Add DETS migration script (#2522)

bin/migrate-dets.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+
+# This script is a wrapper around various flyway gradle tasks, and can be used to perform data migration against a named database in DETS.
+# The script requires the environment variables FLYWAY_USER and FLYWAY_PASSWORD to be set, and the executed tasks take their configuration from the flyway{}
+# block in the build.gradle file located in the project root.
+
+set -euo pipefail
+
+if [ -z "${FLYWAY_USER:-}" ]; then
+  echo "Env var FLYWAY_USER must be set"
+  exit 1
+fi
+
+if [ -z "${FLYWAY_PASSWORD:-}" ]; then
+  echo "Env var FLYWAY_PASSWORD must be set"
+  exit 1
+fi
+
+DATABASE_NAME=${1:-}
+if [ -z "$DATABASE_NAME" ]; then
+  echo "Usage: $0 <database_name>"
+  exit 1
+fi
+
+# Port 5433 is the local port that is mapped to the DB on the production bastion, per
+# https://tools.hmcts.net/confluence/display/DMP/Applying+Flyway+changes+to+Migration
+export FLYWAY_URL="jdbc:postgresql://localhost:5433/$DATABASE_NAME"
+
+cd ..
+./gradlew flywayInfo
+
+read -p 'Execute flywayMigrate? (y/n): ' continue
+if [ "$continue" != "y" ]
+then
+  exit 1
+fi
+
+./gradlew flywayMigrate
+./gradlew flywayValidate
+./gradlew flywayInfo