Add instructions for Jenkins node on EL9

docs/jenkins.md

@@ -44,7 +44,7 @@ https://github.com/theforeman/foreman-infra/tree/master/puppet/modules contains
 
 ### Node requirements
 
-* CentOS 7
+* CentOS Stream
   * Clean, minimal base installation or the option to reinstall it
 * 2GB of RAM per vCPU (4 vCPU + 8GB RAM is typical)
 * 60GB disk (minimum), SSD preferred
@@ -54,6 +54,20 @@ https://github.com/theforeman/foreman-infra/tree/master/puppet/modules contains
 
 ### Configuring a new node
 
+For Enterprise Linux 9:
+
+* Ensure yum.puppet.com is configured: [puppet7-release](https://yum.puppet.com/puppet7-release-el-9.noarch.rpm)
+* `yum -y install puppet-agent`
+* `echo "server = puppet.theforeman.org" >> /etc/puppetlabs/puppet/puppet.conf`
+* ensure hostname is set node0X.jenkins.<provider\>.theforeman.org where <provider\> is osuosl or aws for example and that the record is in DNS
+* Make the `puppet` command available: `source /etc/profile.d/puppet-agent.sh`
+* `puppet ssl bootstrap`
+* Sign the certificate on the puppetmaster or via Foreman
+* `puppet agent --test`
+* Set the host group to "Builders" in Foreman
+* Run `puppet agent --test` twice (second run is important, due to the rvm module behaviour)
+
+
 For Enterprise Linux 8:
 
 * Ensure yum.puppet.com is configured: [puppet7-release](https://yum.puppet.com/puppet7-release-el-8.noarch.rpm)