Add postgres cluster replication smoke tests.

tests/docker-postgres-replication/setup-replication.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+if [ "x$REPLICATE_FROM" == "x" ]; then
+
+cat >> ${PGDATA}/postgresql.conf <<EOF
+wal_level = hot_standby
+max_wal_senders = $PG_MAX_WAL_SENDERS
+wal_keep_segments = $PG_WAL_KEEP_SEGMENTS
+hot_standby = on
+EOF
+
+else
+
+cat > ${PGDATA}/recovery.conf <<EOF
+standby_mode = on
+primary_conninfo = 'host=${REPLICATE_FROM} port=5432 user=${POSTGRES_USER} password=${POSTGRES_PASSWORD}'
+trigger_file = '/tmp/touch_me_to_promote_to_me_master'
+EOF
+chown postgres ${PGDATA}/recovery.conf
+chmod 600 ${PGDATA}/recovery.conf
+
+fi