Request: CUPS Snap (“cups”) auto connection to of cups:cups-control to cups:admin and also of the network-manager-observe interface

store-requests
31

@jamesh, @reviewers:

I got it working now:

First I re-defined plugs and slots in snapcraft.yaml:

plugs:
  cups-internal:
    interface: cups-control

slots:
  # Provide the cups-control and cups slots for other snaps to connect to
  cups-control:
    interface: cups-control
  cups:
    interface: cups

I set the slots of cupsd as follows:

apps:
  cupsd:
    [...]
    slots: [cups-control, cups]

On all other apps I replaced the plugs cups and cups-control by cups-internal:

  cups-browsed:
    [...]
    plugs: [network, network-bind, network-manager-observe, avahi-control, cups-internal]
  lpinfo:
    command: sbin/lpinfo
    plugs: [network, cups-internal]
  lpadmin:
    command: sbin/lpadmin
    plugs: [network, avahi-control, home, cups-internal]
  lpstat:
    command: bin/lpstat
    plugs: [network, avahi-control, cups-internal]
  [...]

I build CUPS with a configure option to call the cupsctl API call with cups-control as slot name:

parts:
  [...]
  cups:
    [...]
    configflags:
      [...]
      - --with-cups-control-slot=cups-control
      [...]

Now I change the connection I requested in this thread to

sudo snap connect cups:cups-internal cups:cups-control
sudo snap connect cups:network-manager-observe

and for external utilities (example) I do the following connections:

sudo snap connect cups-admin-test:cups-control cups:cups-control
sudo snap connect cups-user-app-test:cups cups:cups

Now it all works as expected.

@reviewers:

This means:

This request should be now considered as that following auto-connections are requested:

sudo snap connect cups:cups-internal cups:cups-control
sudo snap connect cups:network-manager-observe

The auto-connections are internally doing the same as the original ones, the interfaces are only renamed.

It must be assured that a Snap of a user application which prints and is put into the Snap Store should auto-connect its cups plug to BOTH :cups AND cups:cups on installation. slots-per-plug: * should be used at the right place for that.

Same for Snaps of printer managers using cups-control with the difference that here explicit permission should be needed for auto-connection. Also here slots-per-plug: * at the right place should be used.

@reviewers: I will commit my above-mentioned changes now, could you apply the changes as I described here? Thanks in advance.