Prompt for PostgreSQL username and password instead of using configuration, and check that the user exists

scrolls/postgresql.rb

@@ -1,12 +1,25 @@
 gem "pg"
 
-gsub_file "config/database.yml", /username: .*/, "username: #{config['pg_username']}"
-gsub_file "config/database.yml", /password: .*/, "password: #{config['pg_password']}"
-
 after_bundler do
-  rake "db:create:all"
-
-  rakefile("sample.rake") do
+  require 'pg'
+
+  pg_username = ask_wizard "Local development PostgreSQL username:"
+  pg_password = ask_wizard "Local development PostgreSQL password:"
+
+  # attempt to connect to PostgreSQL using username and password
+  params = { :dbname => 'template1', :user => pg_username }
+  params[:password] = pg_password unless pg_password.blank?
+
+  begin
+    dbh = PG::Connection.new params
+    dbh.finish
+
+    gsub_file "config/database.yml", /username:\s?.*/, "username: #{pg_username}"
+    gsub_file "config/database.yml", /password:\s?.*/, "password: #{pg_password}"
+
+    rake "db:create:all"
+
+    rakefile("sample.rake") do
 <<-RUBY
 namespace :db do
   desc "Populate the database with sample data"
@@ -16,6 +29,11 @@
   task :populate => :sample
 end
 RUBY
+    end
+  rescue PG::Error => err
+    # surely there's a better way to report errors than this....
+    puts err.to_s
+    exit 1
   end
 end
 
@@ -31,11 +49,3 @@
 run_before: [eycloud]
 
 args: -d postgresql
-
-config:
-  - pg_username:
-      type: string
-      prompt: "Local development PostgreSQL username:"
-  - pg_password:
-      type: string
-      prompt: "Local development PostgreSQL password:"