DPE-1799 Add rotation of mysqlrouter logs

.github/workflows/ci.yaml

@@ -45,8 +45,6 @@ jobs:
   build:
     name: Build charm
     uses: canonical/data-platform-workflows/.github/workflows/[email protected]
-    with:
-      charmcraft-snap-revision: 1349  # version 2.3.0
     permissions:
       actions: write  # Needed to manage GitHub Actions cache
 

.github/workflows/release.yaml

@@ -33,8 +33,6 @@ jobs:
   build:
     name: Build charm
     uses: canonical/data-platform-workflows/.github/workflows/[email protected]
-    with:
-      charmcraft-snap-revision: 1349  # version 2.3.0
 
   release:
     name: Release charm

charmcraft.yaml

@@ -22,6 +22,7 @@ parts:
     prime:
       - charm_version
       - workload_version
+      - scripts
     build-packages:
       - libffi-dev
       - libssl-dev

metadata.yaml

@@ -43,6 +43,6 @@ resources:
   mysql-router-image:
     type: oci-image
     description: OCI image for mysql-router
-    upstream-source: ghcr.io/canonical/charmed-mysql@sha256:3b6a4a63971acec3b71a0178cd093014a695ddf7c31d91d56ebb110eec6cdbe1
+    upstream-source: ghcr.io/canonical/charmed-mysql@sha256:0f5fe7d7679b1881afde24ecfb9d14a9daade790ec787087aa5d8de1d7b00b21
 assumes:
   - k8s-api

pyproject.toml

@@ -13,6 +13,7 @@ python = "^3.10"
 ops = "^2.6.0"
 lightkube = "^0.14.0"
 tenacity = "^8.2.3"
+jinja2 = "^3.1.2"
 poetry-core = "^1.7.0"
 
 [tool.poetry.group.charm-libs.dependencies]
@@ -57,6 +58,7 @@ pytest-operator-groups = {git = "https://github.com/canonical/data-platform-work
 juju = "^2.9.44.1"
 mysql-connector-python = "~8.0.33"
 pyyaml = "^6.0.1"
+tenacity = "^8.2.2"
 
 
 [tool.coverage.run]

scripts/logrotate_executor.py

@@ -0,0 +1,36 @@
+# Copyright 2023 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+"""Runs logrotate every minute."""
+
+import subprocess
+import time
+
+
+def main():
+    """Main watch and dispatch loop.
+
+    Roughly every 60s at the top of the minute, execute logrotate.
+    """
+    # wait till the top of the minute
+    time.sleep(60 - (time.time() % 60))
+    start_time = time.monotonic()
+
+    while True:
+        subprocess.run(
+            [
+                "logrotate",
+                "-f",
+                "-s",
+                "/tmp/logrotate.status",
+                "/etc/logrotate.d/flush_mysqlrouter_logs",
+            ],
+            check=True,
+        )
+
+        # wait again till the top of the next minute
+        time.sleep(60.0 - ((time.monotonic() - start_time) % 60.0))
+
+
+if __name__ == "__main__":
+    main()

src/abstract_charm.py

@@ -13,6 +13,7 @@
 
 import container
 import lifecycle
+import logrotate
 import relations.database_provides
 import relations.database_requires
 import upgrade
@@ -70,6 +71,11 @@ def _tls_certificate_saved(self) -> bool:
     def _container(self) -> container.Container:
         """Workload container (snap or ROCK)"""
 
+    @property
+    @abc.abstractmethod
+    def _logrotate(self) -> logrotate.LogRotate:
+        """logrotate"""
+
     @property
     @abc.abstractmethod
     def _upgrade(self) -> typing.Optional[upgrade.Upgrade]:
@@ -90,10 +96,11 @@ def get_workload(self, *, event):
         if connection_info := self._database_requires.get_connection_info(event=event):
             return self._authenticated_workload_type(
                 container_=self._container,
+                logrotate_=self._logrotate,
                 connection_info=connection_info,
                 charm_=self,
             )
-        return self._workload_type(container_=self._container)
+        return self._workload_type(container_=self._container, logrotate_=self._logrotate)
 
     @staticmethod
     # TODO python3.10 min version: Use `list` instead of `typing.List`

src/kubernetes_charm.py

@@ -17,7 +17,9 @@
 import ops
 
 import abstract_charm
+import kubernetes_logrotate
 import kubernetes_upgrade
+import logrotate
 import relations.tls
 import rock
 import upgrade
@@ -53,6 +55,10 @@ def tls_certificate_saved(self) -> bool:
     def _container(self) -> rock.Rock:
         return rock.Rock(unit=self.unit)
 
+    @property
+    def _logrotate(self) -> logrotate.LogRotate:
+        return kubernetes_logrotate.LogRotate(container_=self._container)
+
     @property
     def _upgrade(self) -> typing.Optional[kubernetes_upgrade.Upgrade]:
         try:

src/kubernetes_logrotate.py

@@ -0,0 +1,45 @@
+# Copyright 2023 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+"""logrotate implementation for k8s"""
+
+import logging
+import pathlib
+
+import container
+import logrotate
+
+logger = logging.getLogger(__name__)
+
+
+class LogRotate(logrotate.LogRotate):
+    """logrotate implementation for k8s"""
+
+    _SYSTEM_USER = "mysql"
+
+    def __init__(self, *, container_: container.Container):
+        super().__init__(container_=container_)
+        self._logrotate_executor = self._container.path("/logrotate_executor.py")
+
+    def enable(self) -> None:
+        super().enable()
+
+        logger.debug("Copying log rotate executor script to workload container")
+        self._logrotate_executor.write_text(
+            pathlib.Path("scripts/logrotate_executor.py").read_text()
+        )
+        logger.debug("Copied log rotate executor to workload container")
+
+        logger.debug("Starting the logrotate executor service")
+        self._container.update_logrotate_executor_service(enabled=True)
+        logger.debug("Started the logrotate executor service")
+
+    def disable(self) -> None:
+        logger.debug("Stopping the logrotate executor service")
+        self._container.update_logrotate_executor_service(enabled=False)
+        logger.debug("Stopped the logrotate executor service")
+
+        logger.debug("Removing logrotate config and executor files")
+        super().disable()
+        self._logrotate_executor.unlink()
+        logger.debug("Removed logrotate config and executor files")

src/logrotate.py

@@ -0,0 +1,50 @@
+# Copyright 2023 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+"""logrotate
+
+https://manpages.ubuntu.com/manpages/jammy/man8/logrotate.8.html
+"""
+
+import abc
+import logging
+import pathlib
+
+import jinja2
+
+import container
+
+logger = logging.getLogger(__name__)
+
+
+class LogRotate(abc.ABC):
+    """logrotate"""
+
+    def __init__(self, *, container_: container.Container):
+        self._container = container_
+
+        self._logrotate_config = self._container.path("/etc/logrotate.d/flush_mysqlrouter_logs")
+
+    @property
+    @abc.abstractmethod
+    def _SYSTEM_USER(self) -> str:  # noqa
+        """The system user that mysqlrouter runs as."""
+
+    def enable(self) -> None:
+        """Enable logrotate."""
+        logger.debug("Creating logrotate config file")
+
+        template = jinja2.Template(pathlib.Path("templates/logrotate.j2").read_text())
+
+        log_file_path = self._container.path("/var/log/mysqlrouter/mysqlrouter.log")
+        rendered = template.render(
+            log_file_path=str(log_file_path),
+            system_user=self._SYSTEM_USER,
+        )
+        self._logrotate_config.write_text(rendered)
+
+        logger.debug("Created logrotate config file")
+
+    def disable(self) -> None:
+        """Disable logrotate."""
+        self._logrotate_config.unlink()

src/rock.py

@@ -62,6 +62,7 @@ class Rock(container.Container):
     """Workload ROCK or OCI container"""
 
     _SERVICE_NAME = "mysql_router"
+    _LOGROTATE_EXECUTOR_SERVICE_NAME = "logrotate_executor"
 
     def __init__(self, *, unit: ops.Unit) -> None:
         super().__init__(mysql_router_command="mysqlrouter", mysql_shell_command="mysqlsh")
@@ -89,7 +90,6 @@ def update_mysql_router_service(self, *, enabled: bool, tls: bool = None) -> Non
             startup = ops.pebble.ServiceStartup.DISABLED.value
         layer = ops.pebble.Layer(
             {
-                "summary": "MySQL Router layer",
                 "services": {
                     self._SERVICE_NAME: {
                         "override": "replace",
@@ -110,6 +110,39 @@ def update_mysql_router_service(self, *, enabled: bool, tls: bool = None) -> Non
         else:
             self._container.stop(self._SERVICE_NAME)
 
+    def update_logrotate_executor_service(self, *, enabled: bool) -> None:
+        """Update and restart log rotate executor service.
+
+        Args:
+            enabled: Whether log rotate executor service is enabled
+        """
+        startup = (
+            ops.pebble.ServiceStartup.ENABLED.value
+            if enabled
+            else ops.pebble.ServiceStartup.DISABLED.value
+        )
+        layer = ops.pebble.Layer(
+            {
+                "services": {
+                    self._LOGROTATE_EXECUTOR_SERVICE_NAME: {
+                        "override": "replace",
+                        "summary": "Logrotate executor",
+                        "command": "python3 /logrotate_executor.py",
+                        "startup": startup,
+                        "user": _UNIX_USERNAME,
+                        "group": _UNIX_USERNAME,
+                    },
+                },
+            }
+        )
+        self._container.add_layer(self._LOGROTATE_EXECUTOR_SERVICE_NAME, layer, combine=True)
+        # `self._container.replan()` does not stop services that have been disabled
+        # Use `restart()` and `stop()` instead
+        if enabled:
+            self._container.restart(self._LOGROTATE_EXECUTOR_SERVICE_NAME)
+        else:
+            self._container.stop(self._LOGROTATE_EXECUTOR_SERVICE_NAME)
+
     # TODO python3.10 min version: Use `list` instead of `typing.List`
     def _run_command(self, command: typing.List[str], *, timeout: typing.Optional[int]) -> str:
         try:

src/workload.py

@@ -13,6 +13,7 @@
 import ops
 
 import container
+import logrotate
 import mysql_shell
 
 if typing.TYPE_CHECKING:
@@ -25,8 +26,11 @@
 class Workload:
     """MySQL Router workload"""
 
-    def __init__(self, *, container_: container.Container) -> None:
+    def __init__(
+        self, *, container_: container.Container, logrotate_: logrotate.LogRotate
+    ) -> None:
         self._container = container_
+        self._logrotate = logrotate_
         self._router_data_directory = self._container.path("/var/lib/mysqlrouter")
         self._tls_key_file = self._container.router_config_directory / "custom-key.pem"
         self._tls_certificate_file = (
@@ -56,6 +60,7 @@ def disable(self) -> None:
             return
         logger.debug("Disabling MySQL Router service")
         self._container.update_mysql_router_service(enabled=False)
+        self._logrotate.disable()
         self._container.router_config_directory.rmtree()
         self._container.router_config_directory.mkdir()
         self._router_data_directory.rmtree()
@@ -108,10 +113,11 @@ def __init__(
         self,
         *,
         container_: container.Container,
+        logrotate_: logrotate.LogRotate,
         connection_info: "relations.database_requires.ConnectionInformation",
         charm_: "abstract_charm.MySQLRouterCharm",
     ) -> None:
-        super().__init__(container_=container_)
+        super().__init__(container_=container_, logrotate_=logrotate_)
         self._connection_info = connection_info
         self._charm = charm_
 
@@ -218,6 +224,7 @@ def enable(self, *, tls: bool, unit_name: str) -> None:
             username=self._router_username, router_id=self._router_id, unit_name=unit_name
         )
         self._container.update_mysql_router_service(enabled=True, tls=tls)
+        self._logrotate.enable()
         logger.debug("Enabled MySQL Router service")
         self._charm.wait_until_mysql_router_ready()
 

templates/logrotate.j2

@@ -0,0 +1,29 @@
+# Use system user
+su {{ system_user }} {{ system_user }}
+
+# Create dedicated subdirectory for rotated files
+createolddir 770 {{ system_user }} {{ system_user }}
+
+# Frequency of logs rotation
+hourly
+maxage 7
+rotate 10800
+
+# Naming of rotated files should be in the format:
+dateext
+dateformat -%V_%H%M
+
+# Settings to prevent misconfigurations and unwanted behaviours
+ifempty
+missingok
+nocompress
+nomail
+nosharedscripts
+nocopytruncate
+
+{{ log_file_path }} {
+    olddir archive_mysqlrouter
+    postrotate
+        kill -HUP $(pidof mysqlrouter)
+    endscript
+}