From 4054f1a02e2f082c597245e5f2f7a649df943b52 Mon Sep 17 00:00:00 2001
From: Thomas Kleinendorst <thomas@kleinendorst.info>
Date: Mon, 21 Oct 2024 09:43:27 +0200
Subject: [PATCH] Add Postgres monitoring for Prometheus

---
 roles/monitoring/vars/main/defaults.yml |  7 +++++++
 roles/podman-container/tasks/main.yml   |  3 +++
 roles/postgres/tasks/main.yml           | 16 ++++++++++++++++
 roles/postgres/vars/main/defaults.yml   |  1 +
 4 files changed, 27 insertions(+)

diff --git a/roles/monitoring/vars/main/defaults.yml b/roles/monitoring/vars/main/defaults.yml
index 8f698e3..2801ba6 100644
--- a/roles/monitoring/vars/main/defaults.yml
+++ b/roles/monitoring/vars/main/defaults.yml
@@ -11,6 +11,9 @@ prometheus_targets:
   grafana:
     - targets:
         - raspberry-pi-1.kleinendorst.info:3000
+  postgres:
+    - targets:
+        - raspberry-pi-1.kleinendorst.info:9187
 prometheus_web_listen_address: 127.0.0.1:9090
 prometheus_scrape_configs:
   - job_name: "prometheus"
@@ -25,6 +28,10 @@ prometheus_scrape_configs:
     file_sd_configs:
       - files:
           - "{{ prometheus_config_dir }}/file_sd/grafana.yml"
+  - job_name: "postgres"
+    file_sd_configs:
+      - files:
+          - "{{ prometheus_config_dir }}/file_sd/postgres.yml"
 prometheus_alertmanager_config:
   - static_configs:
       - targets:
diff --git a/roles/podman-container/tasks/main.yml b/roles/podman-container/tasks/main.yml
index d1dc6fb..230dfb9 100644
--- a/roles/podman-container/tasks/main.yml
+++ b/roles/podman-container/tasks/main.yml
@@ -13,6 +13,9 @@
 - name: Register current user in a variable
   ansible.builtin.set_fact:
     container_user: "{{ whoami.stdout }}"
+- name: Set default podman_simple_container_volumes if not provided
+  ansible.builtin.set_fact:
+    podman_simple_container_volumes: "{{ podman_simple_container_volumes | default([]) }}"
 - name: Create mount directories
   ansible.builtin.file:
     path: "/home/{{ container_user }}/{{ item.name }}"
diff --git a/roles/postgres/tasks/main.yml b/roles/postgres/tasks/main.yml
index 0301f87..1eb87b6 100644
--- a/roles/postgres/tasks/main.yml
+++ b/roles/postgres/tasks/main.yml
@@ -51,3 +51,19 @@
       - ssl_key_file=/var/lib/postgresql/privkey.pem
     podman_container_env:
       POSTGRES_PASSWORD: "{{ postgres_password }}"
+- name: Create the postgres prometheus exporter container
+  ansible.builtin.include_role:
+    name: podman-container
+    apply:
+      become: true
+      become_user: "{{ postgres_unix_username }}"
+  vars:
+    podman_container_name: postgres-prometheus-exporter
+    podman_container_image: quay.io/prometheuscommunity/postgres-exporter
+    podman_container_tag: "{{ postgres_prometheus_exporter_version }}"
+    podman_container_publish:
+      - 0.0.0.0:9187:9187
+    podman_container_env:
+      DATA_SOURCE_URI: "postgres.kleinendorst.info:5432/postgres"
+      DATA_SOURCE_USER: "postgres"
+      DATA_SOURCE_PASS: "{{ postgres_password }}"
diff --git a/roles/postgres/vars/main/defaults.yml b/roles/postgres/vars/main/defaults.yml
index 19cbd7e..be623b9 100644
--- a/roles/postgres/vars/main/defaults.yml
+++ b/roles/postgres/vars/main/defaults.yml
@@ -1,3 +1,4 @@
 ---
 postgres_unix_username: postgres
 postgres_version: 17-alpine
+postgres_prometheus_exporter_version: v0.15.0