Using Runit on Devuan
If you’re running Devuan and want a minimal, reliable init replacement that doesn’t bring the whole systemd baggage, runit is your go‑to. You’ll learn how to get it installed, set up services, and keep them alive even when something goes wrong.
Step 1: Install Runit
sudo apt-get update && sudo apt-get install runit
Devuan’s package manager ships a clean, battle‑tested build of runit. It pulls in just the runtime and supervisor; no extra dependencies that could bloat your system.
Step 2: Prepare the Service Directory
Create a directory for your service under /etc/sv. For example, to keep nginx running:
sudo mkdir -p /etc/sv/nginx/run
Inside run, add an executable script that starts and restarts your program. A simple version for nginx looks like this:
#!/bin/sh
exec start-stop-daemon --start --quiet --background --pidfile /var/run/nginx.pid \
--exec /usr/sbin/nginx -- -c /etc/nginx/nginx.conf
Make it executable:
sudo chmod +x /etc/sv/nginx/run
Runit expects a run script that stays in the foreground. The start-stop-daemon trick keeps nginx running as a background process while still allowing runit to monitor its PID.
Step 3: Enable the Service
sudo ln -s /etc/sv/nginx /var/service
That symlink tells runit to supervise /etc/sv/nginx. Runit watches /var/service for any linked directories and starts them automatically during boot.
Step 4: Test the Setup
sudo sv start nginx # or just sv restart nginx
Check status:
sudo sv status nginx
You should see “alive” in green. If you kill the process, runit will immediately respawn it.
Common Pitfalls (and How I Learned Them)
I once tried to run a custom script that logged to /var/log/custom.log but forgot to make the log file writable by the service’s user. Runit kept restarting it in an endless loop, and my console filled with “permission denied” errors. The fix? Add --chuid to the start-stop-daemon command or simply give the directory proper permissions before starting.
Another hiccup: some people try to use systemd‑style unit files with runit. That never works because runit doesn’t read them. Stick to the simple run script, and you’re good.
Advanced: Using Runit for Multiple Services
If you have several services—say Docker, a MySQL instance, and a custom API—you can mirror the steps above for each:
sudo mkdir -p /etc/sv/docker/run # add docker start script... sudo ln -s /etc/sv/docker /var/service sudo mkdir -p /etc/sv/mysql/run # add mysql start script... sudo ln -s /etc/sv/mysql /var/service
Runit will keep all of them alive, restart on crash, and report status in /var/log/runit. No need for a heavy process manager.
When Runit Might Not Be Enough
If you rely heavily on socket activation or want deep integration with network interfaces, runit’s simplicity can feel limiting. In those cases, consider OpenRC or s6, which offer more hooks. But for most everyday services—web servers, SSH, cron—runit is lean and rock‑solid.
Hope that helps you keep your Devuan box humming without the bloat of systemd.
