如何重新加载nginx配置（如果正在运行）或启动（如果已停止）？

Question

I update nginx config files periodically and due to technical issues sometimes it can happen that nginx is not running.

In this case if I run nginx -s reload , I see this error:

nginx: [error] open() "/run/nginx.pid" failed (2: No such file or directory)

How can I reload nginx config with the command from above if it's running or start if it's not running without seeing that error?

Answer 1

If you can't count on the fact that nginx is already running then you should just restart it. But, if you really want the above, assuming you're running on linux/unix and it looks like you are then you can create a tiny shell script. Again, assuming your default shell is bash or bash compatible (other shells would have to be ported) you could do something like this:

#!/bin/sh

if [ -f /run/nginx.pid ]; then
   /path/to/nginx -s reload
else
   /path/to/whatever/command/starts/nginx
fi

You can take the above to a whole new level by using inotify. Again, assuming you're running a Linux distribution, you can install your OS distribution's inotify-tools package and automate running the above script file every time your config files change. See this for more info on using inotify:

How to execute a command when a file changes