[FIXED] Unable to connect local slave to Jenkins master on AWS

Issue

I've set-up a Jenkins on AWS ec2 instance. I have a few machines with me (Ubuntu, Mac) which are supposed to be the slaves.

I've configured the nodes on my Jenkins master and I'm trying to connect the slaves using JNLP-4 protocol via random ports.

I've enabled the Security, Selected the TCP Ports for agents as Random, Enable CLI over remoting, Enable Agent -> Master Access control.

After doing all these, when I try to connect I get the following error:

Vighneshs-MBP:Downloads vighneshpai$ java -jar agent.jar -jnlpUrl https://my.host.name/computer/Mac/slave-agent.jnlp -secret cf400d1a4e0a1dcc75da2b361efafbce3321e17b935bdcf14350a36e
Oct 11, 2018 8:43:50 PM hudson.remoting.jnlp.Main createEngine
INFO: Setting up agent: Mac
Oct 11, 2018 8:43:50 PM hudson.remoting.jnlp.Main$CuiListener <init>
INFO: Jenkins agent is running in headless mode.
Oct 11, 2018 8:43:50 PM hudson.remoting.Engine startEngine
INFO: Using Remoting version: 3.25
Oct 11, 2018 8:43:50 PM org.jenkinsci.remoting.engine.WorkDirManager initializeWorkDir
INFO: Using /Users/vighneshpai/Downloads/remoting as a remoting work directory
Both error and output logs will be printed to /Users/vighneshpai/Downloads/remoting
Oct 11, 2018 8:43:50 PM hudson.remoting.jnlp.Main$CuiListener status
INFO: Locating server among [https://my.host.name/]
Oct 11, 2018 8:43:51 PM org.jenkinsci.remoting.engine.JnlpAgentEndpointResolver resolve
INFO: Remoting server accepts the following protocols: [JNLP4-connect, JNLP-connect, Ping, JNLP2-connect, JNLP3-connect]
Oct 11, 2018 8:43:56 PM org.jenkinsci.remoting.engine.JnlpAgentEndpointResolver isPortVisible
WARNING: connect timed out
Oct 11, 2018 8:43:56 PM hudson.remoting.jnlp.Main$CuiListener error
SEVERE: https://my.host.name/ provided port:49187 is not reachable
java.io.IOException: https://my.host.name/ provided port:49187 is not reachable
    at org.jenkinsci.remoting.engine.JnlpAgentEndpointResolver.resolve(JnlpAgentEndpointResolver.java:286)
    at hudson.remoting.Engine.innerRun(Engine.java:523)
    at hudson.remoting.Engine.run(Engine.java:474)

I've also tried using a Fixed port and add the port to the allowed list of ports for Inbound access. Still not able to connect.

Same machines, without any problem connected to the Jenkins running on local machine.

What could be the problem?

Solution

Setting the property -Dhudson.TcpSlaveAgentListener.hostName in /etc/default/jenkins resolved my problem.

Answered By - Vighnesh Pai
Answer Checked By - Cary Denson (JavaFixing Admin)