added db migration script

scripts/migrate-db.sh

@@ -0,0 +1,134 @@
+#!/usr/bin/env bash
+
+usage() {
+  echo "  usage: $0 -e {cf-endpoint} -o {cf-org} -s {cf-space} -n {db-name} -p {db-plan} -a {app-name} [ -h (help)]"
+}
+
+error_exit() {
+  local msg="${1:-ERROR}"
+  echo "$msg"
+  exit 1
+}
+
+while getopts ":e:o:s:n:p:a:h" opt; do
+  case $opt in
+    e) cf_endpoint="$OPTARG" ;;
+    o) cf_org="$OPTARG" ;;
+    s) cf_space="$OPTARG" ;;
+    n) source_db_name="$OPTARG" ;;
+    p) target_db_plan="$OPTARG" ;;
+    a) app_name="$OPTARG" ;;
+    h) usage && exit 1 ;;
+    \?) error_exit "ERROR: invalid option --$OPTARG" ;;
+    :) error_exit "ERROR: option --$OPTARG requires an argument" ;;
+  esac
+done
+
+if [[ -z $cf_endpoint || -z $cf_org || -z $cf_space || -z $source_db_name || -z $target_db_plan || -z $app_name ]]; then
+  usage
+  error_exit "ERROR: missing arg(s)"
+fi
+
+uuid=$(uuidgen)
+source_db_rename="$source_db_name-MIGRATION_SOURCE_DB-$uuid"
+target_db_name="$source_db_name-MIGRATION_TARGET_DB-$uuid"
+pg_dump_file="$source_db_rename.pg_dump"
+
+if -f $pg_dump_file >/dev/null 2>&1; then
+  error_exit "ERROR: pg_dump file exists: $pg_dump_file"
+fi
+
+cf_endpoint_targeted=$(jq -r '.Target' < ~/.cf/config.json)
+if [[ "$cf_endpoint" != "$cf_endpoint_targeted" ]]; then
+  error_exit "ERROR: the currently targeted cf endpoint does not match the argument given at script invocation!"
+fi
+
+cf_org_targeted=$(jq -r '.OrganizationFields.Name' < ~/.cf/config.json)
+if [[ "$cf_org" != "$cf_org_targeted" ]]; then
+  error_exit "ERROR: the currently targeted cf org does not match the argument given at script invocation!"
+fi
+
+cf_space_targeted=$(jq -r '.SpaceFields.Name' < ~/.cf/config.json)
+if [[ "$cf_space" != "$cf_space_targeted" ]]; then
+  error_exit "ERROR: the currently targeted cf space does not match the argument given at script invocation!"
+fi
+
+if ! cf orgs >/dev/null 2>&1; then
+  error_exit "ERROR: no valid session for currently targetted cf env: $cf_endpoint"
+fi
+
+if ! cf service $source_db_name >/dev/null 2>&1; then
+  error_exit "ERROR: source db does not exist: $source_db_name"
+fi
+
+if cf service $source_db_rename >/dev/null 2>&1; then
+  error_exit "ERROR: service already exists with the migration temp name: $source_db_rename"
+fi
+
+if cf service $target_db_name >/dev/null 2>&1; then
+  echo "WARNING: target db already exists: $target_db_name"
+  read -r -p "Continue? (y/N): " confirm && [[ $confirm = "y" ]] || exit 1
+fi
+
+if ! cf app $app_name >/dev/null 2>&1; then
+  error_exit "ERROR: app does not exist: $app_name"
+fi
+
+echo "starting migration process..."
+
+echo "creating target db: $target_db_name..."
+if ! cf create-service -w postgres $target_db_plan $target_db_name >/dev/null 2>&1; then
+  error_exit
+fi
+
+echo "stopping app: $app_name..."
+if ! cf stop $app_name >/dev/null 2>&1; then
+  error_exit
+fi
+
+echo "renaming db: $source_db_name -> $source_db_rename..."
+if ! cf rename-service $source_db_name $source_db_rename >/dev/null 2>&1; then
+  error_exit
+fi
+
+echo "unbinding: $app_name -> $source_db_rename"
+if ! cf unbind-service $app_name $source_db_rename >/dev/null 2>&1; then
+  error_exit
+fi
+
+echo "starting pg_dump: $source_db_rename -> $pg_dump_file"
+if ! cf conduit $source_db_rename -- pg_dump --file $pg_dump_file --no-acl --no-owner >/dev/null 2>&1; then
+  error_exit
+fi
+
+echo "loading pg_dump data: $pg_dump_file -> $target_db_name"
+if ! cf conduit $target_db_name -- psql < $pg_dump_file >/dev/null 2>&1; then
+  error_exit
+fi
+
+echo "binding $app_name -> $target_db_name"
+if ! cf bind-service $app_name $target_db_name >/dev/null 2>&1; then
+  error_exit
+fi
+
+echo "renaming db: $target_db_name -> $source_db_name"
+if ! cf rename-service $target_db_name $source_db_name >/dev/null 2>&1; then
+  error_exit
+fi
+
+echo "starting app: $app_name"
+if ! cf start $app_name >/dev/null 2>&1; then
+  error_exit
+fi
+
+echo "deleting db: $source_db_rename"
+if ! cf delete-service -f $source_db_rename >/dev/null 2>&1; then
+  error_exit
+fi
+
+echo "deleting pg_dump file: $pg_dump_file"
+if ! rm -f $pg_dump_file >/dev/null 2>&1; then
+  error_exit
+fi
+
+echo "done."