Fix missing Zabbix agent log dir

Logs are stored on a tmpfs to limit writes to storage. Logs are persisted through Graylog anyway. But seems Zabbix agent isn't recreating its log dir if it's missing. This fix ensures the logging directory is created on boot.

README.md

@@ -142,7 +142,7 @@ sudo systemctl enable --now sunrise-alarm
 
 # Run Ansible
 cd deployment
-LC_ALL=C.UTF-8 ansible-galaxy collection install -r requirements.yml
+LC_ALL=C.UTF-8 ansible-galaxy collection install --force -r requirements.yml
 LC_ALL=C.UTF-8 ansible-playbook main.yml
 
 # Reboot

deployment/ensure-var-log-zabbix-exists.service

@@ -0,0 +1,9 @@
+[Unit]
+Description=Ensure /var/log/zabbix exists
+After=var-log.mount
+Requires=var-log.mount
+
+[Service]
+Type=oneshot
+ExecStartPre=/usr/bin/mkdir -p /var/log/zabbix
+ExecStart=/usr/bin/chown zabbix:zabbix /var/log/zabbix

deployment/zabbix-agent.yml

@@ -12,6 +12,37 @@
         name: zabbix-agent2
         state: present
 
+    - name: Setup ensure-var-log-zabbix-exists.service
+      register: setup_log_dir
+      ansible.builtin.copy:
+        src: ensure-var-log-zabbix-exists.service
+        dest: /etc/systemd/system/ensure-var-log-zabbix-exists.service
+        owner: root
+        group: root
+        mode: "644"
+
+    - name: Setup zabbix-agent2 drop-in folder
+      ansible.builtin.file:
+        path: /etc/systemd/system/zabbix-agent2.service.d/
+        state: directory
+        owner: root
+        group: root
+        mode: "755"
+
+    - name: Setup zabbix-agent2 drop-in
+      register: zabbix_agent2_dropin
+      ansible.builtin.copy:
+        src: zabbix-agent2_dropin.service
+        dest: /etc/systemd/system/zabbix-agent2.service.d/ensure-log-dir-exists.conf
+        owner: root
+        group: root
+        mode: "644"
+
+    - name: Reload systemd daemon
+      when: setup_log_dir.changed or zabbix_agent2_dropin.changed
+      ansible.builtin.systemd:
+        daemon_reload: true
+
     - name: Zabbix agent - Update config
       register: zabbix_agent_config
       ansible.builtin.lineinfile:

deployment/zabbix-agent2_dropin.service

@@ -0,0 +1,3 @@
+[Unit]
+After=ensure-var-log-zabbix-exists.service
+Requires=ensure-var-log-zabbix-exists.service