100 days of devops - Day 75: Jenkins Slave Nodes nodes stays offline

[rwobben]

Anyone a hint why the nodes are still offline

I installed ssh agents and made the credits

[Srikanth_Reddy]

Have you checked if Java is installed on the node(stapp01)? It is a prerequisite for Jenkins to work.

[rwobben]

I have installed java 21 on stapp01 but still the node stays offline.

[Srikanth_Reddy]

I’ve tried adding node and it is working as expected. Change your launch method to Launch agents via SSH and pass the credentials.

[rwobben]

oke

But I do not have that choice even if I installed the ssh and ssh agents plugin

[Srikanth_Reddy]

If I remember it correctly you are supposed to install a plugin called SSH Build Agent. Check if that’s installed, if not install it. Also do restart Jenkins.

[rwobben]

I did those steps

But still not that choice to make

[Srikanth_Reddy]

Share screenshot of Installed Plugins tab and again did you restart Jenkins?

[rwobben]

oke

That part worked
But this looks not good

[rwobben]

oke

I see this error:

Caused by: java.io.IOException: PEM problem: it is of unknown type. 
Supported algorithms are :[ssh-ed25519, ecdsa-sha2-nistp521, 
ecdsa-sha2-nistp384, ecdsa-sha2-nistp256, rsa-sha2-256, rsa-sha2-512, 
ssh-rsa, ssh-dss]

Even if i do:

ssh-keygen -t rsa -b 2048 -m PEM

[Srikanth_Reddy]

I’m not sure what credentails you are using. You are supposed to use credentials present here. You don’t have to use ssh key-pairs.