Is there additional setup for connecting Nomad and Jenkins?

Question

I'm interested in setting up Jenkins to test and launch my applications on Nomad and am trying to connect the two using https://github.com/jenkinsci/nomad-plugin

I've installed and been able to connect to and validate the connection to Nomad from Jenkins. I have a simple pipeline that just echos via bash, and I can see Jenkins is able to launch Nomad jobs and allocations. However, these jobs stall and die. Looking at the Nomad logs, I can see:

INFO: Locating server among [http://localhost:8080/]
May 06, 2022 8:16:36 PM hudson.remoting.jnlp.Main$CuiListener error
SEVERE: Failed to connect to http://localhost:8080/tcpSlaveAgentListener/: Connection refused (Connection refused)

It sounds like Nomad isn't able to find its way back to Jenkins, even though that's the correct Jenkins port on my machine.

Is there some additional setup I need to follow to allow Nomad to pass information back to Jenkins? Is there an issue with the tunnel? I did enable the fixed tunnel port of 50000 to match the template below.

My Nomad job template in Jenkins:

{
  "Job": {
    "Region": "global",
    "ID": "%WORKER_NAME%",
    "Type": "batch",
    "Datacenters": [
      "dc1"
    ],
    "TaskGroups": [
      {
        "Name": "jenkins-worker-taskgroup",
        "Count": 1,
        "RestartPolicy": {
          "Attempts": 0,
          "Interval": 10000000000,
          "Mode": "fail",
          "Delay": 1000000000
        },
        "Tasks": [
          {
            "Name": "jenkins-worker",
            "Driver": "docker",
            "Config": {
              "image": "jenkins/inbound-agent"
            },
            "Env": {
              "JENKINS_URL": "http://localhost:8080",
              "JENKINS_AGENT_NAME": "%WORKER_NAME%",
              "JENKINS_SECRET": "%WORKER_SECRET%",
              "JENKINS_TUNNEL": "http://localhost:50000"
            },
            "Resources": {
              "CPU": 500,
              "MemoryMB": 256
            }
          }
        ],
        "EphemeralDisk": {
          "SizeMB": 300
        }
      }
    ]
  }
}

Answer 1

"JENKINS_URL": "http://localhost:8080",

The address of jenkins url is invalid, which is what the message is about. Give the ip address of jenkins instance, not localhost. localhost inside the docker container is the docker container localhost.

Also, remember to enable connections to port 50000 in jenkins, there is an option for that.