From 383c2fe66570cb1a615654eb594d165ca455e964 Mon Sep 17 00:00:00 2001 From: Guillaume Boutry Date: Mon, 26 Feb 2024 14:42:18 +0100 Subject: [PATCH] Configure sysctl values from sunbeam-machine charm Move sysctl configure to the sunbeam-machine charms, this allows configuring the same set of values indepently from the machine provider. Added tests constraints to limits resource usage and ues virtual machines, as sysctl config modification in the container is usually banned by LXD. Change-Id: Ia0c66f14227f0d4c38735bb0d8e99f3868616305 --- charms/sunbeam-machine/src/charm.py | 29 ++ common.sh | 6 +- .../charms/operator_libs_linux/v0/sysctl.py | 288 ++++++++++++++++++ tests/machine/smoke.yaml.j2 | 2 + 4 files changed, 324 insertions(+), 1 deletion(-) create mode 100644 libs/external/lib/charms/operator_libs_linux/v0/sysctl.py diff --git a/charms/sunbeam-machine/src/charm.py b/charms/sunbeam-machine/src/charm.py index 5344eb7a..a46e8ab4 100755 --- a/charms/sunbeam-machine/src/charm.py +++ b/charms/sunbeam-machine/src/charm.py @@ -25,6 +25,10 @@ import logging import ops.framework import ops_sunbeam.charm as sunbeam_charm +import ops_sunbeam.guard as sunbeam_guard +from charms.operator_libs_linux.v0 import ( + sysctl, +) from ops.main import ( main, ) @@ -38,6 +42,31 @@ class SunbeamMachineCharm(sunbeam_charm.OSBaseOperatorCharm): _state = ops.framework.StoredState() service_name = "sunbeam-machine" + def __init__(self, framework: ops.Framework) -> None: + super().__init__(framework) + self.framework.observe(self.on.remove, self._on_remove) + self.sysctl = sysctl.Config(self.meta.name) + + def configure_unit(self, event: ops.EventBase): + """Run configuration on this unit.""" + super().configure_unit(event) + self._sysctl_configure() + + def _sysctl_configure(self): + """Run sysctl configuration on the local machine.""" + sysctl_data = {"fs.inotify.max_user_instances": "1024"} + try: + self.sysctl.configure(config=sysctl_data) + except (sysctl.ApplyError, sysctl.ValidationError): + logger.error("Error setting values on sysctl", exc_info=True) + raise sunbeam_guard.BlockedExceptionError("Sysctl config failed") + except sysctl.CommandError: + logger.error("Error executing sysctl", exc_info=True) + raise sunbeam_guard.BlockedExceptionError("Sysctl command failed") + + def _on_remove(self, event: ops.RemoveEvent): + self.sysctl.remove() + if __name__ == "__main__": # pragma: nocover main(SunbeamMachineCharm) diff --git a/common.sh b/common.sh index a4569ced..b274a8e6 100644 --- a/common.sh +++ b/common.sh @@ -147,6 +147,10 @@ EXTERNAL_SUNBEAM_CLUSTERD_LIBS=( "operator_libs_linux" ) +EXTERNAL_SUNBEAM_MACHINE_LIBS=( + "operator_libs_linux" +) + EXTERNAL_OVN_CENTRAL_LIBS=( "tls_certificates_interface" ) @@ -342,7 +346,7 @@ declare -A EXTERNAL_LIBS=( [openstack-exporter-k8s]=${EXTERNAL_OPENSTACK_EXPORTER_LIBS[@]} [openstack-hypervisor]=${EXTERNAL_OPENSTACK_HYPERVISOR_LIBS[@]} [sunbeam-clusterd]=${EXTERNAL_SUNBEAM_CLUSTERD_LIBS[@]} - [sunbeam-machine]=${NULL_ARRAY[@]} + [sunbeam-machine]=${EXTERNAL_SUNBEAM_MACHINE_LIBS[@]} [ovn-central-k8s]=${EXTERNAL_OVN_CENTRAL_LIBS[@]} [ovn-relay-k8s]=${EXTERNAL_OVN_RELAY_LIBS[@]} [placement-k8s]=${EXTERNAL_AODH_LIBS[@]} diff --git a/libs/external/lib/charms/operator_libs_linux/v0/sysctl.py b/libs/external/lib/charms/operator_libs_linux/v0/sysctl.py new file mode 100644 index 00000000..8245835e --- /dev/null +++ b/libs/external/lib/charms/operator_libs_linux/v0/sysctl.py @@ -0,0 +1,288 @@ +# Copyright 2023 Canonical Ltd. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +"""Handler for the sysctl config. + +This library allows your charm to create and configure sysctl options to the machine. + +Validation and merge capabilities are added, for situations where more than one application +are setting values. The following files can be created: + +- /etc/sysctl.d/90-juju- + Requirements from one application requesting to configure the values. + +- /etc/sysctl.d/95-juju-sysctl.conf + Merged file resulting from all other `90-juju-*` application files. + + +A charm using the sysctl lib will need a data structure like the following: +``` +{ +"vm.swappiness": "1", +"vm.max_map_count": "262144", +"vm.dirty_ratio": "80", +"vm.dirty_background_ratio": "5", +"net.ipv4.tcp_max_syn_backlog": "4096", +} +``` + +Now, it can use that template within the charm, or just declare the values directly: + +```python +from charms.operator_libs_linux.v0 import sysctl + +class MyCharm(CharmBase): + + def __init__(self, *args): + ... + self.sysctl = sysctl.Config(self.meta.name) + + self.framework.observe(self.on.install, self._on_install) + self.framework.observe(self.on.remove, self._on_remove) + + def _on_install(self, _): + # Altenatively, read the values from a template + sysctl_data = {"net.ipv4.tcp_max_syn_backlog": "4096"}} + + try: + self.sysctl.configure(config=sysctl_data) + except (sysctl.ApplyError, sysctl.ValidationError) as e: + logger.error(f"Error setting values on sysctl: {e.message}") + self.unit.status = BlockedStatus("Sysctl config not possible") + except sysctl.CommandError: + logger.error("Error on sysctl") + + def _on_remove(self, _): + self.sysctl.remove() +``` +""" + +import logging +import re +from pathlib import Path +from subprocess import STDOUT, CalledProcessError, check_output +from typing import Dict, List + +logger = logging.getLogger(__name__) + +# The unique Charmhub library identifier, never change it +LIBID = "17a6cd4d80104d15b10f9c2420ab3266" + +# Increment this major API version when introducing breaking changes +LIBAPI = 0 + +# Increment this PATCH version before using `charmcraft publish-lib` or reset +# to 0 if you are raising the major API version +LIBPATCH = 4 + +CHARM_FILENAME_PREFIX = "90-juju-" +SYSCTL_DIRECTORY = Path("/etc/sysctl.d") +SYSCTL_FILENAME = SYSCTL_DIRECTORY / "95-juju-sysctl.conf" +SYSCTL_HEADER = f"""# This config file was produced by sysctl lib v{LIBAPI}.{LIBPATCH} +# +# This file represents the output of the sysctl lib, which can combine multiple +# configurations into a single file like. +""" + + +class Error(Exception): + """Base class of most errors raised by this library.""" + + @property + def message(self): + """Return the message passed as an argument.""" + return self.args[0] + + +class CommandError(Error): + """Raised when there's an error running sysctl command.""" + + +class ApplyError(Error): + """Raised when there's an error applying values in sysctl.""" + + +class ValidationError(Error): + """Exception representing value validation error.""" + + +class Config(Dict): + """Represents the state of the config that a charm wants to enforce.""" + + _apply_re = re.compile(r"sysctl: permission denied on key \"([a-z_\.]+)\", ignoring$") + + def __init__(self, name: str) -> None: + self.name = name + self._data = self._load_data() + + def __contains__(self, key: str) -> bool: + """Check if key is in config.""" + return key in self._data + + def __len__(self): + """Get size of config.""" + return len(self._data) + + def __iter__(self): + """Iterate over config.""" + return iter(self._data) + + def __getitem__(self, key: str) -> str: + """Get value for key form config.""" + return self._data[key] + + @property + def charm_filepath(self) -> Path: + """Name for resulting charm config file.""" + return SYSCTL_DIRECTORY / f"{CHARM_FILENAME_PREFIX}{self.name}" + + def configure(self, config: Dict[str, str]) -> None: + """Configure sysctl options with a desired set of params. + + Args: + config: dictionary with keys to configure: + ``` + {"vm.swappiness": "10", ...} + ``` + """ + self._parse_config(config) + + # NOTE: case where own charm calls configure() more than once. + if self.charm_filepath.exists(): + self._merge(add_own_charm=False) + + conflict = self._validate() + if conflict: + raise ValidationError(f"Validation error for keys: {conflict}") + + snapshot = self._create_snapshot() + logger.debug("Created snapshot for keys: %s", snapshot) + try: + self._apply() + except ApplyError: + self._restore_snapshot(snapshot) + raise + + self._create_charm_file() + self._merge() + + def remove(self) -> None: + """Remove config for charm. + + The removal process won't apply any sysctl configuration. It will only merge files from + remaining charms. + """ + self.charm_filepath.unlink(missing_ok=True) + logger.info("Charm config file %s was removed", self.charm_filepath) + self._merge() + + def _validate(self) -> List[str]: + """Validate the desired config params against merged ones.""" + common_keys = set(self._data.keys()) & set(self._desired_config.keys()) + conflict_keys = [] + for key in common_keys: + if self._data[key] != self._desired_config[key]: + logger.warning( + "Values for key '%s' are different: %s != %s", + key, + self._data[key], + self._desired_config[key], + ) + conflict_keys.append(key) + + return conflict_keys + + def _create_charm_file(self) -> None: + """Write the charm file.""" + with open(self.charm_filepath, "w") as f: + f.write(f"# {self.name}\n") + for key, value in self._desired_config.items(): + f.write(f"{key}={value}\n") + + def _merge(self, add_own_charm=True) -> None: + """Create the merged sysctl file. + + Args: + add_own_charm : bool, if false it will skip the charm file from the merge. + """ + # get all files that start by 90-juju- + data = [SYSCTL_HEADER] + paths = set(SYSCTL_DIRECTORY.glob(f"{CHARM_FILENAME_PREFIX}*")) + if not add_own_charm: + paths.discard(self.charm_filepath) + + for path in paths: + with open(path, "r") as f: + data += f.readlines() + with open(SYSCTL_FILENAME, "w") as f: + f.writelines(data) + + # Reload data with newly created file. + self._data = self._load_data() + + def _apply(self) -> None: + """Apply values to machine.""" + cmd = [f"{key}={value}" for key, value in self._desired_config.items()] + result = self._sysctl(cmd) + failed_values = [ + self._apply_re.match(line) for line in result if self._apply_re.match(line) + ] + logger.debug("Failed values: %s", failed_values) + + if failed_values: + msg = f"Unable to set params: {[f.group(1) for f in failed_values]}" + logger.error(msg) + raise ApplyError(msg) + + def _create_snapshot(self) -> Dict[str, str]: + """Create a snapshot of config options that are going to be set.""" + cmd = ["-n"] + list(self._desired_config.keys()) + values = self._sysctl(cmd) + return dict(zip(list(self._desired_config.keys()), values)) + + def _restore_snapshot(self, snapshot: Dict[str, str]) -> None: + """Restore a snapshot to the machine.""" + values = [f"{key}={value}" for key, value in snapshot.items()] + self._sysctl(values) + + def _sysctl(self, cmd: List[str]) -> List[str]: + """Execute a sysctl command.""" + cmd = ["sysctl"] + cmd + logger.debug("Executing sysctl command: %s", cmd) + try: + return check_output(cmd, stderr=STDOUT, universal_newlines=True).splitlines() + except CalledProcessError as e: + msg = f"Error executing '{cmd}': {e.stdout}" + logger.error(msg) + raise CommandError(msg) + + def _parse_config(self, config: Dict[str, str]) -> None: + """Parse a config passed to the lib.""" + self._desired_config = {k: str(v) for k, v in config.items()} + + def _load_data(self) -> Dict[str, str]: + """Get merged config.""" + config = {} + if not SYSCTL_FILENAME.exists(): + return config + + with open(SYSCTL_FILENAME, "r") as f: + for line in f: + if line.startswith(("#", ";")) or not line.strip() or "=" not in line: + continue + + key, _, value = line.partition("=") + config[key.strip()] = value.strip() + + return config diff --git a/tests/machine/smoke.yaml.j2 b/tests/machine/smoke.yaml.j2 index 21fdc1e6..96dad237 100644 --- a/tests/machine/smoke.yaml.j2 +++ b/tests/machine/smoke.yaml.j2 @@ -7,6 +7,7 @@ applications: channel: 2023.2/edge {% endif -%} base: ubuntu@22.04 + constraints: cores=1 mem=1G virt-type=virtual-machine scale: 1 sunbeam-clusterd: {% if sunbeam_clusterd is defined and sunbeam_clusterd is sameas true -%} @@ -16,6 +17,7 @@ applications: channel: 2023.2/edge {% endif -%} base: ubuntu@22.04 + constraints: cores=1 mem=1G virt-type=virtual-machine scale: 1 options: # untrusted endpoints only on this branch