K8SPG-681: Improve latest restorable time detection

Author: egegunes

internal/pgbackrest/postgres.go

@@ -28,12 +28,13 @@ func PostgreSQL(
 	// - https://pgbackrest.org/user-guide.html#quickstart/configure-archiving
 	// - https://pgbackrest.org/command.html#command-archive-push
 	// - https://www.postgresql.org/docs/current/runtime-config-wal.html
-	fixTimezone := `sed -E 's/([0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}\.[0-9]{6}) (UTC|[\+\-][0-9]{2})/\1\2/' | sed 's/UTC/Z/'`
-	extractCommitTime := `awk '{print $(NF-2) "T" $(NF-1) " " $(NF)}' | ` + fixTimezone + ``
-	validateCommitTime := `grep -E '^[0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}\.[0-9]{6}(Z|[\+\-][0-9]{2}`
+
+	fixTimezone := `sed -E "s/([0-9]{4}-[0-9]{2}-[0-9]{2}) ([0-9]{2}:[0-9]{2}:[0-9]{2}\.[0-9]{6}) (UTC|[\\+\\-][0-9]{2})/\1T\2\3/" | sed "s/UTC/Z/"`
+	extractCommitTime := `grep -oP "COMMIT \K[^;]+" | ` + fixTimezone + ``
+	validateCommitTime := `grep -E "^[0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}\.[0-9]{6}(Z|[\+\-][0-9]{2})$"`
 	archive := `pgbackrest --stanza=` + DefaultStanzaName + ` archive-push "%p"`
-	archive += ` && timestamp=$(pg_waldump "%p" | grep COMMIT | ` + extractCommitTime + ` | tail -n 1 | ` + validateCommitTime + `)$');`
-	archive += ` if [ ! -z ${timestamp} ]; then echo ${timestamp} > /pgdata/latest_commit_timestamp.txt; fi`
+	archive += ` && timestamp=$(pg_waldump "%p" | ` + extractCommitTime + ` | tail -n 1 | ` + validateCommitTime + `);`
+	archive += ` if [ ! -z ${timestamp} ]; then echo ${timestamp} > /pgdata/latest_commit_timestamp.txt; else echo "failed" > /pgdata/commit_ts_error.txt; fi`
 
 	outParameters.Mandatory.Add("archive_mode", "on")
 	outParameters.Mandatory.Add("archive_command", archive)