I have already had a working Master - Slave Configuration on my Jenkins, but an update broke it so I had to reinstall it (didn't have a backup yet).
But now after reinstalling Jenkins I don't get it to work anymore.
When I go on Manage Jenkins -> Node Management I can only add new "permanent" Agents and not the old "Dumb Slave" Node I used to have. Was there an update or something so this doesn't work anymore?
Also when using this permanent Agent the help ? shows me the option "Launch agent via Java Web Start" on the Launch method field - but in the drop down it is not available.
Did I make something wrong on the installation?
edit: Using newest Version 2.16 of Jenkins
Ok, I found it myself!
In the Global Security, I didn't have a TCP port for JNLP agents enabled, which automatically disables the line "Launch agent via Java Web Start"
As mentioned here:
Manage Jenkins => Configure Global Security => Enable security => TCP port for JNLP agents Set it to either Fixed (for this option also set the port number) or Random.
Manage Jenkins => Configure Global Security => Enable security => TCP port for JNLP agents Set it to either Fixed (for this option also set the port number) or Random.
As of Jenkins version 2.176.3, there is option enabled when "Launch agent by connecting it to the master" which is same as "launch agent via java web start" once you enable the "Manage Jenkins => Configure Global Security => Agents => TCP port for inbound agents" as mentioned above. e.g. Fixed: 50000
来源：https://stackoverflow.com/questions/38724448/creating-a-jenkins-slave-via-java-web-start