Add initContainer to clean up Gerrit site

Since parts of the Gerrit site are persisted through pod restarts, some
remnants could keep Gerrit from restarting, e.g. the ./logs/gerrit.pid
file.

This change adds an initContainer dedicated to clean up the site before
Gerrit starts up. At this point in time, it only removes the gerrit.pid
file, if present.

Change-Id: Ie10f309abf8b4a77fdbdd836d4380187ce1b849f

helm-charts/gerrit-master/templates/gerrit-master.deployment.yaml

diff --git a/helm-charts/gerrit-master/templates/gerrit-master.deployment.yaml b/helm-charts/gerrit-master/templates/gerrit-master.deployment.yaml
index 95b57c7..19dbdab 100644
--- a/helm-charts/gerrit-master/templates/gerrit-master.deployment.yaml
+++ b/helm-charts/gerrit-master/templates/gerrit-master.deployment.yaml
@@ -24,6 +24,20 @@
       - name: {{ .Values.images.registry.ImagePullSecret.name }}
       {{- end }}
       initContainers:
+      - name: site-cleanup
+        image: busybox
+        securityContext:
+          runAsUser: 1000
+          runAsGroup: 100
+        command:
+        - sh
+        - -c
+        args:
+        - |
+          rm -f /var/gerrit/logs/gerrit.pid
+        volumeMounts:
+        - name: gerrit-logs
+          mountPath: "/var/gerrit/logs"
       - name: gerrit-init
         image: {{ template "registry" . }}{{ .Values.gerritMaster.images.gerritInit }}:{{ .Values.images.version }}
         imagePullPolicy: {{ .Values.images.imagePullPolicy }}

helm-charts/gerrit-slave/templates/gerrit-slave.deployment.yaml

diff --git a/helm-charts/gerrit-slave/templates/gerrit-slave.deployment.yaml b/helm-charts/gerrit-slave/templates/gerrit-slave.deployment.yaml
index 8faf76c..c54955d 100644
--- a/helm-charts/gerrit-slave/templates/gerrit-slave.deployment.yaml
+++ b/helm-charts/gerrit-slave/templates/gerrit-slave.deployment.yaml
@@ -24,6 +24,20 @@
       - name: {{ .Values.images.registry.ImagePullSecret.name }}
       {{- end }}
       initContainers:
+      - name: site-cleanup
+        image: busybox
+        securityContext:
+          runAsUser: 1000
+          runAsGroup: 100
+        command:
+        - sh
+        - -c
+        args:
+        - |
+          rm -f /var/gerrit/logs/gerrit.pid
+        volumeMounts:
+        - name: gerrit-logs
+          mountPath: "/var/gerrit/logs"
       {{ if not .Values.gerritSlave.initializeTestSite.enabled -}}
       # Initialize the emptyDir containing the whole Gerrit-site with defaults
       # Not needed, when running in test mode, since then the configured site will
@@ -118,8 +132,6 @@
         - -c
         args:
         - |
-          rm -f /var/gerrit/logs/gerrit.pid
-
           {{ if .Values.gerritSlave.keystore -}}
           ln -s /var/keystore /var/gerrit/etc/keystore
           {{- end }}