Upgrade to kubeadm (#1667)

* Enable upgrade to kubeadm

* fix kubedns upgrade

* try upgrade route

* use init/upgrade strategy for kubeadm and ignore kubedns svc

* Use bin_dir for kubeadm

* delete more secrets

* fix waiting for terminating pods

* Manually enforce kube-proxy for kubeadm deploy

* remove proxy. update to kubeadm 1.8.0rc1

.gitlab-ci.yml

@@ -299,12 +299,24 @@ before_script:
   UPGRADE_TEST: "graceful"
   STARTUP_SCRIPT: ""
 
+.centos_weave_kubeadm_variables: &centos_weave_kubeadm_variables
+# stage: deploy-gce-part1
+  KUBE_NETWORK_PLUGIN: weave
+  AUTHORIZATION_MODES: "{ 'authorization_modes':  [ 'RBAC' ] }"
+  CLOUD_IMAGE: centos-7
+  CLOUD_MACHINE_TYPE: "n1-standard-1"
+  CLOUD_REGION: us-central1-b
+  CLUSTER_MODE: ha
+  KUBEADM_ENABLED: "true"
+  UPGRADE_TEST: "graceful"
+  STARTUP_SCRIPT: ""
+
 .ubuntu_canal_kubeadm_variables: &ubuntu_canal_kubeadm_variables
 # stage: deploy-gce-part1
   KUBE_NETWORK_PLUGIN: canal
   AUTHORIZATION_MODES: "{ 'authorization_modes':  [ 'RBAC' ] }"
   CLOUD_IMAGE: ubuntu-1604-xenial
-  CLOUD_MACHINE_TYPE: "n1-standard-2"
+  CLOUD_MACHINE_TYPE: "n1-standard-1"
   CLOUD_REGION: europe-west1-b
   CLUSTER_MODE: ha
   KUBEADM_ENABLED: "true"
@@ -521,6 +533,27 @@ ubuntu-canal-kubeadm-triggers:
   when: on_success
   only: ['triggers']
 
+centos-weave-kubeadm-rbac:
+  stage: deploy-gce-part1
+  <<: *job
+  <<: *gce
+  variables:
+    <<: *gce_variables
+    <<: *centos_weave_kubeadm_variables
+  when: manual
+  except: ['triggers']
+  only: ['master', /^pr-.*$/]
+
+centos-weave-kubeadm-triggers:
+  stage: deploy-gce-part1
+  <<: *job
+  <<: *gce
+  variables:
+    <<: *gce_variables
+    <<: *centos_weave_kubeadm_variables
+  when: on_success
+  only: ['triggers']
+
 rhel7-weave:
   stage: deploy-gce-part1
   <<: *job

cluster.yml

@@ -80,6 +80,7 @@
   any_errors_fatal: "{{ any_errors_fatal | default(true) }}"
   roles:
     - { role: kubespray-defaults}
+    - { role: kubernetes-apps/rotate_tokens, tags: rotate_tokens, when: "secret_changed|default(false)" }
     - { role: kubernetes-apps/network_plugin, tags: network }
     - { role: kubernetes-apps/policy_controller, tags: policy-controller }
     - { role: kubernetes/client, tags: client }

docs/upgrades.md

@@ -67,3 +67,17 @@ follows:
 * network_plugin (such as Calico or Weave)
 * kube-apiserver, kube-scheduler, and kube-controller-manager
 * Add-ons (such as KubeDNS)
+
+#### Upgrade considerations
+
+Kubespray supports rotating certificates used for etcd and Kubernetes
+components, but some manual steps may be required. If you have a pod that
+requires use of a service token and is deployed in a namespace other than
+`kube-system`, you will need to manually delete the affected pods after
+rotating certificates. This is because all service account tokens are dependent
+on the apiserver token that is used to generate them. When the certificate
+rotates, all service account tokens must be rotated as well. During the
+kubernetes-apps/rotate_tokens role, only pods in kube-system are destroyed and
+recreated. All other invalidated service account tokens are cleaned up
+automatically, but other pods are not deleted out of an abundance of caution
+for impact to user deployed pods.

roles/download/defaults/main.yml

@@ -20,7 +20,7 @@ download_always_pull: False
 # Versions
 kube_version: v1.7.5
 # Change to kube_version after v1.8.0 release
-kubeadm_version: "v1.8.0-beta.1"
+kubeadm_version: "v1.8.0-rc.1"
 etcd_version: v3.2.4
 # TODO(mattymo): Move calico versions to roles/network_plugins/calico/defaults
 # after migration to container download
@@ -37,7 +37,7 @@ pod_infra_version: 3.0
 kubeadm_download_url: "https://storage.googleapis.com/kubernetes-release/release/{{ kubeadm_version }}/bin/linux/amd64/kubeadm"
 
 # Checksums
-kubeadm_checksum: "ddd5949699d6bdbc0b90b379e7e534f137b1058db1acc8f26cc54843f017ffbf"
+kubeadm_checksum: "8f6ceb26b8503bfc36a99574cf6f853be1c55405aa31669561608ad8099bf5bf"
 
 # Containers
 etcd_image_repo: "quay.io/coreos/etcd"
@@ -123,7 +123,7 @@ downloads:
     container: true
     repo: "{{ etcd_image_repo }}"
     tag: "{{ etcd_image_tag }}"
-    sha256: "{{etcd_digest_checksum|default(None)}}"
+    sha256: "{{ etcd_digest_checksum|default(None) }}"
   kubeadm:
     version: "{{ kubeadm_version }}"
     dest: "kubeadm"

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

@@ -8,7 +8,17 @@
   delay: 6
   when: inventory_hostname == groups['kube-master'][0]
 
-- name: kubeadm | Delete kubeadm kubedns
+- name: Kubernetes Apps | Delete old kubedns resources
+  kube:
+    name: "kubedns"
+    namespace: "{{ system_namespace }}"
+    kubectl: "{{bin_dir}}/kubectl"
+    resource: "{{ item }}"
+    state: absent
+  with_items: ['deploy', 'svc']
+  tags: upgrade
+
+- name: Kubernetes Apps | Delete kubeadm kubedns
   kube:
     name: "kubedns"
     namespace: "{{ system_namespace }}"
@@ -25,9 +35,9 @@
     src: "{{item.file}}"
     dest: "{{kube_config_dir}}/{{item.file}}"
   with_items:
-    - {name: kubedns, file: kubedns-sa.yml, type: sa}
-    - {name: kubedns, file: kubedns-deploy.yml.j2, type: deployment}
-    - {name: kubedns, file: kubedns-svc.yml, type: svc}
+    - {name: kube-dns, file: kubedns-sa.yml, type: sa}
+    - {name: kube-dns, file: kubedns-deploy.yml.j2, type: deployment}
+    - {name: kube-dns, 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}

roles/kubernetes-apps/network_plugin/weave/tasks/main.yml

@@ -1,15 +1,4 @@
 ---
-# FIXME: remove if kubernetes/features#124 is implemented
-- name: Weave | Purge old weave daemonset
-  kube:
-    name: "weave-net"
-    kubectl: "{{ bin_dir }}/kubectl"
-    filename: "{{ kube_config_dir }}/weave-net.yml"
-    resource: "ds"
-    namespace: "{{system_namespace}}"
-    state: absent
-  when: inventory_hostname == groups['kube-master'][0] and weave_manifest.changed
-
 - name: Weave | Start Resources
   kube:
     name: "weave-net"

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

@@ -0,0 +1,20 @@
+---
+#FIXME(mattymo): Exclude built in secrets that were automatically rotated,
+#instead of filtering manually
+- name: Rotate Tokens | Get all serviceaccount tokens to expire
+  shell: >-
+    {{ bin_dir }}/kubectl get secrets --all-namespaces
+    -o 'jsonpath={range .items[*]}{"\n"}{.metadata.namespace}{" "}{.metadata.name}{" "}{.type}{end}'
+    | grep kubernetes.io/service-account-token
+    | egrep 'default-token|kube-proxy|kube-dns|dnsmasq|netchecker|weave|calico|canal|flannel|dashboard|cluster-proportional-autoscaler|efk|tiller'
+  register: tokens_to_delete
+  run_once: true
+
+- name: Rotate Tokens | Delete expired tokens
+  command: "{{ bin_dir }}/kubectl delete secrets -n {{ item.split(' ')[0] }} {{ item.split(' ')[1] }}"
+  with_items: "{{ tokens_to_delete.stdout_lines }}"
+  run_once: true
+
+- name: Rotate Tokens | Delete pods in system namespace
+  command: "{{ bin_dir }}/kubectl delete pods -n {{ system_namespace }} --all"
+  run_once: true

roles/kubernetes/kubeadm/tasks/main.yml

@@ -24,7 +24,7 @@
   register: kubeadm_client_conf
 
 - name: Join to cluster if needed
-  command: kubeadm join --config {{ kube_config_dir}}/kubeadm-client.conf --skip-preflight-checks
+  command: "{{ bin_dir }}/kubeadm join --config {{ kube_config_dir}}/kubeadm-client.conf --skip-preflight-checks"
   register: kubeadm_join
   when: not is_kube_master and (kubeadm_client_conf.changed or not kubelet_conf.stat.exists)
 

roles/kubernetes/master/tasks/kubeadm-cleanup-old-certs.yml

@@ -0,0 +1,3 @@
+---
+- name: kubeadm | Purge old certs
+  command: "rm -f {{kube_cert_dir }}/*.pem"

roles/kubernetes/master/tasks/kubeadm-migrate-certs.yml

@@ -0,0 +1,12 @@
+---
+- name: Copy old certs to the kubeadm expected path
+  copy:
+    src: "{{ kube_cert_dir }}/{{ item.src }}"
+    dest: "{{ kube_cert_dir }}/{{ item.dest }}"
+    remote_src: yes
+  with_items:
+    - {src: apiserver.pem, dest: apiserver.crt}
+    - {src: apiserver.pem, dest: apiserver.key}
+    - {src: ca.pem, dest: ca.crt}
+    - {src: ca-key.pem, dest: ca.key}
+  register: kubeadm_copy_old_certs

roles/kubernetes/master/tasks/kubeadm-setup.yml

@@ -1,4 +1,35 @@
 ---
+- name: kubeadm | Check if old apiserver cert exists on host
+  stat:
+    path: "{{ kube_cert_dir }}/apiserver.pem"
+  register: old_apiserver_cert
+  delegate_to: "{{groups['kube-master']|first}}"
+  run_once: true
+
+- name: kubeadm | Check service account key
+  stat:
+    path: "{{ kube_cert_dir }}/sa.key"
+  register: sa_key_before
+  delegate_to: "{{groups['kube-master']|first}}"
+  run_once: true
+
+- name: kubeadm | Check if kubeadm has already run
+  stat:
+    path: "{{ kube_config_dir }}/admin.conf"
+  register: admin_conf
+
+- name: kubeadm | Delete old static pods
+  file:
+    path: "{{ kube_config_dir }}/manifests/{{item}}.manifest"
+    state: absent
+  with_items: ["kube-apiserver", "kube-controller-manager", "kube-scheduler", "kube-proxy"]
+  when: old_apiserver_cert.stat.exists
+
+- name: kubeadm | Forcefully delete old static pods
+  shell: "docker ps -f name=k8s_{{item}} -q | xargs --no-run-if-empty docker rm -f"
+  with_items: ["kube-apiserver", "kube-controller-manager", "kube-scheduler"]
+  when: old_apiserver_cert.stat.exists
+
 - name: kubeadm | aggregate all SANs
   set_fact:
     apiserver_sans: >-
@@ -29,18 +60,29 @@
     dest: "{{ kube_config_dir }}/kubeadm-config.yaml"
   register: kubeadm_config
 
-- name: Check if kubeadm has already run
-  stat:
-    path: "{{ kube_config_dir }}/admin.conf"
-  register: admin_conf
-
-
 - name: kubeadm | Initialize first master
-  command: timeout -k 240s 240s kubeadm init --config={{ kube_config_dir }}/kubeadm-config.yaml --skip-preflight-checks
+  command: timeout -k 240s 240s {{ bin_dir }}/kubeadm init --config={{ kube_config_dir }}/kubeadm-config.yaml --skip-preflight-checks
   register: kubeadm_init
   #Retry is because upload config sometimes fails
   retries: 3
-  when: inventory_hostname == groups['kube-master']|first and (kubeadm_config.changed or not admin_conf.stat.exists)
+  when: inventory_hostname == groups['kube-master']|first and not admin_conf.stat.exists
+  failed_when: kubeadm_init.rc != 0 and "field is immutable" not in kubeadm_init.stderr
+  notify: Master | restart kubelet
+
+- name: kubeadm | Upgrade first master
+  command: timeout -k 240s 240s {{ bin_dir }}/kubeadm upgrade apply --config={{ kube_config_dir }}/kubeadm-config.yaml {{ kube_version }} --skip-preflight-checks
+  register: kubeadm_upgrade
+  #Retry is because upload config sometimes fails
+  retries: 3
+  when: inventory_hostname == groups['kube-master']|first and (kubeadm_config.changed and admin_conf.stat.exists)
+  failed_when: kubeadm_upgrade.rc != 0 and "field is immutable" not in kubeadm_upgrade.stderr
+  notify: Master | restart kubelet
+
+# FIXME(mattymo): remove when https://github.com/kubernetes/kubeadm/issues/433 is fixed
+- name: kubeadm | Enable kube-proxy
+  command: "{{ bin_dir }}/kubeadm alpha phase addon kube-proxy --config={{ kube_config_dir }}/kubeadm-config.yaml"
+  when: inventory_hostname == groups['kube-master']|first
+  changed_when: false
 
 - name: slurp kubeadm certs
   slurp:
@@ -62,7 +104,7 @@
   delegate_to: "{{ groups['kube-master']|first }}"
   run_once: true
 
-- name: write out kubeadm certs
+- name: kubeadm | write out kubeadm certs
   copy:
     dest: "{{ item.item }}"
     content: "{{ item.content | b64decode }}"
@@ -74,9 +116,32 @@
   with_items: "{{ kubeadm_certs.results }}"
   when: inventory_hostname != groups['kube-master']|first
 
-- name: kubeadm | Initialize other masters
-  command: timeout -k 240s 240s kubeadm init --config={{ kube_config_dir }}/kubeadm-config.yaml --skip-preflight-checks
+- name: kubeadm | Init other uninitialized masters
+  command: timeout -k 240s 240s {{ bin_dir }}/kubeadm init --config={{ kube_config_dir }}/kubeadm-config.yaml --skip-preflight-checks
   register: kubeadm_init
-  #Retry is because upload config sometimes fails
-  retries: 3
-  when: inventory_hostname != groups['kube-master']|first and (kubeadm_config.changed or not admin_conf.stat.exists or copy_kubeadm_certs.changed)
+  when: inventory_hostname != groups['kube-master']|first and not admin_conf.stat.exists
+  failed_when: kubeadm_init.rc != 0 and "field is immutable" not in kubeadm_init.stderr
+  notify: Master | restart kubelet
+
+- name: kubeadm | Upgrade other masters
+  command: timeout -k 240s 240s {{ bin_dir }}/kubeadm upgrade apply --config={{ kube_config_dir }}/kubeadm-config.yaml {{ kube_version }} --skip-preflight-checks
+  register: kubeadm_upgrade
+  when: inventory_hostname != groups['kube-master']|first and (kubeadm_config.changed and admin_conf.stat.exists)
+  failed_when: kubeadm_upgrade.rc != 0 and "field is immutable" not in kubeadm_upgrade.stderr
+  notify: Master | restart kubelet
+
+- name: kubeadm | Check service account key again
+  stat:
+    path: "{{ kube_cert_dir }}/sa.key"
+  register: sa_key_after
+  delegate_to: "{{groups['kube-master']|first}}"
+  run_once: true
+
+- name: kubeadm | Set secret_changed if service account key was updated
+  command: /bin/true
+  notify: Master | set secret_changed
+  when: sa_key_before.stat.checksum|default("") != sa_key_after.stat.checksum
+
+- name: kubeadm | cleanup old certs if necessary
+  include: kubeadm-cleanup-old-certs.yml
+  when: old_apiserver_cert.stat.exists

roles/kubernetes/master/templates/kubeadm-config.yaml.j2

@@ -17,7 +17,6 @@ networking:
   podSubnet: {{ kube_pods_subnet }}
 kubernetesVersion: {{ kube_version }}
 cloudProvider: {{ cloud_provider|default('') }}
-#TODO: cloud provider conf file
 authorizationModes:
 - Node
 {% for mode in authorization_modes %}
@@ -53,7 +52,6 @@ apiServerExtraArgs:
   runtime-config: {{ kube_api_runtime_config }}
 {% endif %}
   allow-privileged: "true"
-#TODO: Custom flags compatible with kubeadm
 controllerManagerExtraArgs:
   node-monitor-grace-period: {{ kube_controller_node_monitor_grace_period }}
   node-monitor-period: {{ kube_controller_node_monitor_period }}
@@ -61,7 +59,6 @@ controllerManagerExtraArgs:
 {% if kube_feature_gates %}
   feature-gates: {{ kube_feature_gates|join(',') }}
 {% endif %}
-#schedulerExtraArgs:
 apiServerCertSANs:
 {% for san in  apiserver_sans.split(' ') | unique %}
   - {{ san }}

roles/kubernetes/node/tasks/install.yml

@@ -19,12 +19,20 @@
   when: kubeadm_enabled
   tags: kubeadm
 
-- name: install | Copy binary from download dir
+- name: install | Copy kubeadm binary from download dir
   command: rsync -piu "{{ local_release_dir }}/kubeadm" "{{ bin_dir }}/kubeadm"
   changed_when: false
   when: kubeadm_enabled
   tags: kubeadm
 
+- name: install | Set kubeadm binary permissions
+  file:
+    path: "{{ bin_dir }}/kubeadm"
+    mode: "0755"
+    state: file
+  when: kubeadm_enabled
+  tags: kubeadm
+
 - include: "install_{{ kubelet_deployment_type }}.yml"
 
 - name: install | Write kubelet systemd init file

roles/kubernetes/node/tasks/main.yml

@@ -96,6 +96,13 @@
   when: not kubeadm_enabled
   tags: kube-proxy
 
+- name: Purge proxy manifest for kubeadm
+  file:
+    path: "{{ kube_manifest_dir }}/kube-proxy.manifest"
+    state: absent
+  when: kubeadm_enabled
+  tags: kube-proxy
+
 # reload-systemd
 - meta: flush_handlers
 

roles/reset/tasks/main.yml

@@ -75,6 +75,7 @@
   with_items:
     - "{{kube_config_dir}}"
     - /var/lib/kubelet
+    - /root/.kube
     - "{{ etcd_data_dir }}"
     - /etc/ssl/etcd
     - /var/log/calico

tests/testcases/030_check-network.yml

@@ -13,12 +13,20 @@
     when: not ansible_os_family in ["CoreOS", "Container Linux by CoreOS"]
 
 
+  - name: Wait for pods to be ready
+    shell: "{{bin_dir}}/kubectl get pods"
+    register: pods
+    until:
+      - '"ContainerCreating" not in pods.stdout'
+      - '"Pending" not in pods.stdout'
+      - '"Terminating" not in pods.stdout'
+    retries: 60
+    delay: 2
+    no_log: true
+
   - name: Get pod names
     shell: "{{bin_dir}}/kubectl get pods -o json"
     register: pods
-    until: '"ContainerCreating" not in pods.stdout and "Terminating" not in pods.stdout'
-    retries: 60
-    delay: 2
     no_log: true
 
   - name: Get hostnet pods

upgrade-cluster.yml

@@ -67,7 +67,6 @@
     - { role: kubernetes/node, tags: node }
     - { role: kubernetes/master, tags: master }
     - { role: network_plugin, tags: network }
-    - { role: kubernetes/kubeadm, tags: kubeadm, when: "kubeadm_enabled" }
     - { role: upgrade/post-upgrade, tags: post-upgrade }
 
 #Finally handle worker upgrades, based on given batch size
@@ -87,6 +86,7 @@
   any_errors_fatal: true
   roles:
     - { role: kubespray-defaults}
+    - { role: kubernetes-apps/rotate_tokens, tags: rotate_tokens, when: "secret_changed|default(false)" }
     - { role: kubernetes-apps/network_plugin, tags: network }
     - { role: kubernetes-apps/policy_controller, tags: policy-controller }
     - { role: kubernetes/client, tags: client }