MajorLinux
6592eb4fea
- Fixed 4 broken markdown links (bad relative paths in See Also sections) - Corrected n8n port binding to 127.0.0.1:5678 (matches actual deployment) - Updated SnapRAID article with actual majorhome paths (/majorRAID, disk1-3) - Converted 67 Obsidian wikilinks to relative markdown links or plain text - Added YAML frontmatter to 35 articles missing it entirely - Completed frontmatter on 8 articles with missing fields Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
151 lines
4.3 KiB
Markdown
151 lines
4.3 KiB
Markdown
---
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title: "Managing Linux Services: systemd and Ansible"
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domain: linux
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category: process-management
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tags: [systemd, ansible, services, linux, automation]
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status: published
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created: 2026-03-08
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updated: 2026-03-08
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---
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# Managing Linux Services: systemd and Ansible
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If you're running services on a Linux server, systemd is what you're working with day-to-day — starting, stopping, restarting, and checking on things. For managing services across multiple machines, Ansible is where I've landed. It handles the repetitive stuff so you can focus on what actually matters.
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## The Short Answer
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```bash
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# Check a service status
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systemctl status servicename
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# Start / stop / restart
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sudo systemctl start servicename
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sudo systemctl stop servicename
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sudo systemctl restart servicename
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# Enable at boot
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sudo systemctl enable servicename
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# Disable at boot
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sudo systemctl disable servicename
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# Reload config without full restart (if supported)
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sudo systemctl reload servicename
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```
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## systemd Basics
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systemd is the init system on basically every major Linux distro now. Love it or not, it's what you're using. The `systemctl` command is your interface to it.
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**Checking what's running:**
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```bash
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# List all active services
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systemctl list-units --type=service --state=active
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# List failed services (run this when something breaks)
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systemctl list-units --type=service --state=failed
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```
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**Reading logs for a service:**
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```bash
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# Last 50 lines
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journalctl -u servicename -n 50
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# Follow live (like tail -f)
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journalctl -u servicename -f
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# Since last boot
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journalctl -u servicename -b
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```
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`journalctl` is your friend. When a service fails, go here before you do anything else.
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**Writing a simple service file:**
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Drop a `.service` file in `/etc/systemd/system/` and systemd will pick it up.
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```ini
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[Unit]
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Description=My Custom App
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After=network.target
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[Service]
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Type=simple
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User=myuser
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WorkingDirectory=/opt/myapp
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ExecStart=/opt/myapp/start.sh
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Restart=on-failure
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RestartSec=5s
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[Install]
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WantedBy=multi-user.target
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```
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After creating or editing a service file, reload the daemon before doing anything else:
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```bash
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sudo systemctl daemon-reload
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sudo systemctl enable --now myapp
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```
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## Ansible for Service Management Across Machines
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For a single box, `systemctl` is fine. Once you've got two or more servers doing similar things, Ansible starts paying for itself fast. I've been using it heavily at work and it's changed how I think about managing infrastructure.
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The `ansible.builtin.service` module handles start/stop/enable/disable:
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```yaml
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- name: Ensure nginx is started and enabled
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ansible.builtin.service:
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name: nginx
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state: started
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enabled: true
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```
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A more complete playbook pattern:
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```yaml
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---
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- name: Manage web services
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hosts: webservers
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become: true
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tasks:
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- name: Install nginx
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ansible.builtin.package:
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name: nginx
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state: present
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- name: Start and enable nginx
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ansible.builtin.service:
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name: nginx
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state: started
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enabled: true
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- name: Reload nginx after config change
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ansible.builtin.service:
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name: nginx
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state: reloaded
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```
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Run it with:
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```bash
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ansible-playbook -i inventory.ini manage-services.yml
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```
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## Gotchas & Notes
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- **daemon-reload is mandatory after editing service files.** Forgetting this is the most common reason changes don't take effect.
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- **`restart` vs `reload`:** `restart` kills and relaunches the process. `reload` sends SIGHUP and asks the service to re-read its config without dropping connections — only works if the service supports it. nginx and most web servers do. Not everything does.
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- **Ansible's `restarted` vs `reloaded` state:** Same distinction applies. Use `reloaded` in Ansible handlers when you're pushing config changes to a running service.
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- **Checking if a service is masked:** A masked service can't be started at all. `systemctl status servicename` will tell you. Unmask with `sudo systemctl unmask servicename`.
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- **On Fedora/RHEL:** SELinux can block a custom service from running even if systemd says it started fine. If you see permission errors in `journalctl`, check `ausearch -m avc` for SELinux denials.
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## See Also
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- [wsl2-instance-migration-fedora43](../distro-specific/wsl2-instance-migration-fedora43.md)
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- [tuning-netdata-web-log-alerts](../../02-selfhosting/monitoring/tuning-netdata-web-log-alerts.md)
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