Nomad Job Samples

Placing job task on certain node

 constraint {
        attribute = "${node.unique.name}"
        operator = "regexp"
        value = "agent.*"  # Regex selector
}

constraint {
  operator  = "distinct_hosts"
  value     = "true"
}

constraint {
  operator  = "distinct_property"
  attribute = "${meta.rack}"
  value     = "3"
}

Think to note here is that after applying the job the tasks may not be shut-down on previous selector because target node may not exists and to prevent the outage it will stay the same. It depends on configuration.

Running JAR from URL

// TODO

Running Docker Image

job "running-nexus-in-docker" {
  type        = "service"
  datacenters = ["dc1"]

    task "jar" {
      driver = "docker"
      config {
        image = "sonatype/nexus3"
        labels {
          group = "nexus"
        }
      }
    }
}

Limiting Task Resource Usage

job "running-nexus-in-docker" {
  type        = "service"
  datacenters = ["dc1"]

  task "jar" {
    driver = "docker"
    config {
      image = "sonatype/nexus3"
      labels {
        group = "nexus"
      }
    }
    resources {
      memory = 1024
      cores = 2
    }
  }
}

Using Consul keys/values and reacting to changes

job "fetch-consul-key" {
  datacenters = ["dc1"]

  group "cache" {

    task "consul-echo-key" {
      driver = "docker"

      template {
        destination = "/local/config"
        data = <<EOF
CONSUL_KEY={{ key "consul-key" }}
EOF
        env = true
      }

      config {
        image        = "redis:3.2"
        network_mode = "host"
        command      = "sh"
        args         = ["-c", "echo $CONSUL_KEY; sleep 10000"]
      }

      resources {
        cpu    = 500 # 500 MHz
        memory = 256 # 256MB
      }
    }
  }
}

Usually all files are placed in /local/* directory.