How do I get my Golang web server to run in the background?
I have recently completed the Wiki web development tutorial (http://golang.org/doc/articles/wiki/). I had tons of fun and I would like to experiment more with the net/http package.
However, I noticed that when I run the wiki from a console, the wiki takes over the console. If I close the console terminal or stop the process with CTRL+Z then the server stops.
How can I get the server to run in the background? I think the term for that is running in a daemon.
I'm running this on Ubuntu 12.04. Thanks for any help.
Answer
Simple / Usable things first
If you want a start script without much effort, you could use the upstart service. See the corresponding manual page and /etc/init/*.conf for examples. After creating such a process
you can start your server by calling
service myserver start
If you want more features, like specific limitations or permission management, you could try xinetd.
Using the shell
You could start your process like this:
nohup ./myexecutable &
The & tells the shell to start the command in the background, keeping it in the job list.
On some shells, the job is killed if the parent shell exits using the HANGUP signal.
To prevent this, you can launch your command using the nohup command, which discards the HANGUP signal.
However, this does not work, if the called process reconnects the HANGUP signal.
To be really sure, you need to remove the process from the shell's joblist. For two well known shells this can be achieved as follows:
bash:
./myexecutable &
disown <pid>
zsh:
./myexecutable &!
Killing your background job
Normally, the shell prints the PID of the process, which then can be killed using the kill command, to stop the server. If your shell does not print the PID, you can get it using
echo $!
directly after execution. This prints the PID of the forked process.