prometheus: Add basic Prometheus role

README.md

@@ -13,6 +13,16 @@ Pull requests to fix obvious minor issues are welcome, but it's unlikely that an
 - [awstats](roles/awstats) - installs and configures the [AWStats](https://awstats.sourceforge.io/) web server log analyzer
 - [bind](roles/bind) - installs and configures the `bind9` DNS server as well as one or more zone files.
 - [nginx](roles/nginx) - installs and configures the [nginx](https://nginx.org/) web server
+- [prometheus](roles/prometheus) - installs and configures the [Prometheus](https://prometheus.io/) monitoring system & time series database
+
+## Playbooks
+
+The following playbooks executes the above roles:
+
+- [awstats](awstats.yaml)
+- [bind.yaml](bind.yaml)
+- [nginx.yaml](nginx.yaml)
+- [prometheus.yaml](prometheus.yaml)
 
 ## Ansible config
 

prometheus.yaml

@@ -0,0 +1,12 @@
+- name: Runs the prometheus role
+  hosts: all
+
+  pre_tasks:
+    - import_tasks: include/common_pre_tasks.yml
+
+  roles:
+    - role: prometheus
+
+  module_defaults:
+    apt:
+      force_apt_get: yes

roles/prometheus/defaults/main.yml

@@ -0,0 +1,7 @@
+prometheus_etc_prometheus_path: '{{ inventory_dir }}/overrides/{{ inventory_hostname }}/prometheus/etc/prometheus'
+
+#
+# Variables below this line typically do not have to be modified.
+#
+prometheus_yml_path: '{{ prometheus_etc_prometheus_path }}/prometheus.yml'
+prometheus_alerting_rules_yaml_path: '{{ prometheus_etc_prometheus_path }}/alerting_rules.yaml'

roles/prometheus/handlers/main.yml

@@ -0,0 +1,6 @@
+- name: Reload or start the Prometheus service
+  systemd:
+    name: prometheus.service
+    state: reloaded
+  listen: reload_prometheus
+  become: true

roles/prometheus/tasks/main.yml

@@ -0,0 +1,29 @@
+- name: Install/update Prometheus
+  ansible.builtin.package:
+    name:
+      - prometheus
+
+    # Deliberately not using 'state: latest' to avoid unexpected surprises when
+    # e.g. deploying updated configuration.
+    state: present
+  become: true
+
+- name: Copy prometheus.yml to /etc/prometheus
+  ansible.builtin.copy:
+    src: '{{ prometheus_yml_path }}'
+    dest: /etc/prometheus/prometheus.yml
+    owner: root
+    group: root
+    mode: 0644
+  become: true
+  notify: reload_prometheus
+
+- name: Copy alerting_rules.yaml to /etc/prometheus
+  ansible.builtin.copy:
+    src: '{{ prometheus_alerting_rules_yaml_path }}'
+    dest: /etc/prometheus/alerting_rules.yaml
+    owner: root
+    group: root
+    mode: 0644
+  become: true
+  notify: reload_prometheus