Proven working Postgresql monitor
This commit is contained in:
Lyncoln
@@ -0,0 +1,10 @@
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FROM registry.fedoraproject.org/fedora:44
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RUN dnf -y install \
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python3 \
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python3-psycopg2 \
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&& dnf clean all
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COPY daemon/ /opt/managed-containerd/daemon/
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ENTRYPOINT ["python3", "/opt/managed-containerd/daemon/server.py"]
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@@ -0,0 +1,174 @@
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#!/usr/bin/env python3
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import importlib.util
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import json
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import os
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from pathlib import Path
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class RegistryError(Exception):
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pass
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class Plugin:
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def __init__(self, plugin_root, name):
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self.name = name
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self.path = Path(plugin_root) / name
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self.manifest_path = self.path / "manifest.json"
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if not self.manifest_path.is_file():
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raise RegistryError(
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f"plugin manifest not found: {self.manifest_path}"
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)
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with self.manifest_path.open("r", encoding="utf-8") as f:
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self.manifest = json.load(f)
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module_name = self.manifest.get("module", "plugin.py")
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module_path = self.path / module_name
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if not module_path.is_file():
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raise RegistryError(
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f"plugin module not found: {module_path}"
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)
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spec = importlib.util.spec_from_file_location(
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f"managed_containerd_plugin_{name}",
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module_path,
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)
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if spec is None or spec.loader is None:
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raise RegistryError(
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f"unable to load plugin: {name}"
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)
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self.module = importlib.util.module_from_spec(spec)
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spec.loader.exec_module(self.module)
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@property
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def actions(self):
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return list(self.manifest.get("actions", []))
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@property
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def required_config(self):
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return list(
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self.manifest.get("required_config", [])
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)
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def validate_config(self, config):
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missing = [
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key
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for key in self.required_config
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if not config.get(key)
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]
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if missing:
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raise RegistryError(
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"missing required configuration: "
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+ ", ".join(missing)
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)
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def execute(self, action, config):
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if action not in self.actions:
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raise RegistryError(
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f"plugin {self.name} does not support action {action}"
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)
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handler = getattr(self.module, action, None)
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if handler is None:
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raise RegistryError(
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f"plugin {self.name} advertises {action} "
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"but does not implement it"
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)
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return handler(config)
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class Resource:
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def __init__(self, resource_id, plugin, config):
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self.resource_id = resource_id
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self.plugin = plugin
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self.config = config
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self.plugin.validate_config(config)
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def describe(self):
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return {
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"resource": self.resource_id,
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"plugin": self.plugin.name,
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"plugin_version": self.plugin.manifest.get(
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"version"
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),
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"actions": self.plugin.actions,
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"configured": True,
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}
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class Registry:
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def __init__(self):
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self.plugin_root = os.environ.get(
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"MANAGED_CONTAINERD_PLUGIN_ROOT",
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"/opt/managed-containerd/plugins",
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)
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self.resources = {}
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self._load_environment_resource()
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def _load_environment_resource(self):
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resource_id = os.environ.get("RESOURCE_ID")
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plugin_name = os.environ.get("PLUGIN")
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if not resource_id:
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raise RegistryError(
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"RESOURCE_ID is not configured"
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)
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if not plugin_name:
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raise RegistryError(
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"PLUGIN is not configured"
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)
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plugin = Plugin(
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self.plugin_root,
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plugin_name,
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)
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config = {
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key: os.environ.get(key)
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for key in plugin.required_config
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}
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self.resources[resource_id] = Resource(
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resource_id,
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plugin,
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config,
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)
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def list_resources(self):
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return {
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resource_id: resource.describe()
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for resource_id, resource
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in self.resources.items()
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}
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def execute(self, resource_id, action):
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resource = self.resources.get(resource_id)
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if resource is None:
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raise RegistryError(
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f"unknown resource: {resource_id}"
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)
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result = resource.plugin.execute(
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action,
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resource.config,
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)
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return {
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"ok": True,
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"resource": resource_id,
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"plugin": resource.plugin.name,
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"action": action,
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"result": result,
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}
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@@ -0,0 +1,165 @@
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#!/usr/bin/env python3
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import json
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import os
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import signal
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import socket
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import traceback
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from registry import Registry, RegistryError
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SOCKET_PATH = os.environ.get(
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"MANAGED_CONTAINERD_SOCKET",
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"/run/managed-containerd/managed-containerd.sock",
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)
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server_socket = None
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registry = None
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def handle_request(req):
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action = req.get("action")
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if action == "ping":
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return {
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"ok": True,
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"daemon": "managed-containerd",
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"protocol_version": 1,
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}
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if action == "registry.list":
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return {
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"ok": True,
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"resources": registry.list_resources(),
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}
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resource = req.get("resource")
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if not resource:
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return {
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"ok": False,
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"error": "resource is required",
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}
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return registry.execute(
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resource,
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action,
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)
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def cleanup_socket():
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try:
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os.unlink(SOCKET_PATH)
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except FileNotFoundError:
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pass
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def shutdown(signum, frame):
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global server_socket
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print(
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f"managed-containerd received signal {signum}; shutting down",
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flush=True,
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)
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if server_socket is not None:
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try:
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server_socket.close()
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except OSError:
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pass
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cleanup_socket()
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raise SystemExit(0)
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def serve():
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global server_socket
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global registry
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registry = Registry()
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os.makedirs(
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os.path.dirname(SOCKET_PATH),
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exist_ok=True,
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)
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cleanup_socket()
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signal.signal(signal.SIGTERM, shutdown)
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signal.signal(signal.SIGINT, shutdown)
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server_socket = socket.socket(
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socket.AF_UNIX,
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socket.SOCK_STREAM,
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)
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server_socket.bind(SOCKET_PATH)
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os.chmod(SOCKET_PATH, 0o660)
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server_socket.listen(16)
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print(
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f"managed-containerd listening on {SOCKET_PATH}",
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flush=True,
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)
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print(
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"registered resources: "
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+ ", ".join(registry.resources),
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flush=True,
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)
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try:
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while True:
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conn, _ = server_socket.accept()
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with conn:
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try:
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raw = b""
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while b"\n" not in raw:
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chunk = conn.recv(65536)
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if not chunk:
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break
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raw += chunk
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req = json.loads(
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raw.decode("utf-8").strip()
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)
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response = handle_request(req)
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except (
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RegistryError,
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ValueError,
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KeyError,
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) as exc:
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response = {
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"ok": False,
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"error": str(exc),
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}
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except Exception as exc:
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traceback.print_exc()
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response = {
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"ok": False,
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"error": str(exc),
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}
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conn.sendall(
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json.dumps(
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response,
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default=str,
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).encode("utf-8")
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+ b"\n"
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)
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finally:
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cleanup_socket()
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if __name__ == "__main__":
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serve()
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@@ -0,0 +1,15 @@
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{
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"name": "postgresql",
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"version": 1,
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"module": "plugin.py",
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"actions": [
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"monitor"
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],
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"required_config": [
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"PGHOST",
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"PGPORT",
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"PGUSER",
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"PGDATABASE",
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"PGPASSWORD_FILE"
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]
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}
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@@ -0,0 +1,139 @@
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#!/usr/bin/env python3
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import psycopg2
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import psycopg2.extras
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def read_secret(path):
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with open(path, "r", encoding="utf-8") as f:
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return f.read().strip()
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def monitor(config):
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password = read_secret(
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config["PGPASSWORD_FILE"]
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)
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conn = psycopg2.connect(
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host=config["PGHOST"],
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port=int(config["PGPORT"]),
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user=config["PGUSER"],
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dbname=config["PGDATABASE"],
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password=password,
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connect_timeout=5,
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application_name="managed-containerd",
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)
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try:
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conn.autocommit = True
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with conn.cursor(
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cursor_factory=psycopg2.extras.RealDictCursor
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) as cur:
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cur.execute("""
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SELECT pg_is_in_recovery() AS in_recovery
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""")
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in_recovery = bool(
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cur.fetchone()["in_recovery"]
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)
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if not in_recovery:
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cur.execute("""
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SELECT
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pg_current_wal_lsn()::text
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AS current_wal_lsn
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""")
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primary = cur.fetchone()
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else:
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primary = None
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if in_recovery:
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cur.execute("""
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SELECT
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pg_last_wal_receive_lsn()::text
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AS receive_lsn,
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pg_last_wal_replay_lsn()::text
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AS replay_lsn,
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pg_is_wal_replay_paused()
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AS replay_paused
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""")
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recovery = cur.fetchone()
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cur.execute("""
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SELECT
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status,
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sender_host,
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sender_port,
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slot_name,
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latest_end_lsn::text
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AS latest_end_lsn
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FROM pg_stat_wal_receiver
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LIMIT 1
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""")
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receiver = cur.fetchone()
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else:
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recovery = {
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"receive_lsn": None,
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"replay_lsn": None,
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"replay_paused": False,
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}
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receiver = None
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cur.execute("""
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SELECT
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current_setting('server_version')
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AS server_version,
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current_setting('cluster_name', true)
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AS cluster_name,
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current_user AS current_user,
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current_database()
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AS current_database,
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inet_server_addr()::text
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AS server_address,
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inet_server_port()
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AS server_port
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""")
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server = cur.fetchone()
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if in_recovery:
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role = "standby"
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streaming = bool(
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receiver
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and receiver.get("status")
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== "streaming"
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)
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|
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else:
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role = "primary"
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streaming = False
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return {
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"role": role,
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"in_recovery": in_recovery,
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"streaming": streaming,
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"wal_receiver": (
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dict(receiver)
|
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if receiver
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else None
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),
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"recovery": dict(recovery),
|
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"primary": (
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dict(primary)
|
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if primary
|
||||
else None
|
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),
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"server": dict(server),
|
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}
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finally:
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conn.close()
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@@ -0,0 +1,11 @@
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RESOURCE_ID=postgresql-ha
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PLUGIN=postgresql
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|
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MANAGED_CONTAINERD_SOCKET=/run/managed-containerd/managed-containerd.sock
|
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MANAGED_CONTAINERD_PLUGIN_ROOT=/opt/managed-containerd/plugins
|
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PGHOST=192.168.1.4
|
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PGPORT=5432
|
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PGUSER=david
|
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PGDATABASE=david
|
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PGPASSWORD_FILE=/run/secrets/postgres_password
|
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@@ -0,0 +1,255 @@
|
||||
#!/usr/bin/env python3
|
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|
||||
import json
|
||||
import os
|
||||
import signal
|
||||
import socket
|
||||
import traceback
|
||||
|
||||
import psycopg2
|
||||
import psycopg2.extras
|
||||
|
||||
|
||||
SOCKET_PATH = os.environ.get(
|
||||
"MANAGED_CONTAINERD_SOCKET",
|
||||
"/run/managed-containerd/managed-containerd.sock",
|
||||
)
|
||||
|
||||
PGHOST = os.environ.get("PGHOST", "postgres")
|
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PGPORT = int(os.environ.get("PGPORT", "5432"))
|
||||
PGUSER = os.environ.get("PGUSER", "david")
|
||||
PGDATABASE = os.environ.get("PGDATABASE", "david")
|
||||
PGPASSWORD_FILE = os.environ.get("PGPASSWORD_FILE")
|
||||
|
||||
server_socket = None
|
||||
|
||||
|
||||
def read_secret(path):
|
||||
if not path:
|
||||
return None
|
||||
|
||||
with open(path, "r", encoding="utf-8") as f:
|
||||
return f.read().strip()
|
||||
|
||||
|
||||
def postgres_status():
|
||||
password = read_secret(PGPASSWORD_FILE)
|
||||
|
||||
conn = psycopg2.connect(
|
||||
host=PGHOST,
|
||||
port=PGPORT,
|
||||
user=PGUSER,
|
||||
dbname=PGDATABASE,
|
||||
password=password,
|
||||
connect_timeout=5,
|
||||
application_name="managed-containerd",
|
||||
)
|
||||
|
||||
try:
|
||||
conn.autocommit = True
|
||||
|
||||
with conn.cursor(
|
||||
cursor_factory=psycopg2.extras.RealDictCursor
|
||||
) as cur:
|
||||
|
||||
#
|
||||
# Establish role first.
|
||||
#
|
||||
cur.execute("""
|
||||
SELECT pg_is_in_recovery() AS in_recovery
|
||||
""")
|
||||
in_recovery = bool(cur.fetchone()["in_recovery"])
|
||||
|
||||
#
|
||||
# Primary-only state.
|
||||
#
|
||||
if not in_recovery:
|
||||
cur.execute("""
|
||||
SELECT
|
||||
pg_current_wal_lsn()::text AS current_wal_lsn
|
||||
""")
|
||||
primary = cur.fetchone()
|
||||
else:
|
||||
primary = None
|
||||
|
||||
#
|
||||
# Recovery state.
|
||||
#
|
||||
if in_recovery:
|
||||
cur.execute("""
|
||||
SELECT
|
||||
pg_last_wal_receive_lsn()::text AS receive_lsn,
|
||||
pg_last_wal_replay_lsn()::text AS replay_lsn,
|
||||
pg_is_wal_replay_paused() AS replay_paused
|
||||
""")
|
||||
recovery = cur.fetchone()
|
||||
|
||||
cur.execute("""
|
||||
SELECT
|
||||
status,
|
||||
sender_host,
|
||||
sender_port,
|
||||
slot_name,
|
||||
latest_end_lsn::text AS latest_end_lsn
|
||||
FROM pg_stat_wal_receiver
|
||||
LIMIT 1
|
||||
""")
|
||||
receiver = cur.fetchone()
|
||||
|
||||
else:
|
||||
recovery = {
|
||||
"receive_lsn": None,
|
||||
"replay_lsn": None,
|
||||
"replay_paused": False,
|
||||
}
|
||||
receiver = None
|
||||
|
||||
#
|
||||
# General server state.
|
||||
#
|
||||
cur.execute("""
|
||||
SELECT
|
||||
current_setting('server_version') AS server_version,
|
||||
current_setting('cluster_name', true) AS cluster_name,
|
||||
current_user AS current_user,
|
||||
current_database() AS current_database,
|
||||
inet_server_addr()::text AS server_address,
|
||||
inet_server_port() AS server_port
|
||||
""")
|
||||
server = cur.fetchone()
|
||||
|
||||
if in_recovery:
|
||||
role = "standby"
|
||||
streaming = bool(
|
||||
receiver and receiver.get("status") == "streaming"
|
||||
)
|
||||
else:
|
||||
role = "primary"
|
||||
streaming = False
|
||||
|
||||
return {
|
||||
"ok": True,
|
||||
"application": "postgresql",
|
||||
"role": role,
|
||||
"in_recovery": in_recovery,
|
||||
"streaming": streaming,
|
||||
"wal_receiver": dict(receiver) if receiver else None,
|
||||
"recovery": dict(recovery),
|
||||
"primary": dict(primary) if primary else None,
|
||||
"server": dict(server),
|
||||
}
|
||||
|
||||
finally:
|
||||
conn.close()
|
||||
|
||||
|
||||
def handle_request(req):
|
||||
action = req.get("action")
|
||||
|
||||
if action == "ping":
|
||||
return {
|
||||
"ok": True,
|
||||
"daemon": "managed-containerd",
|
||||
"version": 1,
|
||||
}
|
||||
|
||||
if action == "postgresql.status":
|
||||
return postgres_status()
|
||||
|
||||
return {
|
||||
"ok": False,
|
||||
"error": f"unknown action: {action}",
|
||||
}
|
||||
|
||||
|
||||
def cleanup_socket():
|
||||
try:
|
||||
os.unlink(SOCKET_PATH)
|
||||
except FileNotFoundError:
|
||||
pass
|
||||
|
||||
|
||||
def shutdown(signum, frame):
|
||||
global server_socket
|
||||
|
||||
print(
|
||||
f"managed-containerd received signal {signum}; shutting down",
|
||||
flush=True,
|
||||
)
|
||||
|
||||
if server_socket is not None:
|
||||
try:
|
||||
server_socket.close()
|
||||
except OSError:
|
||||
pass
|
||||
|
||||
cleanup_socket()
|
||||
raise SystemExit(0)
|
||||
|
||||
|
||||
def serve():
|
||||
global server_socket
|
||||
|
||||
os.makedirs(os.path.dirname(SOCKET_PATH), exist_ok=True)
|
||||
cleanup_socket()
|
||||
|
||||
signal.signal(signal.SIGTERM, shutdown)
|
||||
signal.signal(signal.SIGINT, shutdown)
|
||||
|
||||
server_socket = socket.socket(
|
||||
socket.AF_UNIX,
|
||||
socket.SOCK_STREAM,
|
||||
)
|
||||
|
||||
server_socket.bind(SOCKET_PATH)
|
||||
os.chmod(SOCKET_PATH, 0o660)
|
||||
server_socket.listen(16)
|
||||
|
||||
print(
|
||||
f"managed-containerd listening on {SOCKET_PATH}",
|
||||
flush=True,
|
||||
)
|
||||
|
||||
try:
|
||||
while True:
|
||||
conn, _ = server_socket.accept()
|
||||
|
||||
with conn:
|
||||
try:
|
||||
raw = b""
|
||||
|
||||
while b"\n" not in raw:
|
||||
chunk = conn.recv(65536)
|
||||
|
||||
if not chunk:
|
||||
break
|
||||
|
||||
raw += chunk
|
||||
|
||||
req = json.loads(
|
||||
raw.decode("utf-8").strip()
|
||||
)
|
||||
|
||||
response = handle_request(req)
|
||||
|
||||
except Exception as exc:
|
||||
traceback.print_exc()
|
||||
|
||||
response = {
|
||||
"ok": False,
|
||||
"error": str(exc),
|
||||
}
|
||||
|
||||
conn.sendall(
|
||||
json.dumps(
|
||||
response,
|
||||
default=str,
|
||||
).encode("utf-8") + b"\n"
|
||||
)
|
||||
|
||||
finally:
|
||||
cleanup_socket()
|
||||
|
||||
|
||||
if __name__ == "__main__":
|
||||
serve()
|
||||
Reference in New Issue
Block a user