Jenkins java.net.UnknownHostException Error

Question

So when running a Jenkins job i'm getting the following error:

Unable to get host name
java.net.UnknownHostException: ip-XX-XX-XX-XXX: ip-XX-XX-XX-XXX: Name or service not known

I've read online about editing the /etc/hosts file. Right now mine looks like

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost6 localhost6.localdomain6

I've done a lot of trail and error and have yet to find a solution that works.

Answer 1

At a guess your environment is trying to get the IP of the local machine from the hostname. AWS names hosts something like ip-172-30-1-34 by default but that value isn't in /etc/hosts.

A very quick fix would be to add the output from hostname on the command line to /etc/hosts. As root, something like

echo "127.0.0.1 hostname" >> /etc/hosts

NOTE - the hostname above needs to be surrounded by backquotes but that character is also used by Stackoverflow - don't forget it.