feat: add support for extra volumes

Add support for extra volumes. This can be useful for mounting files
from k8s secrets and referencing them from the flipt config (e.g. Git
SSH key files).

charts/flipt/templates/deployment.yaml

@@ -55,6 +55,9 @@ spec:
             {{- if .Values.persistence.subPath }}
               subPath: {{ .Values.persistence.subPath }}
             {{- end }}
+            {{ if .Values.extraVolumeMounts }}
+            {{- toYaml .Values.extraVolumeMounts | nindent 12 }}
+            {{- end }}
           livenessProbe:
             httpGet:
               path: /health
@@ -80,6 +83,9 @@ spec:
         {{- else }}
           emptyDir: {}
         {{- end }}
+        {{- if .Values.extraVolumes }}
+        {{- toYaml .Values.extraVolumes | nindent 8 }}
+        {{- end }}
       {{- with .Values.nodeSelector }}
       nodeSelector:
         {{- toYaml . | nindent 8 }}

charts/flipt/values.yaml

@@ -189,3 +189,15 @@ metrics:
     scheme: http
     # -- ServiceMonitor will use these tlsConfig settings to make the health check requests
     tlsConfig: null
+
+# extraVolumeMounts is a list of extra volumes to mount to the flipt container
+# - name: flipt-git-ssh-key
+#   mountPath: /etc/flipt/ssh.key
+#   subPath: ssh.key
+extraVolumeMounts: []
+
+# extraVolumes is a list of extra volumes to mount to the pod
+# - name: flipt-git-ssh-key
+#   secret:
+#     secretName: flit-git-ssh-key-secret
+extraVolumes: []