K8SPG-628: Allow overriding restore_command

deploy/cr.yaml

@@ -469,6 +469,7 @@ spec:
 #    dynamicConfiguration:
 #      postgresql:
 #        parameters:
+#          restore_command: "pgbackrest --stanza=db archive-get %f \"%p\""
 #          max_parallel_workers: 2
 #          max_worker_processes: 2
 #          shared_buffers: 1GB

internal/pgbackrest/postgres.go

@@ -37,7 +37,14 @@ func PostgreSQL(
 	archive += ` if [ ! -z ${timestamp} ]; then echo ${timestamp} > /pgdata/latest_commit_timestamp.txt; fi`
 
 	outParameters.Mandatory.Add("archive_mode", "on")
-	outParameters.Mandatory.Add("archive_command", archive)
+
+	if backupsEnabled {
+		outParameters.Mandatory.Add("archive_command", archive)
+	} else {
+		// If backups are disabled, keep archive_mode on (to avoid a Postgres restart)
+		// and throw away WAL.
+		outParameters.Mandatory.Add("archive_command", `true`)
+	}
 
 	// K8SPG-518: This parameter is required to ensure that the commit timestamp is
 	// included in the WAL file. This is necessary for the WAL watcher to
@@ -63,6 +70,18 @@ func PostgreSQL(
 	// - https://pgbackrest.org/command.html#command-archive-get
 	// - https://www.postgresql.org/docs/current/runtime-config-wal.html
 	restore := `pgbackrest --stanza=` + DefaultStanzaName + ` archive-get %f "%p"`
+	if inCluster.Spec.Patroni != nil && inCluster.Spec.Patroni.DynamicConfiguration != nil {
+		postgresql, ok := inCluster.Spec.Patroni.DynamicConfiguration["postgresql"].(map[string]any)
+		if ok {
+			params, ok := postgresql["parameters"].(map[string]any)
+			if ok {
+				restore_command, ok := params["restore_command"].(string)
+				if ok {
+					restore = restore_command
+				}
+			}
+		}
+	}
 	outParameters.Mandatory.Add("restore_command", restore)
 
 	if inCluster.Spec.Standby != nil && inCluster.Spec.Standby.Enabled && inCluster.Spec.Standby.RepoName != "" {

internal/pgbackrest/postgres_test.go

@@ -39,10 +39,40 @@ func TestPostgreSQLParameters(t *testing.T) {
 		"archive_timeout": "60s",
 	})
 
+	dynamic := map[string]any{
+		"postgresql": map[string]any{
+			"parameters": map[string]any{
+				"restore_command": "/bin/true",
+			},
+		},
+	}
+	if cluster.Spec.Patroni == nil {
+		cluster.Spec.Patroni = &v1beta1.PatroniSpec{}
+	}
+	cluster.Spec.Patroni.DynamicConfiguration = dynamic
+
+	PostgreSQL(cluster, parameters, true)
+	assert.DeepEqual(t, parameters.Mandatory.AsMap(), map[string]string{
+		"archive_mode": "on",
+		"archive_command": strings.Join([]string{
+			`pgbackrest --stanza=db archive-push "%p" `,
+			`&& timestamp=$(pg_waldump "%p" | `,
+			`grep -oP "COMMIT \K[^;]+" | `,
+			`sed -E "s/([0-9]{4}-[0-9]{2}-[0-9]{2}) ([0-9]{2}:[0-9]{2}:[0-9]{2}\.[0-9]{6}) (UTC|[\\+\\-][0-9]{2})/\1T\2\3/" | `,
+			`sed "s/UTC/Z/" | `,
+			"tail -n 1 | ",
+			`grep -E "^[0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}\.[0-9]{6}(Z|[\+\-][0-9]{2})$"); `,
+			"if [ ! -z ${timestamp} ]; then echo ${timestamp} > /pgdata/latest_commit_timestamp.txt; fi",
+		}, ""),
+		"restore_command":        "/bin/true",
+		"track_commit_timestamp": "true",
+	})
+
 	cluster.Spec.Standby = &v1beta1.PostgresStandbySpec{
 		Enabled:  true,
 		RepoName: "repo99",
 	}
+	cluster.Spec.Patroni.DynamicConfiguration = nil
 
 	PostgreSQL(cluster, parameters, true)
 	assert.DeepEqual(t, parameters.Mandatory.AsMap(), map[string]string{