Remove access to cluster from anonymous users (#11016)

* feat: add user facing variable with default

* feat: remove rolebinding to anonymous users after init and upgrade

* feat: use file discovery for secondary control plane nodes

* feat: use file discovery for nodes

* fix: do not fail if rolebinding does not exist

* docs: add warning about kube_api_anonymous_auth

* style: improve readability of delegate_to parameter

* refactor: rename discovery kubeconfig file

* test: enable new variable in hardening and upgrade test cases

* docs: add option to config parameters

* test: multiple instances and upgrade

roles/kubernetes/control-plane/tasks/kubeadm-secondary.yml

@@ -63,6 +63,26 @@
     - kubeadm_already_run is not defined or not kubeadm_already_run.stat.exists
     - not kube_external_ca_mode
 
+- name: Get kubeconfig for join discovery process
+  command: "{{ kubectl }} -n kube-public get cm cluster-info -o jsonpath='{.data.kubeconfig}'"
+  register: kubeconfig_file_discovery
+  run_once: true
+  delegate_to: "{{ groups['kube_control_plane'] | first }}"
+  when:
+    - kubeadm_use_file_discovery
+    - kubeadm_already_run is not defined or not kubeadm_already_run.stat.exists
+
+- name: Copy discovery kubeconfig
+  copy:
+    dest: "{{ kube_config_dir }}/cluster-info-discovery-kubeconfig.yaml"
+    content: "{{ kubeconfig_file_discovery.stdout }}"
+    owner: "root"
+    mode: 0644
+  when:
+    - inventory_hostname != first_kube_control_plane
+    - kubeadm_use_file_discovery
+    - kubeadm_already_run is not defined or not kubeadm_already_run.stat.exists
+
 - name: Joining control plane node to the cluster.
   command: >-
     {{ bin_dir }}/kubeadm join

roles/kubernetes/control-plane/tasks/kubeadm-setup.yml

@@ -221,12 +221,16 @@
     {{ bin_dir }}/kubeadm --kubeconfig {{ kube_config_dir }}/admin.conf token create {{ kubeadm_token }}
   changed_when: false
   when:
-    - inventory_hostname ==  first_kube_control_plane
+    - inventory_hostname == first_kube_control_plane
     - kubeadm_token is defined
     - kubeadm_refresh_token
   tags:
     - kubeadm_token
 
+- name: Remove binding to anonymous user
+  command: "{{ kubectl }} -n kube-public delete rolebinding kubeadm:bootstrap-signer-clusterinfo --ignore-not-found"
+  when: inventory_hostname == first_kube_control_plane and remove_anonymous_access
+
 - name: Create kubeadm token for joining nodes with 24h expiration (default)
   command: "{{ bin_dir }}/kubeadm --kubeconfig {{ kube_config_dir }}/admin.conf token create"
   changed_when: false

roles/kubernetes/control-plane/tasks/kubeadm-upgrade.yml

@@ -53,6 +53,10 @@
     PATH: "{{ bin_dir }}:{{ ansible_env.PATH }}"
   notify: Master | restart kubelet
 
+- name: Kubeadm | Remove binding to anonymous user
+  command: "{{ kubectl }} -n kube-public delete rolebinding kubeadm:bootstrap-signer-clusterinfo --ignore-not-found"
+  when: remove_anonymous_access
+
 - name: Kubeadm | clean kubectl cache to refresh api types
   file:
     path: "{{ item }}"