fix(rootfs): always perform an initial backup

When you complete a recovery of the database for the first time, a new log timeline is started with
an ID of 2. When you restore again (timeline of 3), the timeline used when the last backup occurred
will be replayed. Because of this, if you restored the database and did not perform a backup, all
data committed after that successful recovery will be lost because only WAL logs from the first
timeline (the timeline that the database was last backed up) will be restored.

In order to fix this, after completing a database recovery we create a fresh backup
in order to establish a new recovery baseline. That way we can now replay from
timeline 2.

Author: Matthew Fisher

rootfs/docker-entrypoint-initdb.d/003_restore_from_backup.sh

@@ -48,11 +48,11 @@ EOF
       -o "-c listen_addresses=''" \
       -t 1200 \
       -w start
-else
-  echo "No backups found. Performing an initial backup..."
-  gosu postgres envdir "$WALE_ENVDIR" wal-e backup-push "$PGDATA"
 fi
 
+echo "Performing an initial backup..."
+gosu postgres envdir "$WALE_ENVDIR" wal-e backup-push "$PGDATA"
+
 # ensure $PGDATA has the right permissions
 chown -R postgres:postgres "$PGDATA"
 chmod 0700 "$PGDATA"