Research Help improve navigation and content organization by answering a short survey. Start Survey
Nomad
Nomad Home

connect Block

Placementjob -> group -> service -> connect

The connect block allows configuring various options for Consul Connect. It is valid only within the context of a service definition at the task group level. For using connect when Consul ACLs are enabled, be sure to read through the Secure Nomad Jobs with Consul Connect guide.

job "countdash" {
  datacenters = ["dc1"]

  group "api" {
    network {
      mode = "bridge"
    }

    service {
      name = "count-api"
      port = "9001"

      connect {
        sidecar_service {}
      }
    }

    task "web" {
      driver = "docker"

      config {
        image = "hashicorpdev/counter-api:v3"
      }
    }
  }
}

connect Parameters

Used to configure a connect service. Only one of native, sidecar_service, or gateway may be realized per connect block.

  • native - (bool: false) - This is used to configure the service as supporting Connect Native applications.

  • sidecar_service - (sidecar_service: nil) - This is used to configure the sidecar service created by Nomad for Consul Connect.

  • sidecar_task - (sidecar_task:nil) - This modifies the task configuration of the Envoy proxy created as a sidecar or gateway.

  • gateway - (gateway:nil) - This is used to configure the gateway service created by Nomad for Consul Connect.

connect Examples

Using Connect Native

The following example is a minimal service block for a Consul Connect Native application implemented by a task named generate.

service {
  name = "uuid-api"
  port = "${NOMAD_PORT_api}"
  task = "generate"

  connect {
    native = true
  }
}

Using Sidecar Service

The following example is a minimal connect block with defaults and is sufficient to start an Envoy proxy sidecar for allowing incoming connections via Consul Connect.

  connect {
    sidecar_service {}
  }

The following example includes specifying upstreams.

  connect {
     sidecar_service {
       proxy {
         upstreams {
           destination_name = "count-api"
           local_bind_port = 8080
         }
       }
     }
  }

The following is the complete countdash example. It includes an API service and a frontend Dashboard service which connects to the API service as a Connect upstream. Once running, the dashboard is accessible at localhost:9002.

job "countdash" {
  datacenters = ["dc1"]

  group "api" {
    network {
      mode = "bridge"
    }

    service {
      name = "count-api"
      port = "9001"

      connect {
        sidecar_service {}
      }

      check {
        expose   = true
        type     = "http"
        name     = "api-health"
        path     = "/health"
        interval = "10s"
        timeout  = "3s"
      }
    }

    task "web" {
      driver = "docker"

      config {
        image = "hashicorpdev/counter-api:v3"
      }
    }
  }

  group "dashboard" {
    network {
      mode = "bridge"

      port "http" {
        static = 9002
        to     = 9002
      }
    }

    service {
      name = "count-dashboard"
      port = "9002"

      connect {
        sidecar_service {
          proxy {
            upstreams {
              destination_name = "count-api"
              local_bind_port  = 8080
            }
          }
        }
      }
    }

    task "dashboard" {
      driver = "docker"

      env {
        COUNTING_SERVICE_URL = "http://${NOMAD_UPSTREAM_ADDR_count_api}"
      }

      config {
        image = "hashicorpdev/counter-dashboard:v3"
      }
    }
  }
}

Using a Gateway

The following is an example service block for creating and using a connect ingress gateway. It includes a gateway service definition and an api service fronted by the gateway. Once running, the gateway can be used to reach the api service by first looking up the gateway Consul DNS address, e.g.

curl $(dig +short @127.0.0.1 -p 8600 uuid-api.ingress.dc1.consul. ANY):8080

job "ingress-demo" {

  datacenters = ["dc1"]

  group "ingress-group" {

    network {
      mode = "bridge"
      port "inbound" {
        static = 8080
        to     = 8080
      }
    }

    service {
      name = "my-ingress-service"
      port = "8080"

      connect {
        gateway {
          ingress {
            listener {
              port     = 8080
              protocol = "tcp"
              service {
                name = "uuid-api"
              }
            }
          }
        }
      }
    }
  }
}

Limitations

Edit this page on GitHub