Allow replacement of Jenkins config with configMap. (#7450)

Currently, the configMap is only used to write the initial
config.xml, etc to /var/jenkins_home.  Any changes to the
config are not used by Jenkins, because the `cp` operation
uses `--no-clobber`.

This adds a new `.Values.Master.OverwriteConfig` option to
allow a user to specify that the configMap should always
overwrite the config.xml, jenkins.CLI.xml, and
jenkins.model.JenkinsLocationConfiguration.xml
files.

By default, the `.Values.Master.OverwriteConfig` option is `false`
to preserve the current behavior.

Fixes #3133.

Signed-off-by: Logan Owen <logan@s1network.com>

stable/jenkins/Chart.yaml

@@ -1,6 +1,6 @@
 name: jenkins
 home: https://jenkins.io/
-version: 0.17.0
+version: 0.18.0
 appVersion: 2.121.3
 description: Open source continuous integration server. It supports multiple SCM tools
   including CVS, Subversion and Git. It can execute Apache Ant and Apache Maven-based

stable/jenkins/README.md

@@ -63,6 +63,7 @@ The following tables list the configurable parameters of the Jenkins chart and t
 | `Master.LoadBalancerIP`           | Optional fixed external IP           | Not set                                                                      |
 | `Master.JMXPort`                  | Open a port, for JMX stats           | Not set                                                                      |
 | `Master.CustomConfigMap`          | Use a custom ConfigMap               | `false`                                                                      |
+| `Master.OverwriteConfig`          | Replace config w/ ConfigMap on boot  | `false`                                                                      |
 | `Master.Ingress.Annotations`      | Ingress annotations                  | `{}`                                                                         |
 | `Master.Ingress.TLS`              | Ingress TLS configuration            | `[]`                                                                         |
 | `Master.InitScripts`              | List of Jenkins init scripts         | Not set                                                                      |

stable/jenkins/templates/config.yaml

@@ -192,9 +192,15 @@ data:
   apply_config.sh: |-
     mkdir -p /usr/share/jenkins/ref/secrets/;
     echo "false" > /usr/share/jenkins/ref/secrets/slave-to-master-security-kill-switch;
-    cp -n /var/jenkins_config/config.xml /var/jenkins_home;
-    cp -n /var/jenkins_config/jenkins.CLI.xml /var/jenkins_home;
-    cp -n /var/jenkins_config/jenkins.model.JenkinsLocationConfiguration.xml /var/jenkins_home;
+{{- if .Values.Master.OverwriteConfig }}
+    cp /var/jenkins_config/config.xml /var/jenkins_home;
+    cp /var/jenkins_config/jenkins.CLI.xml /var/jenkins_home;
+    cp /var/jenkins_config/jenkins.model.JenkinsLocationConfiguration.xml /var/jenkins_home;
+{{- else }}
+    cp --no-clobber /var/jenkins_config/config.xml /var/jenkins_home;
+    cp --no-clobber /var/jenkins_config/jenkins.CLI.xml /var/jenkins_home;
+    cp --no-clobber /var/jenkins_config/jenkins.model.JenkinsLocationConfiguration.xml /var/jenkins_home;
+{{- end }}
 {{- if .Values.Master.InstallPlugins }}
     # Install missing plugins
     cp /var/jenkins_config/plugins.txt /var/jenkins_home;

stable/jenkins/values.yaml

@@ -109,6 +109,10 @@ Master:
   #   test: |-
   #     <<xml here>>
   CustomConfigMap: false
+  # By default, the configMap is only used to set the initial config the first time
+  # that the chart is installed.  Setting `OverwriteConfig` to `true` will overwrite
+  # the jenkins config with the contents of the configMap every time the pod starts.
+  OverwriteConfig: false
   # Node labels and tolerations for pod assignment
   # ref: https://kubernetes.io/docs/concepts/configuration/assign-pod-node/#nodeselector
   # ref: https://kubernetes.io/docs/concepts/configuration/assign-pod-node/#taints-and-tolerations-beta-feature