     }

requirements.txt

@@ -91,6 +91,6 @@ tenacity==8.2.2 ; python_full_version >= "3.8.10" and python_full_version < "4.0
 typing-extensions==4.6.3 ; python_full_version >= "3.8.10" and python_full_version < "4.0.0" \
     --hash=sha256:88a4153d8505aabbb4e13aacb7c486c2b4a33ca3b3f807914a9b4c844c471c26 \
     --hash=sha256:d91d5919357fe7f681a9f2b5b4cb2a5f1ef0a1e9f59c4d8ff0d3491e05c0ffd5
-websocket-client==1.6.1; python_full_version >= "3.8.10" and python_full_version < "4.0.0" \
+websocket-client==1.6.1 ; python_full_version >= "3.8.10" and python_full_version < "4.0.0" \
     --hash=sha256:c951af98631d24f8df89ab1019fc365f2227c0892f12fd150e935607c79dd0dd \
     --hash=sha256:f1f9f2ad5291f0225a49efad77abf9e700b6fef553900623060dad6e26503b9d

src/charm.py

@@ -13,7 +13,8 @@
 from typing import List, Optional, Union
 
 from charms.grafana_agent.v0.cos_agent import COSAgentProvider
-from charms.operator_libs_linux.v1 import snap, systemd
+from charms.operator_libs_linux.v1 import systemd
+from charms.operator_libs_linux.v2 import snap
 from charms.pgbouncer_k8s.v0 import pgb
 from jinja2 import Template
 from ops.charm import CharmBase
@@ -24,6 +25,7 @@
 from constants import (
     AUTH_FILE_NAME,
     CLIENT_RELATION_NAME,
+    EXTENSIONS_BLOCKING_MESSAGE,
     INI_NAME,
     MONITORING_PASSWORD_KEY,
     PEER_RELATION_NAME,
@@ -266,6 +268,9 @@ def check_status(self) -> Union[ActiveStatus, BlockedStatus, WaitingStatus]:
             logger.warning(backend_wait_msg)
             return BlockedStatus(backend_wait_msg)
 
+        if self.unit.status.message == EXTENSIONS_BLOCKING_MESSAGE:
+            return BlockedStatus(EXTENSIONS_BLOCKING_MESSAGE)
+
         prom_service = f"{PGB}-{self.app.name}-prometheus"
         services = [*self.pgb_services]
 

src/constants.py

@@ -12,7 +12,7 @@
 # Snap constants.
 PGBOUNCER_EXECUTABLE = "charmed-postgresql.pgbouncer"
 POSTGRESQL_SNAP_NAME = "charmed-postgresql"
-SNAP_PACKAGES = [(POSTGRESQL_SNAP_NAME, {"revision": 62})]
+SNAP_PACKAGES = [(POSTGRESQL_SNAP_NAME, {"revision": "62"})]
 
 SNAP_COMMON_PATH = "/var/snap/charmed-postgresql/common"
 SNAP_CURRENT_PATH = "/var/snap/charmed-postgresql/current"
@@ -33,3 +33,5 @@
 CLIENT_RELATION_NAME = "database"
 
 MONITORING_PASSWORD_KEY = "monitoring_password"
+
+EXTENSIONS_BLOCKING_MESSAGE = "bad relation request - remote app requested extensions, which are unsupported. Please remove this relation."

src/relations/db.py

@@ -85,7 +85,7 @@
 """  # noqa: W505
 
 import logging
-from typing import Dict, Iterable
+from typing import Dict, Iterable, List
 
 from charms.pgbouncer_k8s.v0 import pgb
 from charms.postgresql_k8s.v0.postgresql import (
@@ -111,7 +111,7 @@
     WaitingStatus,
 )
 
-from constants import PG
+from constants import EXTENSIONS_BLOCKING_MESSAGE, PG
 
 logger = logging.getLogger(__name__)
 
@@ -165,6 +165,34 @@ def __init__(self, charm: CharmBase, admin: bool = False):
         self.charm = charm
         self.admin = admin
 
+    def _check_extensions(self, extensions: List) -> bool:
+        """Checks if requested extensions are enabled."""
+        for extension in extensions:
+            extension_name = extension.split(":")[0]
+            if not self.charm.backend.database.is_postgresql_plugin_enabled(extension_name):
+                return False
+        return True
+
+    def _block_on_extensions(self, relation, remote_app_databag: Dict) -> bool:
+        """Verifies that extensions are enabled or blocks the charm."""
+        if "extensions" in remote_app_databag:
+            self.update_databags(
+                relation,
+                {
+                    "extensions": remote_app_databag["extensions"],
+                },
+            )
+            extensions = remote_app_databag["extensions"].split(",")
+            if not self._check_extensions(extensions):
+                # Do not allow apps requesting extensions to be installed.
+                logger.error(
+                    f"ERROR - `extensions` ({', '.join(extensions)}) cannot be requested through relations"
+                    " - Please enable extensions through `juju config` and add the relation again."
+                )
+                self.charm.unit.status = BlockedStatus(EXTENSIONS_BLOCKING_MESSAGE)
+                return True
+        return False
+
     def _on_relation_joined(self, join_event: RelationJoinedEvent):
         """Handle db-relation-joined event.
 
@@ -193,20 +221,7 @@ def _on_relation_joined(self, join_event: RelationJoinedEvent):
             join_event.defer()
             return
 
-        # Do not allow apps requesting extensions to be installed. Extensions should be installed
-        # through db charm config
-        if (
-            remote_app_databag.get("extensions") is not None
-            or remote_unit_databag.get("extensions") is not None
-        ):
-            logger.error(
-                "ERROR - `extensions` cannot be requested through relations"
-                " - they should be installed through a database charm config in the future"
-            )
-            self.charm.unit.status = BlockedStatus(
-                "bad relation request - remote app requested extensions, which are unsupported. Please remove this relation."
-            )
-            join_event.fail()
+        if self._block_on_extensions(join_event.relation, remote_app_databag):
             return
 
         user = self._generate_username(join_event)

tests/integration/relations/pgbouncer_provider/application-charm/metadata.yaml

@@ -17,3 +17,7 @@ requires:
     interface: postgresql_client
   multiple-database-clusters:
     interface: postgresql_client
+  db:
+    interface: pgsql
+    limit: 1
+    optional: true

tests/integration/relations/pgbouncer_provider/application-charm/requirements.txt

@@ -1,6 +1,12 @@
+ops-lib-pgsql==1.4 ; python_full_version >= "3.8.10" and python_full_version < "4.0.0" \
+    --hash=sha256:3ea802a1a9e6be4457dbe49959a76c50d63b689abc1b803c127bd24e5bd98654 \
+    --hash=sha256:85b07a364339da2423c2631680f03aab8f9b4d8a6493efc66303224ff9ab34af
 ops==2.3.0 ; python_full_version >= "3.8.10" and python_full_version < "4.0.0" \
     --hash=sha256:24a5c6e985d3f08cb3dfccfd1adb93ca9247dc867b192baaf3265fe5736fd992 \
     --hash=sha256:438c217be75f641948114bc24ecbb2adca2b5e407b401401e1b7dbc0f912731b
+pgconnstr==1.0.1 ; python_full_version >= "3.8.10" and python_full_version < "4.0.0" \
+    --hash=sha256:0656129961ae879675d0842f5237db82d31ce59c7b3211b051c33e37a864826e \
+    --hash=sha256:0f65830e7e3b76adf4390a8592ee52343171a17caef7436257e7bc81c44e21a7
 pyyaml==6.0 ; python_full_version >= "3.8.10" and python_full_version < "4.0.0" \
     --hash=sha256:01b45c0191e6d66c470b6cf1b9531a771a83c1c4208272ead47a3ae4f2f603bf \
     --hash=sha256:0283c35a6a9fbf047493e3a0ce8d79ef5030852c51e9d911a27badfde0605293 \
@@ -42,6 +48,6 @@ pyyaml==6.0 ; python_full_version >= "3.8.10" and python_full_version < "4.0.0"
     --hash=sha256:dbad0e9d368bb989f4515da330b88a057617d16b6a8245084f1b05400f24609f \
     --hash=sha256:e61ceaab6f49fb8bdfaa0f92c4b57bcfbea54c09277b1b4f7ac376bfb7a7c174 \
     --hash=sha256:f84fbc98b019fef2ee9a1cb3ce93e3187a6df0b2538a651bfb890254ba9f90b5
-websocket-client==1.6.1; python_full_version >= "3.8.10" and python_full_version < "4.0.0" \
+websocket-client==1.6.1 ; python_full_version >= "3.8.10" and python_full_version < "4.0.0" \
     --hash=sha256:c951af98631d24f8df89ab1019fc365f2227c0892f12fd150e935607c79dd0dd \
     --hash=sha256:f1f9f2ad5291f0225a49efad77abf9e700b6fef553900623060dad6e26503b9d