prometheus_keepalived: add role

roles/prometheus_keepalived/files/prometheus-keepalived

@@ -0,0 +1,66 @@
+#!/usr/bin/env python3
+import argparse
+import asyncio
+
+from dbus_next import InterfaceNotFoundError
+from dbus_next.aio import MessageBus
+from dbus_next.constants import BusType
+from dbus_next.introspection import Node
+from prometheus_client import CollectorRegistry, Enum, write_to_textfile
+
+
+def patch(introspect):
+    xml = introspect.to_xml()
+    name = xml.find(
+        'interface[@name="org.keepalived.Vrrp1.Instance"]'
+        '/property[@name="Name"]'
+    )
+    if name is not None:
+        name.attrib["type"] = "(s)"
+    return Node.from_xml(xml, is_root=True)
+
+
+async def traverse(bus, path="/org/keepalived/Vrrp1/Instance"):
+
+    introspect = patch(await bus.introspect("org.keepalived.Vrrp1", path))
+    proxy = bus.get_proxy_object("org.keepalived.Vrrp1", path, introspect)
+
+    try:
+        interface = proxy.get_interface("org.keepalived.Vrrp1.Instance")
+        _, state = await interface.get_state()
+        (name,) = await interface.get_name()
+        yield name, state
+    except InterfaceNotFoundError:
+        pass
+
+    for path in proxy.child_paths:
+        async for state in traverse(bus, path):
+            yield state
+
+
+async def main():
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument("filename")
+
+    args = parser.parse_args()
+
+    bus = await MessageBus(bus_type=BusType.SYSTEM).connect()
+
+    registry = CollectorRegistry()
+    enum = Enum(
+        "keepalived_vrrp_state",
+        "Keepalived VRRP state",
+        ["name"],
+        registry=registry,
+        states=("stop", "init", "backup", "master", "fault", "deleted"),
+    )
+
+    async for name, state in traverse(bus):
+        enum.labels(name=name).state(state.lower())
+
+    write_to_textfile(args.filename, registry)
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

roles/prometheus_keepalived/handlers/main.yml

@@ -0,0 +1,5 @@
+---
+- name: Run daemon-reload
+  systemd:
+    daemon_reload: true
+...

roles/prometheus_keepalived/tasks/main.yml

@@ -0,0 +1,34 @@
+---
+- name: Install dependencies
+  apt:
+    name:
+      - python3-prometheus-client
+      - python3-dbus-next
+
+- name: Install prometheus-keepalived
+  copy:
+    src: prometheus-keepalived
+    dest: /usr/local/bin/prometheus-keepalived
+    mode: u=rwx,g=rx,o=rx
+    owner: root
+    group: root
+
+- name: Configure prometheus-keepalived timer
+  template:
+    src: "{{ item }}.j2"
+    dest: "/etc/systemd/system/{{ item }}"
+    mode: u=rw,g=r,o=r
+    owner: root
+    group: root
+  loop:
+    - prometheus-keepalived.service
+    - prometheus-keepalived.timer
+  notify:
+    - Run daemon-reload
+
+- name: Enable prometheus-keepalived timer
+  systemd:
+    name: prometheus-keepalived.timer
+    enabled: true
+    state: started
+...

roles/prometheus_keepalived/templates/prometheus-keepalived.service.j2

@@ -0,0 +1,10 @@
+{{ ansible_managed | comment }}
+
+[Unit]
+Description=Prometheus Keepalived
+
+[Service]
+Type=oneshot
+User=prometheus
+Group=prometheus
+ExecStart=/usr/local/bin/prometheus-keepalived {{ prometheus_keepalived__dest | enquote }}

roles/prometheus_keepalived/templates/prometheus-keepalived.timer.j2

@@ -0,0 +1,10 @@
+{{ ansible_managed | comment }}
+
+[Unit]
+Description=Timer for Prometheus Keepalived
+
+[Timer]
+OnUnitActiveSec=15s
+
+[Install]
+WantedBy=timers.target