Comment 1 for bug 1702332

Ideally this should be handled directly by MaaS, or disable the unrelated services (such as snapd).

I worked around the problem with a custom script.

cat > 0-maas-http_proxy << EOF
#! /bin/bash

echo 'http_proxy=http://myproxy.example.com:8080' >> /etc/environment
echo 'https_proxy=http://myproxy.example.com:8080' >> /etc/environment
EOF

... and upload it as graphic interface under Settings > "Commissioning scripts".

If you also need to deal with the calls to ntp.ubuntu.com (bug #1702329), append something like this to the script above.

sed -i 's/^#NTP=/NTP=ntp.example.com/' /etc/systemd/timesyncd.conf
service systemd-timesyncd restart