Handle PostgreSQL self-restart demotion preflight

plugins/postgresql/plugin.py

@@ -802,6 +802,47 @@ def demote_prepare(config, runtime_state, request_parameters):
             "successor_node": successor_node,
         }
 
+    promoted_nodes = {
+        str(name).strip().lower()
+        for name in str(
+            notification.get("promoted_uname", "")
+        ).split()
+        if str(name).strip()
+    }
+
+    if successor_node == node_name:
+        if node_name not in promoted_nodes:
+            return {
+                "ocf_rc": 1,
+                "ready": False,
+                "reason": "self_restart_not_current_primary",
+                "node": node_name,
+                "target_node": target_node,
+                "successor_node": successor_node,
+            }
+
+        return {
+            "ocf_rc": 0,
+            "ready": False,
+            "identity_validated": True,
+            "reason": "local_restart_checks_pending",
+            "mutation": False,
+            "node": node_name,
+            "target_node": target_node,
+            "successor_node": successor_node,
+            "handoff_mode": "local_restart",
+            "final_handoff_required": False,
+            "age_seconds": age,
+            "checks": {
+                "notification": True,
+                "local_target": True,
+                "self_successor": True,
+                "local_currently_promoted": True,
+                "postgresql_mutated": False,
+                "database_checks": False,
+            },
+        }
+
     if not successor_node:
         return {
             "ocf_rc": 1,
@@ -885,6 +926,7 @@ def demote_database(config, runtime_state, request_parameters):
 
     if preparation.get("reason") not in (
         "database_checks_pending",
+        "local_restart_checks_pending",
     ):
         return preparation
 
@@ -898,6 +940,26 @@ def demote_database(config, runtime_state, request_parameters):
             "local": local["ha"],
         }
 
+    if preparation.get("reason") == "local_restart_checks_pending":
+        return {
+            "ocf_rc": 0,
+            "ready": True,
+            "mutation": False,
+            "final_handoff_required": False,
+            "handoff_mode": "local_restart",
+            "reason": "local_restart_demotion_ready",
+            "node": preparation["node"],
+            "target_node": preparation["target_node"],
+            "successor_node": preparation["successor_node"],
+            "checks": {
+                "notification": True,
+                "local_target": True,
+                "local_primary": True,
+                "self_successor": True,
+                "remote_handoff_required": False,
+            },
+        }
+
     successor_node = preparation["successor_node"]
     peers = parse_replication_peers(
         config.get("PG_REPLICATION_PEERS", "")

tests/test-demote-database.py

@@ -137,3 +137,56 @@ assert result["reason"] == "successor_unreachable"
 print("successor_unreachable    rejected")
 
 print("DEMOTE_DATABASE_FAILURE_TEST_PASS=1")
+
+print()
+print("===== SELF-RESTART DATABASE GATE =====")
+
+plugin.monitor = lambda config, runtime_state: {
+    "ha": {"ocf_rc": plugin.OCF_RUNNING_PROMOTED},
+    "primary": {"current_wal_lsn": "14/1C07A920"},
+}
+
+self_restart_state = {
+    "postgresql": {
+        "notification": {
+            "type": "pre",
+            "operation": "demote",
+            "demote_uname": "david-prodesk",
+            "promote_uname": "david-prodesk",
+            "promoted_uname": "david-prodesk",
+            "unpromoted_uname": "david-eve",
+            "received_at": time.time(),
+        },
+    },
+}
+
+connect_called = False
+
+def must_not_connect(**kwargs):
+    global connect_called
+    connect_called = True
+    raise AssertionError(
+        "self-restart demotion must not probe a remote successor"
+    )
+
+plugin.psycopg2.connect = must_not_connect
+
+result = plugin.demote_database(
+    config,
+    self_restart_state,
+    {},
+)
+
+assert result["ocf_rc"] == 0
+assert result["ready"] is True
+assert result["mutation"] is False
+assert result["final_handoff_required"] is False
+assert result["handoff_mode"] == "local_restart"
+assert result["reason"] == "local_restart_demotion_ready"
+assert result["successor_node"] == "david-prodesk"
+assert result["checks"]["local_primary"] is True
+assert result["checks"]["remote_handoff_required"] is False
+assert connect_called is False
+
+print("self_restart_database     accepted")
+print("remote_probe_skipped      accepted")

tests/test-demote-prepare.py

@@ -124,3 +124,63 @@ result = plugin.demote_prepare(
 assert result["ocf_rc"] == 1
 assert result["reason"] == "successor_not_configured"
 print("unconfigured_successor  rejected")
+
+print()
+print("===== SELF-RESTART PREPARE =====")
+
+self_restart_state = {
+    "postgresql": {
+        "notification": {
+            "type": "pre",
+            "operation": "demote",
+            "demote_uname": "david-eve",
+            "promote_uname": "david-eve",
+            "promoted_uname": "david-eve",
+            "unpromoted_uname": "david-prodesk david-macbookpro",
+            "received_at": time.time(),
+        },
+    },
+}
+
+result = plugin.demote_prepare(
+    {
+        "PACEMAKER_NODE_NAME": "david-eve",
+        "PG_REPLICATION_PEERS": (
+            "david-prodesk=192.168.1.4:5432,"
+            "david-eve=192.168.1.3:5432"
+        ),
+    },
+    self_restart_state,
+    {},
+)
+
+assert result["ocf_rc"] == 0
+assert result["ready"] is False
+assert result["identity_validated"] is True
+assert result["reason"] == "local_restart_checks_pending"
+assert result["handoff_mode"] == "local_restart"
+assert result["final_handoff_required"] is False
+assert result["successor_node"] == "david-eve"
+assert result["checks"]["self_successor"] is True
+assert result["checks"]["local_currently_promoted"] is True
+
+print("self_restart_prepare      accepted")
+
+self_restart_state["postgresql"]["notification"]["promoted_uname"] = ""
+
+result = plugin.demote_prepare(
+    {
+        "PACEMAKER_NODE_NAME": "david-eve",
+        "PG_REPLICATION_PEERS": (
+            "david-prodesk=192.168.1.4:5432,"
+            "david-eve=192.168.1.3:5432"
+        ),
+    },
+    self_restart_state,
+    {},
+)
+
+assert result["ocf_rc"] == 1
+assert result["reason"] == "self_restart_not_current_primary"
+
+print("false_self_restart        rejected")