From 3ad6fa80d45a31eb101f90c6b596efad6076502f Mon Sep 17 00:00:00 2001
From: Jan Weitz <jan@iosphere.de>
Date: Thu, 1 Jun 2017 13:47:16 +0200
Subject: [PATCH] Fix #798 - RBAC for leader election

Using gcr.io/google_containers/nginx-ingress-controller:0.9.0-beta.7
the nginx-controller needs to handle leader-election via configmaps.

To perform the leader-election the nginx-controller needs to have the
appropiate RBAC permissions.

Previously to this fix, the following errors occured:

-  cannot get configmaps in the namespace "NAMESPACE_PLACEHOLDER". (get configmaps ingress-controller-leader-nginx)
- initially creating leader election record: User "system:serviceaccount:NAMESPACE_PLACEHOLDER" cannot create configmaps in the namespace "NAMESPACE_PLACEHOLDER". (post configmaps)
---
 examples/rbac/nginx/README.md                     | 15 +++++++++++++++
 .../rbac/nginx/nginx-ingress-controller-rbac.yml  | 14 ++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/examples/rbac/nginx/README.md b/examples/rbac/nginx/README.md
index dd9042d59..3fee21b69 100644
--- a/examples/rbac/nginx/README.md
+++ b/examples/rbac/nginx/README.md
@@ -49,6 +49,21 @@ permissions are granted to the Role named `nginx-ingress-role`
 * `configmaps`, `pods`, `secrets`: get
 * `endpoints`: create, get, update
 
+Furthermore to support leader-election, the nginx-ingress-controller needs to
+have access to a `configmap` using the resourceName `ingress-controller-leader-nginx`
+
+* `configmaps`: create, get, update (for resourceName `ingress-controller-leader-nginx`)
+
+This resourceName is the concatenation of the `election-id` and the
+`ingress-class` as defined by the ingress-controller, which default to:
+
+* `election-id`: `ingress-controller-leader`
+* `ingress-class`: `nginx`
+* `resourceName` : `<election-id>-<ingress-class>`
+
+Please adapt accordingly if you overwrite either parameter when launching the
+nginx-ingress-controller.
+
 ### Bindings
 
 The ServiceAccount `nginx-ingress-serviceaccount` is bound to the Role
diff --git a/examples/rbac/nginx/nginx-ingress-controller-rbac.yml b/examples/rbac/nginx/nginx-ingress-controller-rbac.yml
index fbe50f7ae..87f97b58d 100644
--- a/examples/rbac/nginx/nginx-ingress-controller-rbac.yml
+++ b/examples/rbac/nginx/nginx-ingress-controller-rbac.yml
@@ -69,6 +69,20 @@ rules:
       - secrets
     verbs:
       - get
+  - apiGroups:
+      - ""
+    resources:
+      - configmaps
+    resourceNames:
+      # Defaults to "<election-id>-<ingress-class>"
+      # Here: "<ingress-controller-leader>-<nginx>"
+      # This has to be adapted if you change either parameter
+      # when launching the nginx-ingress-controller.
+      - "ingress-controller-leader-nginx"
+    verbs:
+      - create
+      - get
+      - update
   - apiGroups:
       - ""
     resources: