nomad job spec 'count', how to reference in instance?

[Greg Fausak]

Probably a dumb question :-) If I am running a job with count=2, from the job instance point of view, how do i know which job i am (1 or 2)??

-g

[Sébastien Portebois]

Hi Greg

I'm not sure about the job count. What I use is the group count (how many replicas of this group should run)

For that group, each group allocation got an index, which you can access from the NOMAD_ALLOC_INDEX env variable. 

Here's a simple http-echo job which would echo them (because I'm too lazy to use an exec then fetch the logs)

job "show-count" {

  type = "service"

  datacenters = ["us-east-1a", "us-east-1b"]

  group "show-count" {

    count = 2

    task "server" {

      driver = "docker"

      config {

        image = "hashicorp/http-echo:latest"

        args = [

          "-text", "'NOMAD_ALLOC_INDEX:${NOMAD_ALLOC_INDEX}",

          "-listen", ":${NOMAD_PORT_http}",

        ]

        port_map {

          http = "${NOMAD_PORT_http}"

        }

      }

      resources {

        network {

          mbits = 1

          port "http" {

            static = 80

          }

        }

      }

      service {

        name = "show-count"

        port = "http"

      }

    }

  }

}

[Greg Fausak]

Perfect! thx,

-g