Improve README

Author: Saverio Proto

README.md

@@ -23,24 +23,83 @@ preferences: {}
 users:
 - name: webhook
 ```
-- Copy the examples/policy.json and edit it to your needs.
+
+## Configuration on K8s master for authentication
+
 - Add the following flags to your Kubernetes api server.
   * `--authentication-token-webhook-config-file=/path/to/your/webhook.kubeconfig`
-  * `--authorization-mode=Webhook --authorization-webhook-config-file=/path/to/your/webhook.kubeconfig`
+  * `--authorization-mode=Node,RBAC`
 - Start webhook process with the following flags
   * `--tls-cert-file /var/run/kubernetes/serving-kube-apiserver.crt`
   * `--tls-private-key-file /var/run/kubernetes/serving-kube-apiserver.key`
   * `--keystone-policy-file examples/policy.json`
+  * `--keystone-url https://my.keystone:5000/v3`
+
+## Configuration on K8s master for authorization
+
+- Copy the examples/policy.json and edit it to your needs.
+- Add the following flags to your Kubernetes api server.
+  * `--authorization-mode=Webhook,Node --authorization-webhook-config-file=/path/to/your/webhook.kubeconfig`
+- When you start the webhook process make sure you also have the following flags (in addition to the flags in the case of authentication)
+  * `--keystone-policy-file examples/policy.json`
+
+## K8s kubectl Client configuration
+
+### Old kubectl clients
+
 - Run `openstack token issue` to generate a token
 - Run `kubectl --token $TOKEN get po` or `curl -k -v -XGET  -H "Accept: application/json" -H "Authorization: Bearer $TOKEN" https://localhost:6443/api/v1/namespaces/default/pods`
 
+### New kubectl clients v1.8.0 and later
+
+The client is able to read the `OS_` env variables used also by the openstackclient. You dont have to pass a token with `--token`, but the client will contact Keystone directly, will get a token and will use it. To configure the client to the following:
+
+- Run `kubectl config set-credentials openstackuser --auth-provider=openstack`
+
+This command creates the following entry in your ~/.kube/config
+```
+- name: openstackuser
+  user:
+    as-user-extra: {}
+    auth-provider:
+      name: openstack
+```
+- Run `kubectl config set-context --cluster=kubernetes --user=openstackuser openstackuser@kubernetes`
+- Run `kubectl config use-context openstackuser@kubernetes` to activate the context
+
+Source your env vars. Make sure you include `OS_DOMAIN_NAME` or the client will fallback to Keystone V2 that is not supported by the webhook.This env should be ok:
+
+```
+OS_AUTH_URL="https://keystone.example.com:5000/v3"
+OS_DOMAIN_NAME="default"
+OS_IDENTITY_API_VERSION="3"
+OS_PASSWORD="mysecret"
+OS_PROJECT_NAME="myproject"
+OS_REGION_NAME="myRegion"
+OS_USERNAME="username"
+```
+- Try: `kubectl get pods`
+
+In case you are using this Webhook just for the authentication, you should get an authorization error:
+```
+Error from server (Forbidden): pods is forbidden: User "username" cannot list pods in the namespace "default"
+```
+
+You need to configure the RBAC with roles to be authorized to do something, for example:
+
+``` kubectl create rolebinding username-view --clusterrole view --user username --namespace default```
+
+Try now again to see the pods with `kubectl get pods`
+
+## References
+
 More details about Kubernetes Authentication Webhook using Bearer Tokens is at :
 https://kubernetes.io/docs/admin/authentication/#webhook-token-authentication
 
 and the Authorization Webhook is at:
 https://kubernetes.io/docs/admin/authorization/webhook/
 
-Tips:
+## Tips
 
 - You can directly test the webhook with
 ```