postgresql-pre-start hook example and test

- run 'initdb' from 'assemble', and bake the datadir into image
- install hook which extracts the tarball when data is not
  initialized

Fixes: sclorg#220

Author: praiskup

examples/s2i-dump-data/.s2i/bin/assemble

@@ -0,0 +1,36 @@
+#! /usr/bin/bash -x
+
+# fail early
+set -e
+
+# source the convenience tooling
+source "${CONTAINER_SCRIPTS_PATH}/common.sh"
+
+# set $PGDATA variable
+set_pgdata
+
+# assert uninitialized data
+test ! -f "$PGDATA/postgresql.conf"
+
+# empty config file is needed after 'initialize_database' call
+touch "$POSTGRESQL_CONFIG_FILE"
+
+initialize_database
+
+# start local PostgreSQL server (wait with '-w')
+pg_ctl -w start -o "-h ''"
+
+# load all sql files
+shopt -s nullglob
+for file in /tmp/src/init/*.sql; do
+    psql -f "$file"
+done
+
+pg_ctl stop
+
+# dump the data into $PWD (in-image storage)
+tar caf data.tar.xz -C "$PGDATA" .
+rm -rf "$PGDATA"
+
+# install pre-start hook
+cp -r /tmp/src/postgresql-pre-start .

examples/s2i-dump-data/init/init.sql

@@ -0,0 +1,2 @@
+CREATE TABLE test (sth TEXT);
+INSERT INTO test VALUES ('hello world');

examples/s2i-dump-data/postgresql-pre-start/10_boot.sh

@@ -0,0 +1,3 @@
+if test ! -f "$PGDATA/postgresql.conf"; then
+    tar xf "$APP_DATA"/src/data.tar.xz -C "$PGDATA"
+fi

test/run_test

@@ -26,6 +26,7 @@ run_master_restart_test
 run_doc_test
 run_s2i_test
 run_test_cfg_hook
+run_s2i_bake_data_test
 "
 
 test $# -eq 1 -a "${1-}" == --list && echo "$TEST_LIST" && exit 0
@@ -707,6 +708,25 @@ run_test_cfg_hook()
   assert_runtime_option "$name-3" shared_buffers 111MB
 }
 
+run_s2i_bake_data_test ()
+{
+  local s2i_image_name="$IMAGE_NAME-bake_$(ct_random_string)"
+  s2i build "file://$test_dir/../examples/s2i-dump-data" "${IMAGE_NAME}" "$s2i_image_name"
+  ct_path_append images_to_clean "$s2i_image_name"
+
+  local container_name=bake-data-test
+
+  DOCKER_ARGS="-e POSTGRESQL_ADMIN_PASSWORD=password" \
+    IMAGE_NAME="$s2i_image_name" create_container "$container_name"
+
+  wait_ready "$container_name"
+
+  test "hello world" == "$(docker exec "$(get_cid "$container_name")" \
+                           bash -c "psql -tA -c 'SELECT * FROM test;'")"
+
+  docker stop "$(get_cid "$container_name")"
+}
+
 function run_all_tests() {
   for test_case in $TEST_LIST; do
     : "Running test $test_case"