Check K3s installed version before download tasks (#297)

- [Agent : Download artefact only if needed](roles/k3s_agent/tasks/main.yml#L13)
- [Server : Download artefact only if needed](roles/k3s_server/tasks/main.yml#L13)
- [Upgrade : Upgrade node only if needed](roles/k3s_upgrade/tasks/main.yml#L14)

Linked issue #264 k3s_server and k3s_agent tasks are not idempotent

Signed-off-by: Loïc Dubard <loic97429@gmail.com>

roles/k3s_agent/tasks/main.yml

@@ -1,7 +1,23 @@
 ---
+- name: Get k3s installed version
+  ansible.builtin.command: k3s --version
+  register: k3s_version_output
+  changed_when: false
+  ignore_errors: true
+
+- name: Set k3s installed version
+  when: k3s_version_output.rc == 0
+  ansible.builtin.set_fact:
+    installed_k3s_version: "{{ k3s_version_output.stdout_lines[0].split(' ')[2] }}"
+
 # If airgapped, all K3s artifacts are already on the node.
-- name: Download K3s install script
+# We should be downloading and installing the newer version only if we are in one of the following cases :
-  when: airgap_dir is undefined
+#   - we couldn't get k3s installed version in the first task of this role
+#   - the installed version of K3s on the nodes is older than the requested version in ansible vars
+- name: Download artefact only if needed
+  when: k3s_version_output.rc != 0 or installed_k3s_version is version(k3s_version, '<') and airgap_dir is undefined
+  block:
+    - name: Download K3s install script
       ansible.builtin.get_url:
         url: https://get.k3s.io/
         timeout: 120
@@ -10,8 +26,7 @@
         group: root
         mode: 0755
 
-- name: Download K3s binary
+    - name: Download K3s binary
-  when: airgap_dir is undefined
       ansible.builtin.command:
         cmd: /usr/local/bin/k3s-install.sh
       environment:

roles/k3s_server/tasks/main.yml

@@ -1,7 +1,23 @@
 ---
+- name: Get k3s installed version
+  ansible.builtin.command: k3s --version
+  register: k3s_version_output
+  changed_when: false
+  ignore_errors: true
+
+- name: Set k3s installed version
+  when: k3s_version_output.rc == 0
+  ansible.builtin.set_fact:
+    installed_k3s_version: "{{ k3s_version_output.stdout_lines[0].split(' ')[2] }}"
+
 # If airgapped, all K3s artifacts are already on the node.
-- name: Download K3s install script
+# We should be downloading and installing the newer version only if we are in one of the following cases :
-  when: airgap_dir is undefined
+#   - we couldn't get k3s installed version in the first task of this role
+#   - the installed version of K3s on the nodes is older than the requested version in ansible vars
+- name: Download artefact only if needed
+  when: k3s_version_output.rc != 0 or installed_k3s_version is version(k3s_version, '<') and airgap_dir is undefined
+  block:
+    - name: Download K3s install script
       ansible.builtin.get_url:
         url: https://get.k3s.io/
         timeout: 120
@@ -10,8 +26,7 @@
         group: root
         mode: 0755
 
-- name: Download K3s binary
+    - name: Download K3s binary
-  when: airgap_dir is undefined
       ansible.builtin.command:
         cmd: /usr/local/bin/k3s-install.sh
       environment:

roles/k3s_upgrade/tasks/main.yml

@@ -1,12 +1,26 @@
 ---
 # with_fileglob doesn't work with remote_src, it tries to find the file on the
 # local control-plane instead of the remote host. Shell supports wildcards.
-- name: Save current K3s service
+- name: Get k3s installed version
+  ansible.builtin.command: k3s --version
+  register: k3s_version_output
+  changed_when: false
+
+- name: Set k3s installed version
+  ansible.builtin.set_fact:
+    installed_k3s_version: "{{ k3s_version_output.stdout_lines[0].split(' ')[2] }}"
+
+# We should be downloading and installing the newer version only if we are in the following case :
+#   - the installed version of K3s on the nodes is older than the requested version in ansible vars
+- name: Update node only if needed
+  when: installed_k3s_version is version(k3s_version, '<')
+  block:
+    - name: Save current K3s service
       ansible.builtin.shell:
         cmd: "cp {{ systemd_dir }}/k3s*.service /tmp/"
       changed_when: true
 
-- name: Install new K3s Version
+    - name: Install new K3s Version
       ansible.builtin.command:
         cmd: /usr/local/bin/k3s-install.sh
       environment:
@@ -14,19 +28,19 @@
         INSTALL_K3S_VERSION: "{{ k3s_version }}"
       changed_when: true
 
-- name: Restore K3s service
+    - name: Restore K3s service
       ansible.builtin.shell:
         cmd: "mv /tmp/k3s*.service {{ systemd_dir }}/"
       changed_when: true
 
-- name: Restart K3s service [server]
+    - name: Restart K3s service [server]
       when: "'server' in group_names"
       ansible.builtin.systemd:
         state: restarted
         daemon_reload: true
         name: k3s
 
-- name: Restart K3s service [agent]
+    - name: Restart K3s service [agent]
       when: "'agent' in group_names"
       ansible.builtin.systemd:
         state: restarted