feat: Ability to specify existing secrets for values in Helm (#791)

Closes #790

charts/planka/templates/deployment.yaml

@@ -90,17 +90,37 @@ spec:
               value: http://localhost:3000
               {{- end }}
             - name: SECRET_KEY
+              {{- if .Values.existingSecretkeySecret }}
+              valueFrom:
+                secretKeyRef:
+                  name: {{ .Values.existingSecretkeySecret }}
+                  key: key
+              {{- else }}
               value: {{ required "A secret key needs to be generated using 'openssl rand -hex 64' and assigned to secretkey." .Values.secretkey }}
+              {{- end }}
             - name: TRUST_PROXY
               value: "0"
             - name: DEFAULT_ADMIN_EMAIL
               value: {{ .Values.admin_email }}
-            - name: DEFAULT_ADMIN_PASSWORD
-              value: {{ .Values.admin_password }}
             - name: DEFAULT_ADMIN_NAME
               value: {{ .Values.admin_name }}
+            {{- if .Values.existingAdminCredsSecret }}
+            - name: DEFAULT_ADMIN_USERNAME
+              valueFrom:
+                secretKeyRef:
+                  name: {{ .Values.existingAdminCredsSecret }}
+                  key: username
+            - name: DEFAULT_ADMIN_PASSWORD
+              valueFrom:
+                secretKeyRef:
+                  name: {{ .Values.existingAdminCredsSecret }}
+                  key: password
+            {{- else }}
             - name: DEFAULT_ADMIN_USERNAME
               value: {{ .Values.admin_username }}
+            - name: DEFAULT_ADMIN_PASSWORD
+              value: {{ .Values.admin_password }}
+            {{- end }}
           {{ range $k, $v := .Values.env }}
             - name: {{ $k | quote }}
               value: {{ $v | quote }}