adds mysql exporter. Installs on database host

host_vars/database.yml

@@ -5,5 +5,5 @@ custom_firewall_ports:
   - 3306
 apt_packages:
   - nfs-kernel-server
-# install_mysql_exporter: true
+install_mysqld_exporter: true
 description: 'database & filestorage node for hosting app.retailor.io'

plays/metrics-node.yml

@@ -6,12 +6,16 @@
     nginx_exporter_version: "1.4.1"
     cadvisor_version: "0.46.0"
     fail2ban_exporter_version: "0.10.2"
+    mysqld_exporter_version: "0.17.2"
   roles:
-    - role: roles/node_exporter
-    - role: roles/fail2ban_exporter
-    - role: roles/redis_exporter
+    - role: roles/exporter-node
+    - role: roles/exporter-fail2ban
+
+    - role: roles/exporter-redis
       when: install_redis_exporter
-    - role: roles/cadvisor
+
+    - role: roles/exporter-cadvisor
       when: install_cadvisor_exporter
-    - role: roles/nginx_prometheus_exporter
-      when: install_nginx_exporter
+
+    - role: roles/exporter-mysql
+      when: install_mysqld_exporter

roles/exporter-mysql/README.md

@@ -0,0 +1,11 @@
+# mysqld exporter
+
+(https://github.com/prometheus/mysqld_exporter)[https://github.com/prometheus/mysqld_exporter]
+
+## Required Grants
+
+```mysql
+CREATE USER 'exporter'@'localhost' IDENTIFIED BY 'XXXXXXXX' WITH MAX_USER_CONNECTIONS 3;
+GRANT PROCESS, REPLICATION CLIENT, SELECT ON *.* TO 'exporter'@'localhost';
+```
+

roles/exporter-mysql/tasks/install.yml

@@ -0,0 +1,23 @@
+---
+- name: Download MySQL Prometheus Exporter
+  get_url:
+    url: "https://github.com/prometheus/mysqld_exporter/releases/download/v{{ mysqld_exporter_version }}/mysqld_exporter-{{ mysqld_exporter_version }}.linux-amd64.tar.gz"
+    dest: "/tmp/mysqld-exporter.tar.gz"
+
+- name: Extract MySQL Prometheus Exporter
+  unarchive:
+    src: "/tmp/mysqld-exporter.tar.gz"
+    dest: "/tmp"
+    remote_src: yes
+
+- name: copy my.cnf config
+  template:
+    src: "my.cnf.j2"
+    dest: "/root/my.cnf.j2"
+
+- name: Move MySQL Prometheus Exporter binary
+  copy:
+    src: "/tmp/mysqld_exporter-{{ mysqld_exporter_version }}.linux-amd64/mysqld_exporter"
+    dest: "/usr/local/bin/mysqld_exporter"
+    remote_src: yes
+    mode: '0755'

roles/exporter-mysql/tasks/main.yml

@@ -0,0 +1,6 @@
+---
+# ensure we have variables from .env files
+- include_tasks: ../roles/env/tasks/main.yml
+
+- include_tasks: install.yml
+- include_tasks: service.yml

roles/exporter-mysql/tasks/service.yml

@@ -0,0 +1,23 @@
+---
+- name: Create mysqld_exporter service file
+  template:
+    src: "mysqld_exporter.service.j2"
+    dest: "/etc/systemd/system/mysqld_exporter.service"
+    mode: '0644'
+  tags:
+    - create_service
+
+- name: Reload systemd to pick up the mysqld_exporter service
+  systemd:
+    daemon_reload: yes
+  tags:
+    - reload_systemd
+
+- name: Enable and start the mysqld_exporter service
+  systemd:
+    name: mysqld_exporter
+    state: started
+    enabled: yes
+  tags:
+    - start_mysqld_exporter
+

roles/exporter-mysql/templates/my.cnf.j2

@@ -0,0 +1,3 @@
+[client]
+user = {{ env_vars.DB_USERNAME }}
+password = {{ env_vars.DB_PASSWORD }}

roles/exporter-mysql/templates/mysqld_exporter.service.j2

@@ -0,0 +1,12 @@
+[Unit]
+Description=mysqld exporter
+After=network.target
+
+[Service]
+User=nobody
+ExecStart=/usr/local/bin/mysqld_exporter --config.my-cnf=/home/forge/.my.cnf
+Restart=always
+
+[Install]
+WantedBy=multi-user.target
+