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AWS Elastic Beanstalk
Developer Guide (API Version 2010-12-01)

Configuring the Application Process with a Procfile

If you have more than one JAR file in the root of your application source bundle, you must include a Procfile file that tells Elastic Beanstalk which JAR(s) to run. You can also include a Procfile file for a single JAR application to configure the Java virtual machine (JVM) that runs your application.

You must save the Procfile in your source bundle root. The file name is case sensitive. Format the Procfile as follows: a process name, followed by a colon, followed by a Java command that runs a JAR. Each line in your Procfile must match the following regular expression: ^[A-Za-z0-9_]+:\s*.+$.

Procfile

web: java -jar server.jar -Xmms:256m
cache: java -jar mycache.jar
web_foo: java -jar other.jar

The command that runs the main JAR in your application must be called web, and it must be the first command listed in your Procfile. The nginx server forwards all HTTP requests that it receives from your environment's load balancer to this application.

By default, Elastic Beanstalk configures the nginx proxy to forward requests to your application on port 5000. You can override the default port by setting the PORT environment property to the port on which your main application listens.

Note

The port that your application listens on does not affect the port that the nginx server listens to receive requests from the load balancer.

If you use a Procfile to run multiple applications, Elastic Beanstalk expects each additional application to listen on a port 100 higher than the previous one. Elastic Beanstalk sets the PORT variable accessible from within each application to the port that it expects the application to run on. You can access this variable within your application code by calling System.getenv("PORT").

Note

In the preceding example, the web application listens on port 5000, cache listens on port 5100, and web_foo listens on port 5200. web configures its listening port by reading the PORT variable, and adds 100 to that number to determine which port cache is listening on so that it can send it requests.

Standard output and error streams from processes started with a Procfile are captured in log files named after the process and stored in /var/log. For example, the web process in the preceding example generates logs named web-1.log and web-1.error.log for stdout and stderr, respectively.

Elastic Beanstalk assumes that all entries in the Procfile should run at all times and automatically restarts any application defined in the Procfile that terminates. To run commands that will terminate and should not be restarted, use a Buildfile.