CODEWITHSUNDEEP
javaakkatypesafe-config
ssukienn
ssukienn

Reputation: 588

Akka modifying/creating configuration file from source code

Is it possible to modify or create configuration file from source code. I am creating some client/server architecture with remoting. What I want to fulfill is ability to start client app with for example: host/port and when there is no configuration file yet to create one fulfilling the command line args.

akka {
  actor {
    provider = remote
  }
  remote {
    enabled-transports = ["akka.remote.netty.tcp"]
    netty.tcp {
      hostname = "127.0.0.1" <--- here 
      port = 2553 <--- here
    }
  }
}

Configs aren't really complicated. I want to change from source just port (eventually host, for now it is localhost anyway for tests) for automating it a bit so I can run multiple clients just by passing them to main function.

Upvotes: 2

Views: 1811

Answers (1)

Jeffrey Chung
Jeffrey Chung

Reputation: 19517

Yes, you can modify or create the configuration in the code. The following excerpts are from the Akka documentation:

An example of modifying a configuration programmatically:

// make a Config with just your special setting
Config myConfig = ConfigFactory.parseString("something=somethingElse");

// load the normal config stack (system props, then application.conf, then reference.conf)
Config regularConfig = ConfigFactory.load();

// override regular stack with myConfig
Config combined = myConfig.withFallback(regularConfig);

// put the result in between the overrides (system props) and defaults again
Config complete = ConfigFactory.load(combined);

// create ActorSystem
ActorSystem system = ActorSystem.create("myname", complete);

An example of creating a configuration programmatically (this is in Scala, but you can adapt it for Java):

import akka.actor.ActorSystem
import com.typesafe.config.ConfigFactory

val customConf = ConfigFactory.parseString("""
  akka.actor.deployment {
    /my-service {
      router = round-robin-pool
      nr-of-instances = 3
    }
  }
""")

// ConfigFactory.load sandwiches customConfig between default reference
// config and default overrides, and then resolves it.
val system = ActorSystem("MySystem", ConfigFactory.load(customConf))

Upvotes: 6

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