Preflight check of single node-exporter installation

ansible/playbooks/roles/node_exporter/tasks/install-node-exporter-as-daemonset.yml → ansible/playbooks/roles/node_exporter/tasks/apply/install-node-exporter-as-daemonset.yml

@@ -1,13 +1,10 @@
 ---
-
 - name: Prepare configuration and upgrade/install Node-Exporter's Helm chart
   vars:
     # Handling "undefined", "null", "empty" and "boolean" values all at once.
     disable_helm_chart_bool: "{{ specification.disable_helm_chart | default(false, true) | bool }}"
-
     # Handling "undefined", "null" and "empty" values all at once.
     helm_chart_values_bool: "{{ specification.helm_chart_values | default(false) | ternary(true, false) }}"
-
   delegate_to: localhost
   become: false
   run_once: true
@@ -26,7 +23,7 @@
         repository_url: "{{ custom_repository_url | default('http://localhost/epirepo', true) }}"
 
     - when: helm_chart_values_bool
-    # IF `helm_chart_values`
+      # IF `helm_chart_values`
       block:
         - name: Copy Node-Exporter's Helm chart's custom configuration to file
           copy:
@@ -35,17 +32,17 @@
 
         - name: Install Node-Exporter's Helm chart (with custom values.yaml)
           delegate_to: localhost
-          shell: |
+          command: |
             helm -n {{ monitoring_chart_namespace }} upgrade --install \
               -f {{ download_directory }}/{{ node_exporter_helm_chart_name }}_values.yaml \
               {{ node_exporter_helm_chart_name }} \
               {{ download_directory }}/{{ exporter_chart_file_name }} --create-namespace
 
     - when: not helm_chart_values_bool
-    # ELSE
+      # ELSE
       block:
         - name: Install Node-Exporter's Helm chart (with default values.yaml)
-          shell: |
+          command: |
             helm -n {{ monitoring_chart_namespace }} upgrade --install \
               {{ node_exporter_helm_chart_name }} \
               {{ download_directory }}/{{ exporter_chart_file_name }} --create-namespace

ansible/playbooks/roles/node_exporter/tasks/install-node-exporter-as-system-service.yml → ansible/playbooks/roles/node_exporter/tasks/apply/install-node-exporter-as-system-service.yml

@@ -1,5 +1,4 @@
 ---
-
 - name: Create node_exporter system group
   group:
     name: node_exporter
@@ -43,7 +42,7 @@
     src: "{{ download_directory }}/{{ exporter_file_name }}"
     dest: "/opt/node_exporter"
     creates: "/opt/node_exporter/node_exporter"
-    extra_opts: [--strip-components=1]
+    extra_opts: [ --strip-components=1 ]
     mode: u=rwx,g=rx,o=rx
     owner: root
     group: node_exporter

ansible/playbooks/roles/node_exporter/tasks/uninstall-node-exporter-as-daemonset.yml → ansible/playbooks/roles/node_exporter/tasks/apply/uninstall-node-exporter-as-daemonset.yml

@@ -1,9 +1,6 @@
 ---
-
 - name: "Uninstall Helm release {{ node_exporter_helm_chart_name }} from {{ node_exporter_release_ns }} ns"
-
   delegate_to: localhost
   become: false
   run_once: true
-
   command: "helm uninstall -n {{ node_exporter_release_ns }} {{ node_exporter_helm_chart_name }}"

ansible/playbooks/roles/node_exporter/tasks/main.yml

@@ -1,8 +1,7 @@
 ---
-
 - name: Include installation tasks for Node Exporter as System Service
-  include_tasks: install-node-exporter-as-system-service.yml
+  include_tasks: apply/install-node-exporter-as-system-service.yml
 
 - name: Include installation tasks for Node Exporter as DaemonSet for "k8s as cloud service"
   when: k8s_as_cloud_service is defined and k8s_as_cloud_service
-  include_tasks: install-node-exporter-as-daemonset.yml
+  include_tasks: apply/install-node-exporter-as-daemonset.yml

ansible/playbooks/roles/node_exporter/tasks/preflight/upgrade.yml

@@ -0,0 +1,23 @@
+---
+- name: Check that only one Node Exporter Helm release is installed
+  run_once: true
+  block:
+    - name: Include defaults from node_exporter role
+      include_vars:
+        file: roles/node_exporter/defaults/main.yml
+        name: exporter_defaults
+
+    - name: Get information about node-exporter helm releases
+      become: true
+      command: "helm list --all-namespaces --output json --filter {{ exporter_defaults.node_exporter_helm_chart_name }}"
+      register: node_exporter_helm_list
+      changed_when: false
+
+    - name: Assert node-exported installed only in one namespace
+      assert:
+        that: node_exporter_helm_list.stdout_lines|length == 1
+        fail_msg: |
+          Multiple Helm installations of Node Exporter are not supported or there is nothing to upgrade.
+          `helm list` output:
+          {{ node_exporter_helm_list.stdout_lines }}
+        success_msg: There is only one Node Exporter release.

ansible/playbooks/roles/upgrade/tasks/node-exporter.yml → ansible/playbooks/roles/node_exporter/tasks/upgrade/main.yml

@@ -1,14 +1,16 @@
 ---
 - name: Node Exporter | Include defaults from node_exporter role
   include_vars:
-    file: roles/node_exporter/defaults/main.yml
+    file: defaults/main.yml
     name: exporter_defaults
 
 - name: Node Exporter | Include specification vars from node_exporter role
   include_vars:
-    file: roles/node_exporter/vars/main.yml
+    file: vars/main.yml
     name: exporter_vars
 
+# Re-installation in a different namespace was added in Epiphany v1.3
+# Everything related to that topic can be removed when versions before 1.3 are unsupported, including preflight checks
 - name: Node Exporter as DaemonSet | Prepare fact about helm release and reinstall daemonset if release exists
   delegate_to: localhost
   become: false
@@ -86,6 +88,7 @@
 - name: Node Exporter as System Service | Collect version
   shell: >-
     /opt/node_exporter/node_exporter --version 2>&1
+  changed_when: false
   register: exporter_current_version_out
 
 - name: Node Exporter as System Service | Set exporter_current_version fact
@@ -140,7 +143,7 @@
         src: "{{ download_directory }}/{{ exporter_file_name }}"
         dest: /opt/node_exporter
         creates: /opt/node_exporter/node_exporter
-        extra_opts: [--strip-components=1]
+        extra_opts: [ --strip-components=1 ]
         mode: u=rwx,go=rx
         owner: root
         group: node_exporter

ansible/playbooks/roles/preflight/tasks/upgrade.yml

@@ -21,3 +21,11 @@
     - groups.postgresql is defined
     - groups.postgresql | length > 0
     - "'postgresql' in group_names" # run only on PostgreSQL hosts
+
+- name: Node Exporter in K8s checks
+  include_tasks: roles/node_exporter/tasks/preflight/upgrade.yml
+  when:
+    - "'node_exporter' in upgrade_components or upgrade_components|length == 0"
+    - k8s_as_cloud_service is defined and k8s_as_cloud_service
+    - "'node_exporter' in group_names"
+    - "'kubernetes_master' in group_names"

ansible/playbooks/upgrade.yml

@@ -280,9 +280,9 @@
   become: true
   become_method: sudo
   tasks:
-    - import_role:
-        name: upgrade
-        tasks_from: node-exporter
+    - include_role:
+        name: node_exporter
+        tasks_from: upgrade/main
       when: "'node_exporter' in upgrade_components or upgrade_components|length == 0"
   environment:
     KUBECONFIG: "{{ kubeconfig.local }}"