The Play Framework understands that applications may require changes in configuration prior to deployment in production. To simplify deploying, the command to deploy the application also accepts application-level configurations as arguments:

[PlayScala] $ start -Dapplication.secret=S3CR3T
[info] Wrote /PlayScala/target/scala-2.10/playscala_2.10-1.0.pom

(Starting server. Type Ctrl+D to exit logs, the server will remain in background)
 
Play server process ID is 14904

Let's change the application's HTTP port as follows:

#setting http port to 1234
[PlayScala] $ start -Dhttp.port=1234

In some projects, the production and development configuration are maintained in two separate files. We could either pass one or more configurations or a different file altogether. There are three ways of specifying a configuration file explicitly. It can be achieved by using one of the following options: