From 50beedbc629743dde2dc4a052cd66b4c065496b6 Mon Sep 17 00:00:00 2001
From: lilly <li@lly.sh>
Date: Wed, 6 May 2026 15:51:08 +0200
Subject: [PATCH] configure metric scraping from knot on auth-dns

---
 .../chaosknoten/host_vars/auth-dns.yaml       |  2 ++
 inventories/chaosknoten/hosts.yaml            |  1 +
 .../auth-dns/alloy/knot-exporter.alloy        |  6 ++++++
 roles/knot/handlers/main.yaml                 |  8 +++++++
 roles/knot/tasks/03-configure-exporter.yaml   | 21 +++++++++++++++++++
 roles/knot/tasks/main.yaml                    |  1 +
 roles/knot/templates/knot-exporter.service.j2 | 17 +++++++++++++++
 7 files changed, 56 insertions(+)
 create mode 100644 resources/chaosknoten/auth-dns/alloy/knot-exporter.alloy
 create mode 100644 roles/knot/tasks/03-configure-exporter.yaml
 create mode 100644 roles/knot/templates/knot-exporter.service.j2

diff --git a/inventories/chaosknoten/host_vars/auth-dns.yaml b/inventories/chaosknoten/host_vars/auth-dns.yaml
index bff4b10..970e2f8 100644
--- a/inventories/chaosknoten/host_vars/auth-dns.yaml
+++ b/inventories/chaosknoten/host_vars/auth-dns.yaml
@@ -1,6 +1,8 @@
 ---
 deploy_systemd_resolved_config__enable: false
 
+alloy_config_additional: "{{ lookup('ansible.builtin.template', 'resources/chaosknoten/auth-dns/alloy/knot-exporter.alloy') }}"
+
 knot__dnssec_key_id: "auth-dns.hamburg.ccc.de-1"
 knot__remotes:
   - id: ns-intern.hamburg.ccc.de
diff --git a/inventories/chaosknoten/hosts.yaml b/inventories/chaosknoten/hosts.yaml
index a6cea9b..9dab323 100644
--- a/inventories/chaosknoten/hosts.yaml
+++ b/inventories/chaosknoten/hosts.yaml
@@ -224,6 +224,7 @@ alloy_hosts:
     spaceapiccc:
     www2:
     www3:
+    auth-dns:
 infrastructure_authorized_keys_hosts:
   hosts:
     ccchoir:
diff --git a/resources/chaosknoten/auth-dns/alloy/knot-exporter.alloy b/resources/chaosknoten/auth-dns/alloy/knot-exporter.alloy
new file mode 100644
index 0000000..1e532a1
--- /dev/null
+++ b/resources/chaosknoten/auth-dns/alloy/knot-exporter.alloy
@@ -0,0 +1,6 @@
+prometheus.scrape "knot_exporter" {
+    targets = [
+        {"__address__" = "localhost:9433", "instance" = "{{ ansible_facts['hostname'] }}"},
+    ]
+    forward_to = [ prometheus.relabel.chaosknoten_common.receiver ]
+}
diff --git a/roles/knot/handlers/main.yaml b/roles/knot/handlers/main.yaml
index f89fedd..38fce75 100644
--- a/roles/knot/handlers/main.yaml
+++ b/roles/knot/handlers/main.yaml
@@ -11,3 +11,11 @@
   become: true
   changed_when: true
   ansible.builtin.command: "netplan apply"
+
+- name: restart knot-exporter
+  tags: [ auth-dns ]
+  become: true
+  ansible.builtin.systemd:
+    name: knot-exporter.service
+    state: restarted
+    daemon_reload: true
diff --git a/roles/knot/tasks/03-configure-exporter.yaml b/roles/knot/tasks/03-configure-exporter.yaml
new file mode 100644
index 0000000..db5d830
--- /dev/null
+++ b/roles/knot/tasks/03-configure-exporter.yaml
@@ -0,0 +1,21 @@
+- name: Deploy knot-exporter systemd unit
+  tags: [ auth-dns ]
+  become: true
+  register: deploy_service_file
+  notify: restart knot-exporter
+  ansible.builtin.template:
+    src: knot-exporter.service.j2
+    dest: /etc/systemd/system/knot-exporter.service
+    owner: root
+    group: root
+    mode: u=rw,g=r,o=r
+
+- name: Ensure knot-exporter is running and enabled
+  tags: [ auth-dns ]
+  become: true
+  ansible.builtin.systemd:
+    name: knot-exporter.service
+    state: started
+    enabled: true
+    daemon_reload: "{{ deploy_service_file.changed }}"
+
diff --git a/roles/knot/tasks/main.yaml b/roles/knot/tasks/main.yaml
index cdf9511..bdf5cf7 100644
--- a/roles/knot/tasks/main.yaml
+++ b/roles/knot/tasks/main.yaml
@@ -1,3 +1,4 @@
 ---
 - ansible.builtin.import_tasks: 01-install.yaml # noqa: name[missing]
 - ansible.builtin.import_tasks: 02-configure.yaml # noqa: name[missing]
+- ansible.builtin.import_tasks: 03-configure-exporter.yaml # noqa: name[missing]
diff --git a/roles/knot/templates/knot-exporter.service.j2 b/roles/knot/templates/knot-exporter.service.j2
new file mode 100644
index 0000000..1246694
--- /dev/null
+++ b/roles/knot/templates/knot-exporter.service.j2
@@ -0,0 +1,17 @@
+# {{ ansible_managed }}
+[Unit]
+Description=knot prometheus exporter
+Wants=network.target
+Before=alloy.service
+After=network.target
+
+[Service]
+User=knot
+ExecStart=/usr/sbin/knot-exporter
+ReadWritePaths=/run/knot/
+ProtectSystem=strict
+ProtectHome=true
+PrivateTmp=true
+PrivateDevices=true
+PrivateIPC=true
+