fix(k3s-server): serialize control-plane joins

- Wait for each additional master to register before starting the next\n- Keep k3s initialization diagnostics bounded and sanitized

roles/k3s_server/tasks/fetch_k3s_init_logs.yml

@@ -9,6 +9,7 @@
       --unit=k3s-init.service --since=-30min --lines=5000
   changed_when: false
   failed_when: false
+  no_log: true
   register: k3s_init_log
 
 - name: Fetch k3s-init.service status
@@ -38,7 +39,9 @@
     dest: "{{ log_destination }}/k3s-init@{{ ansible_hostname }}.log"
     mode: "0644"
   vars:
-    content: >-
-      {{ ('=== k3s-init.service status ===\n' + k3s_init_status.stdout
-      + '\n\n=== k3s-init.service journal ===\n' + k3s_init_log.stdout)
-      | regex_replace('--token(?:=|\\s+)[^\\s]+', '--token ***') }}
+    content: |
+      === k3s-init.service status ===
+      {{ k3s_init_status.stdout | regex_replace('--token(?:=| +)[^ ]+', '--token ***') }}
+
+      === k3s-init.service journal ===
+      {{ k3s_init_log.stdout | regex_replace('--token(?:=| +)[^ ]+', '--token ***') }}

roles/k3s_server/tasks/join_master.yml

@@ -0,0 +1,27 @@
+---
+- name: Verify primary Kubernetes API is reachable from {{ joining_master }}
+  ansible.builtin.wait_for:
+    host: "{{ hostvars[groups[group_name_master | default('master')][0]].k3s_node_ip | split(',') | first }}"
+    port: 6443
+    connect_timeout: 5
+    timeout: "{{ retry_count | default(20) * 2 }}"
+  delegate_to: "{{ joining_master }}"
+
+- name: Join transient k3s-init service for {{ joining_master }}
+  ansible.builtin.command:
+    cmd: >-
+      systemd-run -p RestartSec=2 -p Restart=on-failure --unit=k3s-init
+      k3s server {{ hostvars[joining_master].server_init_args }}
+    creates: "{{ systemd_dir }}/k3s-init.service"
+  delegate_to: "{{ joining_master }}"
+
+- name: Wait for primary registration of {{ joining_master }}
+  ansible.builtin.command:
+    cmd: >-
+      {{ k3s_kubectl_binary | default('k3s kubectl') }} get node {{ joining_master }}
+  delegate_to: "{{ groups[group_name_master | default('master')][0] }}"
+  register: joined_master
+  until: joined_master.rc == 0
+  retries: "{{ retry_count | default(20) }}"
+  delay: 2
+  changed_when: false

roles/k3s_server/tasks/main.yml

@@ -51,13 +51,13 @@
   run_once: true
   when: groups[group_name_master | default('master')] | length > 1
 
-- name: Join additional masters inside the transient k3s-init service
-  ansible.builtin.command:
-    cmd: systemd-run -p RestartSec=2 -p Restart=on-failure --unit=k3s-init k3s server {{ server_init_args }}
-    creates: "{{ systemd_dir }}/k3s-init.service"
-  when:
-    - groups[group_name_master | default('master')] | length > 1
-    - ansible_hostname != hostvars[groups[group_name_master | default('master')][0]]['ansible_hostname']
+- name: Join additional masters one at a time
+  ansible.builtin.include_tasks: join_master.yml
+  loop: "{{ groups[group_name_master | default('master')][1:] }}"
+  loop_control:
+    loop_var: joining_master
+  run_once: true
+  when: groups[group_name_master | default('master')] | length > 1
 
 - name: Verification
   when: not ansible_check_mode