Add handling of empty WATCH_NAMESPACE value of jenkins.namespace (#609)

* Add note that jenkins.namespace also affects jenkins-operator resources

* Add handling of empty WATCH_NAMESPACE value of jenkins.namespace

If jenkins.namespace is set to "", it leads to WATCH_NAMESPACE
environment value of Jenkins Operator itself to be set to "", which
leads that operator watches all namespaces (see
https://github.com/jenkinsci/kubernetes-operator/issues/77#issuecomment-523727092).
This case requires custom handling: instead of creating role and
role_binding we need to create clusterrole and clusterrolebinding with
the required permissions.

* Bump chart version

* Fix grammar as suggested by @Sig00rd

Co-authored-by: Sig00rd <sz.fugas@gmail.com>

chart/jenkins-operator/templates/_role.yaml

@@ -1,11 +1,13 @@
 {{ define "jenkins-operator.role" }}
 {{ $namespace := . }}
 ---
-kind: Role
+kind: {{ if eq $namespace "" }}ClusterRole{{ else }}Role{{ end }}
 apiVersion: rbac.authorization.k8s.io/v1
 metadata:
   name: jenkins-operator
+{{- if ne $namespace "" }}
   namespace: {{ $namespace }}
+{{- end }}
 rules:
   - apiGroups:
       - apps

chart/jenkins-operator/templates/role_binding.yaml

@@ -12,7 +12,28 @@ roleRef:
   kind: Role
   name: jenkins-operator
   apiGroup: rbac.authorization.k8s.io
-{{ if ne .Release.Namespace .Values.jenkins.namespace }}
+{{ if eq .Values.jenkins.namespace "" }}
+{{- /*
+# This is a special case when .Values.jenkins.namespace is equal to empty
+# string which leads to WATCH_NAMESPACE env of jenkins-operator to be set to
+# empty string and leads to operator actually watching all namespaces. In this
+# case we need to create clusterrole and clusterrolebinding instead of role and
+# rolebinding
+*/}}
+---
+kind: ClusterRoleBinding
+apiVersion: rbac.authorization.k8s.io/v1
+metadata:
+  name: jenkins-operator
+subjects:
+  - kind: ServiceAccount
+    name: jenkins-operator
+    namespace: {{ .Release.Namespace }}
+roleRef:
+  kind: ClusterRole
+  name: jenkins-operator
+  apiGroup: rbac.authorization.k8s.io
+{{ else if ne .Release.Namespace .Values.jenkins.namespace }}
 ---
 kind: RoleBinding
 apiVersion: rbac.authorization.k8s.io/v1

chart/jenkins-operator/values.yaml

@@ -18,6 +18,7 @@ jenkins:
   # namespace is the namespace where the resources will be deployed
   # It's not recommended to use default namespace
   # Create new namespace for jenkins (called e.g. jenkins)
+  # Note: this affects roles and rolebindings for jenkins operator itself
   namespace: default
 
   # labels are injected into metadata labels field