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dockerlocalhostgatlingconnection-refused

Connecting from gatling simulation inside Docker to localhost

I am trying to test my localhost service using Gatling inside Docker using MacOS.

I run Docker using: 

  docker run -it -d --rm \
    --network="host" \
    -v $(PWD)/conf:/opt/gatling/conf \
    -v $(PWD)/user-files:/opt/gatling/user-files \
    -v $(PWD)/results:/opt/gatling/results \
    --name $CONTAINER_NAME $IMAGE_NAME

Afaik using '--host' enables using host network from inside Docker.

My service runs o port 9000, so my base url in Gatling, so I define it like that:

  private val baseUrl = "http://127.0.0.1:9000"
  private val httpProtocol = http
    .baseUrl(baseUrl)

Although I keep getting: 

AbstractChannel$AnnotatedConnectException: Connection refused: /127.0.0.1:9000

Is there an issue with my config, or Gatling limitation?

Solution

  • Change the host address from http://127.0.0.1 to host.docker.internal and it should work.

    In essence host.docker.internal will returns the IP for our docker host. But this feature only exists in Docker for Mac OSX & Docker for Windows. You could read more about this feature here:

    https://docs.docker.com/docker-for-mac/networking/

    https://docs.docker.com/docker-for-windows/networking/.