Add monitoring

Signed-off-by: Yohann D'ANELLO <ynerant@crans.org>

roles/prometheus-node-exporter/tasks/main.yml

@@ -0,0 +1,45 @@
+---
+- name: Install Prometheus node-exporter
+  apt:
+    update_cache: true
+    name: prometheus-node-exporter
+    install_recommends: false  # Do not install smartmontools
+  register: apt_result
+  retries: 3
+  until: apt_result is succeeded
+
+- name: Install Prometheus node-exporter-collectors (bullseye)
+  apt:
+    update_cache: true
+    name: prometheus-node-exporter-collectors
+    install_recommends: false
+  register: apt_result
+  retries: 3
+  until: apt_result is succeeded
+  when:
+    - ansible_lsb.codename == 'bullseye'
+
+- name: Make Prometheus node-exporter listen on adm only
+  lineinfile:
+    path: /etc/default/prometheus-node-exporter
+    regexp: '^ARGS='
+    line: |
+      ARGS="--web.listen-address={{ prometheus_node_exporter.listen_addr }}:9100"
+  tags: restart-node-exporter
+
+- name: Activate prometheus-node-exporter service
+  systemd:
+    name: prometheus-node-exporter
+    enabled: true
+    state: started
+
+# Install new APT textfile collector, it might be upstreamed one day
+# https://github.com/prometheus-community/node-exporter-textfile-collector-scripts/pull/35
+- name: Patch APT textfile collector
+  copy:
+    src: apt.sh
+    dest: /usr/share/prometheus-node-exporter/apt.sh
+    owner: root
+    group: root
+    mode: 0755
+  when: ansible_distribution_release != "bullseye"