From 993e29c0fe94ce41cc8bf1294fe88f313fc84633 Mon Sep 17 00:00:00 2001
From: "Dustin C. Hatch" <dustin@hatch.name>
Date: Thu, 11 Aug 2022 21:39:50 -0500
Subject: [PATCH] r/scrape-collectd: collectd scrape targets config

The *scrape-collectd* role generates the
`/etc/prometheus/scrape-collectd.yml` file.  This file can be read by
Prometheus/Victoria Metrics/vmagent to identify the hosts running
*collectd* with the *write_prometheus* plugin, using the
`files_sd_configs` scrape configuration option.

All hosts in the *collectd-prometheus* group are listed as scrape
targets.
---
 metricspi.yml                        | 4 ++++
 roles/scrape-collectd/tasks/main.yml | 8 ++++++++
 roles/scrape-collectd/vars/main.yml  | 2 ++
 3 files changed, 14 insertions(+)
 create mode 100644 roles/scrape-collectd/tasks/main.yml
 create mode 100644 roles/scrape-collectd/vars/main.yml

diff --git a/metricspi.yml b/metricspi.yml
index 45bcbcc..18da9d2 100644
--- a/metricspi.yml
+++ b/metricspi.yml
@@ -14,3 +14,7 @@
 - import_playbook: victoria-metrics.yml
 - import_playbook: alertmanager.yml
 - import_playbook: grafana.yml
+
+- hosts: metricspi
+  roles:
+  - scrape-collectd
diff --git a/roles/scrape-collectd/tasks/main.yml b/roles/scrape-collectd/tasks/main.yml
new file mode 100644
index 0000000..c6f5667
--- /dev/null
+++ b/roles/scrape-collectd/tasks/main.yml
@@ -0,0 +1,8 @@
+- name: ensure scrape hosts file is populated
+  copy:
+    dest: /etc/prometheus/scrape-collectd.yml
+    content: |+
+      {{ scrape_collectd_config | to_nice_yaml }}
+    mode: u=rw,go=r
+    owner: root
+    group: root
diff --git a/roles/scrape-collectd/vars/main.yml b/roles/scrape-collectd/vars/main.yml
new file mode 100644
index 0000000..eaaa6e7
--- /dev/null
+++ b/roles/scrape-collectd/vars/main.yml
@@ -0,0 +1,2 @@
+scrape_collectd_config:
+- targets: '{{ groups["collectd-prometheus"] }}'