Request: Autoconnect avahi-observe plug for lxi-tools

lundmar 2017-11-28 20:02:14 UTC #1

Hi,

I would like to request that the lxi-tools snap gets automatically connected to the ‘avahi-observe’ plug interface.

lxi-tools uses the avahi-daemon strictly as a client to discover various LXI instruments on the network.

However, this currently fails on e.g. Ubuntu because of its stricter security mechanisms (apparmor etc.) and I would like to avoid the users having to do stuff like this:

snap connect lxi-tools:avahi-observe :avahi-observe

Here is the lxi-tools snapcraft configuration:

github.com

lxi-tools/lxi-tools.snapcraft/blob/master/snap/snapcraft.yaml

name: lxi-tools
version: '1.16'
summary: Open source LXI tools
description: |
  Lxi-tools is a collection of open source software tools that enables control
  of LXI compatible instruments such as modern oscilloscopes, power supplies,
  spectrum analyzers etc.

grade: stable
confinement: strict
icon: snap/icon/lxi-tools_256x256.png

apps:
  lxi:
    command: bin/lxi
    completer: share/bash-completion/completions/lxi
    plugs: [home, network, avahi-observe]
    aliases: [lxi]

parts:

This file has been truncated. show original

Thanks.

lundmar 2017-12-04 21:48:15 UTC #2

Looking for response on this request. Thanks.

jdstrand 2017-12-04 22:19:21 UTC #3

I don’t have a lot of familiarity with LXI, but I can see that http://lxistandard.org/ mentions that a core part of the functionality is reaching other LXI enabled instruments. While part of me feels like the manual connection would be ok (at least once gnome-software supports interface connections graphically), the instrument discovery via avahi seems such a core piece of its usage that avahi-observe auto-connection is appropriate. It’s too bad avahi-daemon doesn’t already have fine-grained controls so we could grant service discovery to something like _lxi.tcp (or similar), but that isn’t available at this time.

While avahi-observe leaks more than is strictly required for lxi-tools, +1 for auto-connection based on the above.

lundmar 2017-12-04 22:41:11 UTC #4

Exactly right.

Just for future reference - the lxi tool does service discovery of the following services:

_lxi._tcp
_vxi-11._tcp
_scpi-raw._tcp
_scpi-telnet._tcp

lundmar 2017-12-05 13:29:17 UTC #5

One more vote needed? Thanks.

zyga 2017-12-05 19:00:14 UTC #6

I formally give my +1; I’d love to try this with my LXI-enabled equipment.

kyrofa 2017-12-05 19:19:07 UTC #7

Agreed. Reading up on liblxi and lxi-tools, it sounds like every user will need to connect this in order for it to be useful. On that front, +1 to autoconnection.

However, note that this interface is not provided by the core snap on Ubuntu Core. Are we also granting autoconnection to the avahi snap?

jdstrand 2017-12-05 19:21:11 UTC #8

The snap declaration would allow that, yes.

jdstrand 2017-12-05 19:23:12 UTC #9

2 votes (from reviewers) for, 0 against. Granting auto-connection. This is now live.