§Deploying to Heroku
Heroku is a cloud application platform – a new way of building and deploying web apps.
To get started:
§Store your application in git
$ git init
$ git add .
$ git commit -m "init"
§Create a new application on Heroku
$ heroku create
Creating warm-frost-1289... done, stack is cedar
http://warm-1289.herokuapp.com/ | [email protected]:warm-1289.git
Git remote heroku added
This provisions a new application with an HTTP (and HTTPS) endpoint and Git endpoint for your application. The Git endpoint is set as a new remote named heroku
in your Git repository’s configuration.
§Deploy your application
To deploy your application on Heroku, just use git to push it into the heroku
remote repository:
$ git push heroku master
Counting objects: 34, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (20/20), done.
Writing objects: 100% (34/34), 35.45 KiB, done.
Total 34 (delta 0), reused 0 (delta 0)
-----> Heroku receiving push
-----> Scala app detected
-----> Building app with sbt v0.11.0
-----> Running: sbt clean compile stage
...
-----> Discovering process types
Procfile declares types -> web
-----> Compiled slug size is 46.3MB
-----> Launching... done, v5
http://8044.herokuapp.com deployed to Heroku
To [email protected]:floating-lightning-8044.git
* [new branch] master -> master
Heroku will run sbt clean compile stage
to prepare your application. On the first deployment, all dependencies will be downloaded, which takes a while to complete (but will be cached for future deployments).
§Check that your application has been deployed
Now, let’s check the state of the application’s processes:
$ heroku ps
Process State Command
------------ ------------------ ----------------------
web.1 up for 10s target/start
The web process is up. Review the logs for more information:
$ heroku logs
2011-08-18T00:13:41+00:00 heroku[web.1]: Starting process with command `target/start`
2011-08-18T00:14:18+00:00 app[web.1]: Starting on port:28328
2011-08-18T00:14:18+00:00 app[web.1]: Started.
2011-08-18T00:14:19+00:00 heroku[web.1]: State changed from starting to up
...
Looks good. We can now visit the app by running:
$ heroku open
§Connecting to a database
Heroku provides a number of relational an NoSQL databases through Heroku Add-ons. Play applications on Heroku are automatically provisioned a Heroku Postgres database. To configure your Play 2 application to use the Heroku Postgres database, first add the PostgreSQL JDBC driver to your application dependencies (project/Build.scala
):
"postgresql" % "postgresql" % "9.1-901-1.jdbc4"
Then create a new file in your project’s root directory named Procfile
(with a capital “P”) that contains the following:
web: target/start -Dhttp.port=${PORT} ${JAVA_OPTS} -DapplyEvolutions.default=true -Ddb.default.driver=org.postgresql.Driver -Ddb.default.url=${DATABASE_URL}
This instructs Heroku that for the process named web
it will run Play and override the applyEvolutions.default
, db.default.driver
, and db.default.url
configuration parameters. Note that the Procfile
command can be maximum 255 characters long. Alternatively, use the -Dconfig.resource=
or -Dconfig.file=
mentioned in production configuration page.