From 71baae58bfeebb514a785a36356bc34b6297f3cd Mon Sep 17 00:00:00 2001
From: Yohann D'ANELLO <ynerant@crans.org>
Date: Tue, 9 Aug 2022 15:57:24 +0200
Subject: [PATCH] [bind] Export prometheus statistics

Signed-off-by: Yohann D'ANELLO <ynerant@crans.org>
---
 host_vars/fyre.adm.crans.org.yml                 | 15 +++++++++++++++
 hosts                                            |  4 ++++
 plays/monitoring.yml                             |  7 +++++++
 .../templates/bind/named.conf.options.j2         |  4 ++++
 .../templates/bind/named.conf.options.j2         |  4 ++++
 roles/prometheus-bind-exporter/handlers/main.yml |  5 +++++
 roles/prometheus-bind-exporter/tasks/main.yml    | 16 ++++++++++++++++
 7 files changed, 55 insertions(+)
 create mode 100644 roles/prometheus-bind-exporter/handlers/main.yml
 create mode 100644 roles/prometheus-bind-exporter/tasks/main.yml

diff --git a/host_vars/fyre.adm.crans.org.yml b/host_vars/fyre.adm.crans.org.yml
index 63f5d00e..d0fe3278 100644
--- a/host_vars/fyre.adm.crans.org.yml
+++ b/host_vars/fyre.adm.crans.org.yml
@@ -104,6 +104,21 @@ loc_prometheus:
             target_label: __address__
             replacement: '$1:9324'
 
+  bind:
+    config:
+      - job_name: bind
+        file_sd_configs:
+          - files:
+              - '/etc/prometheus/targets_bind.json'
+        relabel_configs:
+          - source_labels: [__address__]
+            target_label: __param_target
+          - source_labels: [__param_target]
+            target_label: instance
+          - source_labels: [__param_target]
+            target_label: __address__
+            replacement: '$1:9119'
+
   mtail:
     config:
       - job_name: mtail
diff --git a/hosts b/hosts
index 92170eea..ef386db3 100644
--- a/hosts
+++ b/hosts
@@ -25,6 +25,10 @@ tealc.adm.crans.org
 [belenios]
 belenios.adm.crans.org
 
+[bind:children]
+dns_authoritative
+dns_recursive
+
 [bird:children]
 routeurs_vm
 
diff --git a/plays/monitoring.yml b/plays/monitoring.yml
index b2407344..973a66cf 100755
--- a/plays/monitoring.yml
+++ b/plays/monitoring.yml
@@ -55,6 +55,13 @@
   roles:
     - prometheus-bird-exporter
 
+# Monitor Bind metrics
+- hosts: bind
+  vars:
+    prometheus_bind_exporter: "{{ glob_prometheus_bind_exporter | default({}) | combine(loc_prometheus_bind_exporter | default({})) }}"
+  roles:
+    - prometheus-bind-exporter
+
 # Monitor mailq with a special text exporter
 # - hosts: redisdead.adm.crans.org
 #   roles: ["prometheus-node-exporter-postfix"]
diff --git a/roles/bind-authoritative/templates/bind/named.conf.options.j2 b/roles/bind-authoritative/templates/bind/named.conf.options.j2
index f972196b..21336da6 100644
--- a/roles/bind-authoritative/templates/bind/named.conf.options.j2
+++ b/roles/bind-authoritative/templates/bind/named.conf.options.j2
@@ -51,3 +51,7 @@ options {
 	allow-transfer { none; };
 {% endif %}
 };
+
+statistics-channels {
+  inet 127.0.0.1 port 8053 allow { 127.0.0.1; };
+};
diff --git a/roles/bind-recursive/templates/bind/named.conf.options.j2 b/roles/bind-recursive/templates/bind/named.conf.options.j2
index 93497100..36a95afb 100644
--- a/roles/bind-recursive/templates/bind/named.conf.options.j2
+++ b/roles/bind-recursive/templates/bind/named.conf.options.j2
@@ -24,3 +24,7 @@ options {
 
 	listen-on-v6 { any; };
 };
+
+statistics-channels {
+  inet 127.0.0.1 port 8053 allow { 127.0.0.1; };
+};
diff --git a/roles/prometheus-bind-exporter/handlers/main.yml b/roles/prometheus-bind-exporter/handlers/main.yml
new file mode 100644
index 00000000..064fb934
--- /dev/null
+++ b/roles/prometheus-bind-exporter/handlers/main.yml
@@ -0,0 +1,5 @@
+---
+- name: Restart prometheus-bind-exporter
+  service:
+    name: prometheus-bind-exporter
+    state: restarted
diff --git a/roles/prometheus-bind-exporter/tasks/main.yml b/roles/prometheus-bind-exporter/tasks/main.yml
new file mode 100644
index 00000000..85df966a
--- /dev/null
+++ b/roles/prometheus-bind-exporter/tasks/main.yml
@@ -0,0 +1,16 @@
+---
+- name: Install Prometheus bind-exporter
+  apt:
+    update_cache: true
+    name: prometheus-bind-exporter
+  register: apt_result
+  retries: 3
+  until: apt_result is succeeded
+
+- name: Make Prometheus bind-exporter listen on adm only
+  lineinfile:
+    path: /etc/default/prometheus-bind-exporter
+    regexp: ^ARGS=
+    line: |
+      ARGS="--web.listen-address={{ prometheus_bind_exporter.listen_addr }}:9119"
+  notify: Restart prometheus-bind-exporter