Extract managed-containerd proxy client

ocf/loxthelion/managed-container.d/proxy_client.py

@@ -0,0 +1,146 @@
+#!/usr/bin/env python3
+
+import json
+import socket
+import sys
+
+
+PROTOCOL_VERSION = 1
+VALID_OCF_RCS = {0, 1, 7, 8}
+
+
+def main():
+    if len(sys.argv) != 5:
+        raise SystemExit(11)
+
+    socket_path = sys.argv[1]
+    resource = sys.argv[2]
+    transport_failure = int(sys.argv[3])
+    protocol_failure = int(sys.argv[4])
+
+    request = {
+        "protocol_version": PROTOCOL_VERSION,
+        "action": "monitor",
+        "resource": resource,
+    }
+
+    try:
+        sock = socket.socket(
+            socket.AF_UNIX,
+            socket.SOCK_STREAM,
+        )
+        sock.settimeout(2.0)
+
+        try:
+            sock.connect(socket_path)
+
+            sock.sendall(
+                json.dumps(request).encode("utf-8")
+                + b"\n"
+            )
+
+            raw = b""
+
+            while b"\n" not in raw:
+                chunk = sock.recv(65536)
+
+                if not chunk:
+                    break
+
+                raw += chunk
+
+        finally:
+            sock.close()
+
+    except (
+        socket.timeout,
+        ConnectionError,
+        OSError,
+    ):
+        raise SystemExit(transport_failure)
+
+    # A connection was established. From this point onward, absence of a
+    # valid response is a protocol/result failure rather than transport loss.
+    if not raw:
+        raise SystemExit(protocol_failure)
+
+    try:
+        obj = json.loads(
+            raw.decode("utf-8").strip()
+        )
+
+    except (
+        UnicodeDecodeError,
+        json.JSONDecodeError,
+    ):
+        raise SystemExit(protocol_failure)
+
+    if not isinstance(obj, dict):
+        raise SystemExit(protocol_failure)
+
+    if obj.get("protocol_version") != PROTOCOL_VERSION:
+        raise SystemExit(protocol_failure)
+
+    if obj.get("ok") is not True:
+        raise SystemExit(protocol_failure)
+
+    if obj.get("resource") != resource:
+        raise SystemExit(protocol_failure)
+
+    if obj.get("action") != "monitor":
+        raise SystemExit(protocol_failure)
+
+    result = obj.get("result")
+
+    if not isinstance(result, dict):
+        raise SystemExit(protocol_failure)
+
+    ha = result.get("ha")
+
+    if not isinstance(ha, dict):
+        raise SystemExit(protocol_failure)
+
+    try:
+        ocf_rc = int(ha.get("ocf_rc"))
+
+    except (
+        TypeError,
+        ValueError,
+    ):
+        raise SystemExit(protocol_failure)
+
+    if ocf_rc not in VALID_OCF_RCS:
+        raise SystemExit(protocol_failure)
+
+    receiver = result.get("wal_receiver") or {}
+
+    if not isinstance(receiver, dict):
+        raise SystemExit(protocol_failure)
+
+    payload = "|".join([
+        str(ocf_rc),
+        str(ha.get("health", "unknown")),
+        str(ha.get("ha_role", "unknown")),
+        str(ha.get("state", "unknown")),
+        str(
+            ha.get(
+                "promotion_eligible",
+                "unknown",
+            )
+        ).lower(),
+        str(result.get("role", "unknown")),
+        str(
+            result.get(
+                "streaming",
+                "unknown",
+            )
+        ).lower(),
+        str(receiver.get("slot_name") or ""),
+        str(receiver.get("sender_host") or ""),
+    ])
+
+    print(payload)
+
+
+if __name__ == "__main__":
+    main()