a networking service snap like xkcd doesn't wait for the server to be listening

[Leo Arias]

I think that installing a service that listens on a port should return until the server is ready listening on that port.
For example, on snappy install xkcd-webserver, after the command finishes we should be able to access the webserver immediately.

According to http://www.freedesktop.org/software/systemd/man/systemd.service.html#Type= the default service type will wait until the service is running. In this xkcd example, systemctl start waits for the service to be running, which means that the main is being executed. But there's still some time between running main and starting the listener on port 80.

Then, if we put in a script a install followed by a get it will fail. We need to add a sleep or poll until the server is running.

IMO, the systemd service file for a network service should wait until the server has been fully started.

[Michael Vogt (mvo)]

This is still the case in Ubuntu Core 16:
$ sudo snap remove xkcd-webserver ; sudo snap install xkcd-webserver ; printf "GET / HTTP/1.0\n\n" |nc -v localhost 80
xkcd-webserver removed
xkcd-webserver (stable) 16.04-6 from 'canonical' installed
nc: connect to localhost port 80 (tcp) failed: Connection refused
nc: connect to localhost port 80 (tcp) failed: Connection refused

[Zygmunt Krynicki (zyga)]

We removed the "port" feature so I'm marking this as won't fix.