move seed script to ruby, make it more responsive to db changes (#821)

Previous version of this script did not handle engine migrations and
would get the wrong count pretty easily.

bin/db-migrate-seed.sh

@@ -1,17 +1,67 @@
-#!/bin/sh
-set -e
-
-db-wait.sh "$DB_HOST:$DB_PORT"
-if [ "$FCREPO_HOST" ]; then
-    db-wait.sh "$FCREPO_HOST:$FCREPO_PORT"
-fi
-db-wait.sh "$SOLR_HOST:$SOLR_PORT"
-
-migrations_run=`PGPASSWORD=$DATABASE_PASSWORD psql -h $DATABASE_HOST -U $DATABASE_USER $DATABASE_NAME -t -c "SELECT version FROM schema_migrations ORDER BY schema_migrations" | wc -c`
-migrations_fs=`ls -l db/migrate/ | awk '{print $9}' | grep -o '[0-9]\+' | wc -c`
-echo "relation 'schema migrations' does not exist will be printed when the db hasn't been created yet."
-if [[ "$migrations_run" -lt "$migrations_fs" ]]; then
-    bundle exec rails db:create
-    bundle exec rails db:migrate
-    bundle exec rails db:seed
-fi
+#!/usr/bin/env ruby
+
+require 'open3'
+require 'bundler'
+
+def db_wait(address)
+  system("db-wait.sh #{address}")
+end
+
+def run_command(command)
+  stdout, stderr, status = Open3.capture3(command)
+  raise stderr unless status.success?
+  stdout
+end
+
+def migrations_list(query)
+  result = run_command(query)
+  result.split("\n").map(&:strip).reject(&:empty?)
+end
+
+def bundled_migrations
+  migration_list = Bundler.load.specs.inject([]) do |arr, spec|
+    if File.exist?("#{spec.full_gem_path}/lib/*/engine.rb")
+      migrations = Dir.glob("#{spec.full_gem_path}/db/migrate/*")
+      migrations.each do |migration_path|
+        arr.push(File.basename(migration_path).split('_').first)
+      end
+    end
+    arr
+  end
+  Dir.glob('db/migrate/*.rb').each do |migration_path|
+    migration_list.push(File.basename(migration_path).split('_').first)
+  end
+  migration_list
+end
+
+begin
+  db_host = ENV['DB_HOST']
+  db_port = ENV['DB_PORT']
+  fcrepo_host = ENV['FCREPO_HOST']
+  fcrepo_port = ENV['FCREPO_PORT']
+  solr_host = ENV['SOLR_HOST']
+  solr_port = ENV['SOLR_PORT']
+  db_user = ENV['DB_USER']
+  db_name = ENV['DB_NAME']
+  db_password = ENV['DB_PASSWORD']
+
+  db_wait("#{db_host}:#{db_port}")
+  db_wait("#{fcrepo_host}:#{fcrepo_port}") if fcrepo_host
+  db_wait("#{solr_host}:#{solr_port}")
+
+  migrations_run_query = "PGPASSWORD=#{db_password} psql -h #{db_host} -U #{db_user} #{db_name} -t -c \"SELECT version FROM schema_migrations ORDER BY schema_migrations\""
+  migrations_run = migrations_list(migrations_run_query)
+
+  migrations_fs = bundled_migrations
+
+  if (migrations_fs - migrations_run).size > 0
+    run_command('bundle exec rails db:create')
+    run_command('bundle exec rails db:migrate')
+    run_command('bundle exec rails db:seed')
+  end
+rescue => e
+  puts "An error occurred: #{e.message}"
+  exit 1
+end
+
+puts 'all migrations have been run'