Basic RBAC functionality. (Based from work done by @jwfang (#1351))

* Add a flag "authorization_method", when set to "RBAC" enables role based access control.
* Add required cluster roles and bindings for kube-dns
* Patch tiller deployment to use a service account with proper credentials.
* Add a flag to regenerate kubernetes certs on the nodes.

docs/vars.md

@@ -67,6 +67,10 @@ following default cluster paramters:
   OpenStack (default is unset)
 * *kube_hostpath_dynamic_provisioner* - Required for use of PetSets type in
   Kubernetes
+* *authorization_mode* - Set this to "RBAC" (upper-case, no quotes) 
+[to enable Role Based Access Control](https://kubernetes.io/docs/admin/authorization/rbac/)
+* *rotate_kubernetes_certs* - Set this to true to regenerate kubernetes Node certificates. *Warning: Will overwrite old certs.*
+ 
  
 Note, if cloud providers have any use of the ``10.233.0.0/16``, like instances'
 private addresses, make sure to pick another values for ``kube_service_addresses``
@@ -116,3 +120,4 @@ The possible vars are:
 
 Kargo sets up two Kubernetes accounts by default: ``root`` and ``kube``. Their
 passwords default to changeme. You can set this by changing ``kube_api_pwd``.
+

roles/kubernetes-apps/ansible/defaults/main.yml

@@ -40,3 +40,11 @@ netchecker_server_memory_requests: 64M
 # SSL
 etcd_cert_dir: "/etc/ssl/etcd/ssl"
 canal_cert_dir: "/etc/canal/certs"
+
+# RBAC
+rbac_resources:
+  - clusterrole,
+  - clusterrolebinding,
+  - sa
+
+rbac_enabled: "{{ authorization_mode == 'RBAC' }}"

roles/kubernetes-apps/ansible/tasks/main.yml

@@ -13,12 +13,15 @@
     src: "{{item.file}}"
     dest: "{{kube_config_dir}}/{{item.file}}"
   with_items:
-    - {name: kube-dns, file: kubedns-serviceaccount.yml, type: serviceaccount}
+    - {name: kubedns, file: kubedns-sa.yml, type: sa}
     - {name: kubedns, file: kubedns-deploy.yml, type: deployment}
     - {name: kubedns, file: kubedns-svc.yml, type: svc}
+    - {name: kubedns-autoscaler, file: kubedns-autoscaler-sa.yml, type: sa}
+    - {name: kubedns-autoscaler, file: kubedns-autoscaler-clusterrole.yml, type: clusterrole}
+    - {name: kubedns-autoscaler, file: kubedns-autoscaler-clusterrolebinding.yml, type: clusterrolebinding}
     - {name: kubedns-autoscaler, file: kubedns-autoscaler.yml, type: deployment}
   register: manifests
-  when: dns_mode != 'none' and inventory_hostname == groups['kube-master'][0]
+  when: dns_mode != 'none' and inventory_hostname == groups['kube-master'][0] and (item.type not in rbac_resources or rbac_enabled)
   tags: dnsmasq
 
 - name: Kubernetes Apps | Start Resources
@@ -30,6 +33,7 @@
     filename: "{{kube_config_dir}}/{{item.item.file}}"
     state: "{{item.changed | ternary('latest','present') }}"
   with_items: "{{ manifests.results }}"
+  failed_when: manifests|failed and "Error from server (AlreadyExists)" not in manifests.msg
   when: dns_mode != 'none' and inventory_hostname == groups['kube-master'][0]
   tags: dnsmasq
 
@@ -37,3 +41,4 @@
   include: tasks/netchecker.yml
   when: deploy_netchecker
   tags: netchecker
+

roles/kubernetes-apps/ansible/templates/kubedns-autoscaler-clusterrole.yml

@@ -0,0 +1,32 @@
+# Copyright 2016 The Kubernetes Authors. All rights reserved
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+kind: ClusterRole
+apiVersion: rbac.authorization.k8s.io/v1beta1
+metadata:
+  name: cluster-proportional-autoscaler
+  namespace: kube-system
+rules:
+  - apiGroups: [""]
+    resources: ["nodes"]
+    verbs: ["list"]
+  - apiGroups: [""]
+    resources: ["replicationcontrollers/scale"]
+    verbs: ["get", "update"]
+  - apiGroups: ["extensions"]
+    resources: ["deployments/scale", "replicasets/scale"]
+    verbs: ["get", "update"]
+  - apiGroups: [""]
+    resources: ["configmaps"]
+    verbs: ["get", "create"]

roles/kubernetes-apps/ansible/templates/kubedns-autoscaler-clusterrolebinding.yml

@@ -0,0 +1,27 @@
+# Copyright 2016 The Kubernetes Authors. All rights reserved
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+kind: ClusterRoleBinding
+apiVersion: rbac.authorization.k8s.io/v1beta1
+metadata:
+  name: cluster-proportional-autoscaler
+  namespace: kube-system
+subjects:
+  - kind: ServiceAccount
+    name: cluster-proportional-autoscaler
+    namespace: kube-system
+roleRef:
+  kind: ClusterRole
+  name: cluster-proportional-autoscaler
+  apiGroup: rbac.authorization.k8s.io

roles/kubernetes-apps/ansible/templates/kubedns-autoscaler-sa.yml

@@ -0,0 +1,19 @@
+# Copyright 2016 The Kubernetes Authors. All rights reserved
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+kind: ServiceAccount
+apiVersion: v1
+metadata:
+  name: cluster-proportional-autoscaler
+  namespace: kube-system

roles/kubernetes-apps/ansible/templates/kubedns-autoscaler.yml

@@ -46,4 +46,5 @@ spec:
           - --default-params={"linear":{"nodesPerReplica":{{ kubedns_nodes_per_replica }},"min":{{ kubedns_min_replicas }}}}
           - --logtostderr=true
           - --v=2
-
+      serviceAccountName: cluster-proportional-autoscaler
+      serviceAccount: cluster-proportional-autoscaler

roles/kubernetes-apps/ansible/templates/kubedns-deploy.yml

@@ -114,4 +114,6 @@ spec:
         - containerPort: 8080
           protocol: TCP
       dnsPolicy: Default  # Don't use cluster DNS.
-      serviceAccountName: kube-dns
+{% if authorization_mode is defined and authorization_mode == "RBAC" %}
+      serviceAccount: kube-dns
+{% endif %}

roles/kubernetes-apps/helm/defaults/main.yml

@@ -2,3 +2,5 @@ helm_enabled: false
 
 # specify a dir and attach it to helm for HELM_HOME.
 helm_home_dir: "/root/.helm"
+
+rbac_enabled: "{{ authorization_mode == 'RBAC' }}"

roles/kubernetes-apps/helm/tasks/main.yml

@@ -10,10 +10,28 @@
     mode: 0755
   register: helm_container
 
+- name: Helm | Configure tiller service account for RBAC
+  command: kubectl create serviceaccount tiller --namespace=kube-system
+  ignore_errors: yes
+  when: rbac_enabled
+
+- name: Helm | Configure tiller rolebindings for RBAC
+  command: kubectl create clusterrolebinding tiller --clusterrole=cluster-admin --serviceaccount=kube-system:tiller
+  ignore_errors: yes
+  when: rbac_enabled
+
 - name: Helm | Install/upgrade helm
   command: "{{ bin_dir }}/helm init --upgrade --tiller-image={{ tiller_image_repo }}:{{ tiller_image_tag }}"
   when: helm_container.changed
 
+- name: Helm | Patch tiller deployment for RBAC
+  shell: >
+    kubectl --namespace=kube-system get deployment tiller-deploy -o json | \
+    python -c 'import sys,json;a=json.load(sys.stdin);a["spec"]["template"]["spec"]["serviceAccount"]="tiller";json.dump(a,sys.stdout)' | \
+    kubectl apply -f -
+  when: rbac_enabled
+
 - name: Helm | Set up bash completion
   shell: "umask 022 && {{ bin_dir }}/helm completion bash >/etc/bash_completion.d/helm.sh"
   when: ( helm_container.changed and not ansible_os_family in ["CoreOS", "Container Linux by CoreOS"] )
+

roles/kubernetes/master/defaults/main.yml

@@ -65,3 +65,5 @@ apiserver_custom_flags: []
 controller_mgr_custom_flags: []
 
 scheduler_custom_flags: []
+
+authorization_mode: RBAC

roles/kubernetes/master/templates/manifests/kube-apiserver.manifest.j2

@@ -81,6 +81,9 @@ spec:
 {% if kube_api_anonymous_auth is defined and kube_version | version_compare('v1.5', '>=')  %}
     - --anonymous-auth={{ kube_api_anonymous_auth }}
 {% endif %}
+{% if authorization_mode %}
+    - --authorization-mode={{ authorization_mode }}
+{% endif %}
 {% if apiserver_custom_flags is string %}
     - {{ apiserver_custom_flags }}
 {% else %}

roles/kubernetes/master/templates/manifests/kube-controller-manager.manifest.j2

@@ -35,6 +35,9 @@ spec:
     - --node-monitor-period={{ kube_controller_node_monitor_period }}
     - --pod-eviction-timeout={{ kube_controller_pod_eviction_timeout }}
     - --v={{ kube_log_level }}
+{% if authorization_mode is defined and authorization_mode == "RBAC" %}
+    - --use-service-account-credentials
+{% endif %}
 {% if cloud_provider is defined and cloud_provider in ["openstack", "azure", "vsphere"] %}
     - --cloud-provider={{cloud_provider}}
     - --cloud-config={{ kube_config_dir }}/cloud_config

roles/kubernetes/node/handlers/main.yml

@@ -1,4 +1,9 @@
 ---
+- name: restart kubelet if secrets changed
+  command: /bin/true
+  when: secret_changed|d(False)
+  notify: restart kubelet
+
 - name: restart kubelet
   command: /bin/true
   notify:

roles/kubernetes/node/tasks/pre_upgrade.yml

@@ -4,3 +4,7 @@
   args:
     creates: "/var/lib/cni"
   failed_when: false
+
+- name: "Pre-upgrade | Make sure to restart kubelet if certificates changed"
+  command: /bin/true
+  notify: restart kubelet if secrets changed

roles/kubernetes/node/templates/manifests/kube-proxy.manifest.j2

@@ -44,6 +44,9 @@ spec:
     - mountPath: "{{ kube_config_dir }}/ssl"
       name: etc-kube-ssl
       readOnly: true
+    - mountPath: {{kube_config_dir}}/kube-proxy-kubeconfig.yaml
+      name: "kubeconfig"
+      readOnly: true
     - mountPath: "{{ kube_config_dir }}/kube-proxy-kubeconfig.yaml"
       name: kubeconfig
       readOnly: true
@@ -63,7 +66,10 @@ spec:
       path: "{{ kube_config_dir }}/ssl"
   - name: kubeconfig
     hostPath:
-      path: "{{ kube_config_dir }}/kube-proxy-kubeconfig.yaml"
+      path: "{{kube_config_dir}}/kube-proxy-kubeconfig.yaml"
+  - name: "etc-kube-ssl"
+    hostPath:
+      path: "{{kube_config_dir}}/ssl"
   - name: var-run-dbus
     hostPath:
       path: /var/run/dbus

roles/kubernetes/secrets/defaults/main.yml

@@ -1,2 +1,4 @@
 ---
 kube_cert_group: kube-cert
+
+rotate_kubernetes_certs: false # set this to true to regenerate certificates

roles/kubernetes/secrets/tasks/check-certs.yml

@@ -10,8 +10,8 @@
 
 - name: "Check_certs | Set default value for 'sync_certs', 'gen_certs', and 'secret_changed'  to false"
   set_fact:
-    sync_certs: false
-    gen_certs: false
+    sync_certs: true
+    gen_certs: true
     secret_changed: false
 
 - name: "Check certs | check if a cert already exists on node"
@@ -25,7 +25,7 @@
 - name: "Check_certs | Set 'gen_certs' to true"
   set_fact:
     gen_certs: true
-  when: "not item in kubecert_master.files|map(attribute='path') | list"
+  when: "rotate_kubernetes_certs or item not in (kubecert_master.files|map(attribute='path')|list)"
   run_once: true
   with_items: >-
        ['{{ kube_cert_dir }}/ca.pem',
@@ -41,7 +41,7 @@
       {% set existing_certs = kubecert_master.files|map(attribute='path')|list|sort %}
       {% for host in groups['k8s-cluster'] -%}
         {% set host_cert = "%s/node-%s-key.pem"|format(kube_cert_dir, host) %}
-        {% if host_cert in existing_certs -%}
+        {% if host_cert in existing_certs and not rotate_kubernetes_certs -%}
         "{{ host }}": False,
         {% else -%}
         "{{ host }}": True,
@@ -62,5 +62,5 @@
             (kubecert_node.results[1].stat.checksum|default('') != kubecert_master.files|selectattr("path", "equalto", kubecert_node.results[1].stat.path)|map(attribute="checksum")|first|default('')) -%}
               {%- set _ = certs.update({'sync': True}) -%}
       {% endif %}
-      {{ certs.sync }}
+      {{ rotate_kubernetes_certs or certs.sync }}
 

roles/kubernetes/secrets/tasks/gen_certs_script.yml

@@ -136,7 +136,6 @@
 - name: Gen_certs | Unpack certs on masters
   shell: "base64 -d < {{ cert_tempfile.stdout }} | tar xz -C {{ kube_cert_dir }}"
   no_log: true
-  changed_when: false
   check_mode: no
   when: inventory_hostname in groups['kube-master'] and sync_certs|default(false) and
         inventory_hostname != groups['kube-master'][0]
@@ -154,7 +153,6 @@
   args:
     executable: /bin/bash
   no_log: true
-  changed_when: false
   check_mode: no
   when: inventory_hostname in groups['kube-node'] and
         sync_certs|default(false) and