Deploy and relate of jenkins/jenkins-slave from charmstore with default config, slaves unable to start and connect

[moon127]

Deploy cs:jenkins (36) and cs:jenkins-slave (13) eg current in charm store.

juju add-relation jenkins jenkins-slave - both machines in the same model under local lxd provider.

juju status looks clear:

App Version Status Scale Charm Store Rev OS Notes
jenkins active 1 jenkins jujucharms 36 ubuntu
jenkins-slave active 1 jenkins-slave jujucharms 13 ubuntu

Unit Workload Agent Machine Public address Ports Message
jenkins-slave/0* active idle 1 10.42.84.102 ready - using jenkins from relation
jenkins/0* active idle 0 10.42.84.105 8080/tcp,48484/tcp Jenkins is running

Machine State DNS Inst id Series AZ Message
0 started 10.42.84.105 juju-34409c-0 focal Running
1 started 10.42.84.102 juju-34409c-1 bionic Running

However acces the admin UI and the slave appears to not connect:

JNLP agent port is disabled and agents cannot connect this way. Go to security configuration screen and change it.

Note we are not configuring the jnlp port explicitly but the docs at https://jaas.ai/jenkins use the following as a deployment example:

Usage

If you want to run jobs on separate nodes you will also need to deploy the jenkins-slave charm:

juju deploy jenkins
juju deploy -n 5 jenkins-slave
juju add-relation jenkins jenkins-slave

Slaves will attempt to connect via JNLP on port 48484 by default. This is configurable, e.g.:

juju config jenkins jnlp-port=12345

If you want the previously-default behaviour of a random TCP port, you can set this to -1:

juju config jenkins jnlp-port=-1

Or if you want to disable the feature entirely, set it to 0:

juju config jenkins jnlp-port=0

The above implies default port 48484 per the juju status should be open - and per the jaas.ai notes we haven't explcitly called expose: true - but this is local lxd with no secgroups etc.