Re: Recommended way to manually add an undiscovered IPP printer in CUPS 3.x

Till,

> On Aug 1, 2026, at 5:21=E2=80=AFPM, Till Kamppeter =
<[email protected]> wrote:
>=20
> On 8/1/26 22:41, Michael Sweet wrote:
>> Till,
>>> On Aug 1, 2026, at 3:50=E2=80=AFPM, Till Kamppeter =
<[email protected]> wrote:
>>> ...
>>> But how to proceed under CUPS 3.x?
>> CUPS 3.x uses PAPPL 2.x which has different operations and attribute =
names (as part of standardization in the PWG) but otherwise works =
similarly.
>> The Create-Printer operation accepts the "smi55357-device-uri (uri)" =
and "smi55357-driver (keyword)" operation attributes to provide the =
device URI and model/driver name, and cupslocald (from the cups-local =
project) supports the following driver names:
>> - 'everywhere': IPP Everywhere/AirPrint/Mopria/Wi-Fi Direct printer
>> - 'pcl': Generic B&W PCL printer
>> - 'pcl_duplex': Generic B&W PCL printer with 2-sided printing support
>> - 'ps': Generic B&W PostScript printer
>> - 'ps_duplex': Generic B&W PostScript printer with 2-sided printing =
support
>> - 'ps_color': Generic Color PostScript printer
>> - 'ps_color_duplex': Generic Color PostScript printer with 2-sided =
printing support
>> The PCL and PostScript drivers are extremely limited and are just =
there to support legacy Samba printing basic support for local =
(typically enterprise) laser printers.
>=20
> So when I send a Create-Printer request to a CUPS 3.x daemon (both =
local and sharing) an entry in a profile (~/.cups/profiles/ or =
/etc/cups/profiles/*, latter only for sharing server) is created?

*No*.

Profiles are ONLY for the local server, and they are manually created by =
the user/admin.  Profiles in /etc/cups/profiles (or similar "world" =
directories apply to all users while profiles under $HOME apply to that =
user.  There is one cupslocald running per logged-in user on a system.

The goal is that cupslocald will only list those printers/servers that =
it can connect to, and will periodically update the list of available =
printers as conditions change (switching networks, printers/servers =
coming and going, etc.)

>>> If I have only the local server, it is stateless, it only uses =
temporary queues.
>> It is not stateless.  It just doesn't have permanent queues and =
doesn't share local queues with other systems.
>>> How do I, in case of not using mDNS/DNS-SD, tell my =
discoveries/manual IP selections to the local server so that it sticks =
with them? Or am I REQUIRED to use mDNS/DNS-SD when I have a system with =
only the local server of CUPS 3.x as print environment?
>> We have been talking about this ("printer profiles") for a very long =
time:
>>     https://github.com/OpenPrinting/cups-local/issues/2
>=20
> OK, so they also work with the local server.

They *only* work with the local server.  The sharing server does NOT use =
profiles at all.

> So this means that our printer setup tool which Abdelrahman is working =
on creates entries in the profile when manually adding print =
destinations, either if mDNS/DNS-SD is not used or when the printer is =
outside the local network (VLAN or so)?

No, he should focus on adding printers to the sharing server.  Profiles =
are not intended as things that are created/edited with special tools, =
they are simple text files that replace DNS-SD discovery of IPP =
printers/servers.

> OK, so we need to settle on a format for this file so that Abdelrahman =
can implement that.

The proposed format is in the issue.

>>> Or do I have to use the sharing server when I just want to print =
locally but not use mDNS/DNS-SD? Does the sharing server has a config =
file for holding such printers?
>> The sharing server is more of a traditional "all queues are =
permanent" service and saves the queue state/configuration across runs.
>>=20
>=20
> Does the sharing server not get its queues the same way as the local =
one, both by discovering printers via mDNS/DNS-SD AND including =
destinations by entries in the profile (which can be system-wide now)? =
And it adds rules for how to share these printers also in the profile?

No, the sharing server is more akin to a regular printer application - =
yes, printers get discovered via standard means (DNS-SD, SNMP, USB, =
etc.) and you add the queues (discovered or manual entry) that you want =
to share.  Profiles are NOT used to configure the sharing server, =
although you might use a profile on a client system to point cupslocald =
at a sharing server.

________________________
Michael Sweet