You will need at least snapd 2.30 on your device and access to a registered Snap Store Proxy.
To configure snapd on a device to talk to the proxy, you need to
ack the signed assertion that allows snapd to trust the proxy, e.g.:
curl -s http://<domain>/v2/auth/store/assertions | sudo snap ack /dev/stdin
Once snapd knows about the store assertion, you then have to configure it to use the proxy:
sudo snap set core proxy.store=STORE_ID
You can retrieve the
STORE_ID using the status command on the Proxy server:
If you want to later disconnect a device from the proxy:
sudo snap set core proxy.store=''
Note that the next time the device refreshes, it will get the upstream snap revisions (any overrides won't be in effect).
With devices connected to the proxy, you can create overrides to control snap updates on them.