Heroku Review Apps: copy DB to review app

Question

Trying to fully automate Heroku's Review Apps (beta) for an app. Heroku wants us to use db/seeds.rb to seed the recently spun up instance's DB.

We don't have a db/seeds.rb with this app. We'd like to set up a script to copy the existing DB from the current parent (staging) and use that as the DB for the new app under review.

This I can do manually:

heroku pg:copy myapp::DATABASE_URL DATABASE_URL --app myapp-pr-1384 --confirm myapp-pr-1384

But I can't get figure out how to get the app name that Heroku creates into the postdeploy script.

Anyone tried this and know how it might be automated?

Answer 1

I ran into this same issue and here is how I solved it.

1. Set up the database url you want to copy from as an environment variable on the base app for the pipeline. In my case this is STAGING_DATABASE_URL. The url format is postgresql://username:password@host:port/db_name.

2. In your app.json file make sure to copy that variable over.

3. In your app.json provision a new database which will set the DATABASE_URL environment variable.

4. Use the following script to copy over the database pg_dump $STAGING_DATABASE_URL | psql $DATABASE_URL

Here is my app.json file for reference:

{
  "name": "app-name",
  "scripts": {
    "postdeploy": "pg_dump $STAGING_DATABASE_URL | psql $DATABASE_URL && bundle exec rake db:migrate"
  },
  "env": {
    "STAGING_DATABASE_URL": {
      "required": true
    },
    "HEROKU_APP_NAME": {
      "required": true
    }
  },
  "formation": {
    "web": {
      "quantity": 1,
      "size": "hobby"
    },
    "resque": {
      "quantity": 1,
      "size": "hobby"
    },
    "scheduler": {
      "quantity": 1,
      "size": "hobby"
    }
  },
  "addons": [
    "heroku-postgresql:hobby-basic",
    "papertrail",
    "rediscloud"
  ],
  "buildpacks": [
    {
      "url": "heroku/ruby"
    }
  ]
}

Answer 2

An alternative is to share the database between review apps. You can inherit DATABASE_URL in your app.json file.

PS: This is enough for my case which is a small team, keep in mind that maybe is not enough for yours. And, I keep my production and test (or staging, or dev, whatever you called it) data separated.

Answer 3

Alternatively: Another solution using pg_restore, thanks to https://gist.github.com/Kalagan/1adf39ffa15ae7a125d02e86ede04b6f

{
  "scripts": {
    "postdeploy": "pg_dump -Fc $DATABASE_URL_TO_COPY | pg_restore --clean --no-owner -n public -d $DATABASE_URL && bundle exec rails db:migrate"
  }
}