Service need to be restarted after account-control interface is connected

dmh · August 19, 2019, 7:49am

Hello,

I use PAM to authenticate users in a web service in the snap. This use case requires the account-control interface.
The account-control interface is not auto connected. Normally after snap installed, the web server started before the account-control interface was connected.
It seems that the permissions were not granted to web service immediately after account-control is connected. Restart of web server is needed.

Then I use hook connect –plug-account-control to restart the web service automatically. It works.

Just out of curious, Is that how it was designed? After interfaces connected, the service need to be restarted?

Thanks

ogra · August 20, 2019, 11:39am

if you use some wrapper script for your webserver, you can make it wait until the ressource you want to access is available … here is an example …

github.com

ogra1/timezone-snap/blob/master/geoip.sh

#! /bin/sh

set -e

TZ="$(wget -q -O- https://geoip.ubuntu.com/lookup|sed 's/^.*<TimeZone>//;s/<\/.*$//')"

[ -n "$TZ" ] || exit 0

while ! timedatectl set-timezone "$TZ"; do
    echo "timezone control interface not connected yet, please run:"
    echo "snap connect $SNAP_NAME:timezone-control"
    echo "sleeping for 10 sec"
    sleep 10
done

kyrofa · August 20, 2019, 3:48pm

Instead of wrapping your service in a script, you can also implement an interface hook that runs when that interface is connected. Within that hook, you can make sure your service is restarted with snapctl restart <snapname>.<servicename>.

ogra · August 20, 2019, 4:51pm

ah, yeah, sorry, that snap above pre-dates the existence of interface-hooks

dmh · August 21, 2019, 2:44pm

@ogra @kyrofa Thank you guys. I tried the interface hook for restarting service and it works