Windows Jenkins Slave unable to connect to master hosted on Openshift instance

Question

Unable to connect jenkins master hosted On Openshift Cluster. Terminates with below error after handshaking:

may 23, 2020 2:05:55 PM hudson.remoting.jnlp.Main$CuiListener error
GRAVE: Failed to connect to jenkins-jnlp-poc:50000
java.io.IOException: Failed to connect to jenkins-jnlp-poc:50000
        at org.jenkinsci.remoting.engine.JnlpAgentEndpoint.open(JnlpAgentEndpoint.java:246)
        at hudson.remoting.Engine.connectTcp(Engine.java:678)
        at hudson.remoting.Engine.innerRun(Engine.java:556)
        at hudson.remoting.Engine.run(Engine.java:488)
Caused by: java.net.ConnectException: Connection timed out: connect
        at sun.nio.ch.Net.connect0(Native Method)
        at sun.nio.ch.Net.connect(Net.java:454)
        at sun.nio.ch.Net.connect(Net.java:446)
        at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:648)
        at java.nio.channels.SocketChannel.open(SocketChannel.java:189)
        at org.jenkinsci.remoting.engine.JnlpAgentEndpoint.open(JnlpAgentEndpoint.java:204)
        ... 3 more

I added route to jenkins-jnlp service but I'm not able to expose the port, I'been trying to configure nodePort but I couldn't archive it yet. Any help will be welcomed! Thanks.

Answer 1

A Route will only work with HTTP / HTTPS traffic and will not work in this case and as you correctly noted, NodePorts is most likely what you want. Here is an example for a Service type NodePort using Port 32000:

apiVersion: v1
kind: Service
metadata:  
  name: jenkins-jnlp-poc-service
spec:
  selector:    
    app: jenkins-jnlp-poc
  type: NodePort
  ports:  
  - name: jnlp
    port: 50000
    targetPort: 50000
    nodePort: 32000
    protocol: TCP

Note that you may need to change multiple parts of the Service:

• The port and targetPort specifying which port the Service "listens" on and where traffic is forwarded to (typically to the port your container exposes)

• The selector, which Pods are targeted (you'll need to check your Pods which labels are used and adjust accordingly)