Bug 1080837

Summary:	[tracking] [rel-eng] use cases for depsolving
Product:	[Fedora] Fedora	Reporter:	Daniel Mach <dmach>
Component:	hawkey	Assignee:	Packaging Maintenance Team <packaging-team-maint>
Status:	CLOSED CANTFIX	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	22	CC:	jsilhan, jzeleny, packaging-team-maint, rholy
Target Milestone:	---
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-07-22 11:17:51 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	979353, 1049205, 1049209, 1173027, 1225501
Bug Blocks:	578256

Description Daniel Mach 2014-03-26 08:38:52 UTC

rel-eng use cases for depsolving

Depsolving for package installation and for composes is different.
All packages in a compose doesn't have to be installable at once for example.

We need following scenarios supported:


User defined arch for depsolving
--------------------------------
We need to do depsolving for any arch on a single host.
For example ppc64 on x86_64.
We don't install the packages, only use the package list to create repos.


Package conflicts
-----------------
Packages can conflict, but every single package has to be installable.
In other words:
 * install * may not always work
 * install <foo> works
   install <bar> works
   but install <foo> <bar> ends with a conflict


Unresolved dependencies
-----------------------
Composes can contain unresolved dependencies.
We need dnf/hawkey to return a reasonable package set even if all deps weren't met.


Greedy depsolving
-----------------
Install all possible packages providing a reldep.
Example:
 * Requires: MTA
   Installed deps: exim sendmail postfix opensmtpd (all providing MTA)

Comment 1 Ales Kozumplik 2014-03-26 10:29:27 UTC

Discussed this with Dan over IRC. The goal would be to provide this step by step, perhaps using this bugzilla as a tracking bug.

Comment 2 Ales Kozumplik 2014-03-27 13:07:59 UTC

(In reply to Daniel Mach from comment #0)
> Package conflicts
> -----------------
> Packages can conflict, but every single package has to be installable.
> In other words:
>  * install * may not always work
>  * install <foo> works
>    install <bar> works
>    but install <foo> <bar> ends with a conflict

This is already supported by creating one goal for each package and adding packages separately, then solving all the goals.

Comment 3 Ales Kozumplik 2014-03-27 13:10:09 UTC

(In reply to Daniel Mach from comment #0)
> Unresolved dependencies
> -----------------------
> Composes can contain unresolved dependencies.
> We need dnf/hawkey to return a reasonable package set even if all deps
> weren't met.

Dan please specify more, perhaps add an example: what is the input and what is the desired package set on the output? 

It would be best if this was filed as a separate bugzilla.

Comment 4 Ales Kozumplik 2014-03-27 13:11:16 UTC

(In reply to Daniel Mach from comment #0)
> Greedy depsolving
> -----------------
> Install all possible packages providing a reldep.
> Example:
>  * Requires: MTA
>    Installed deps: exim sendmail postfix opensmtpd (all providing MTA)

This is already doable by obtaining all pacakges providing 'MTA' and then filling a goal with them.

Comment 5 Ales Kozumplik 2014-03-27 13:14:04 UTC

(In reply to Daniel Mach from comment #0)
> User defined arch for depsolving
> --------------------------------
> We need to do depsolving for any arch on a single host.
> For example ppc64 on x86_64.
> We don't install the packages, only use the package list to create repos.
> 

This is already doable, e.g. on the x86_64 machine:

   sack = hawkey.Sack(arch='ppc64')

Comment 6 Jaroslav Reznik 2015-03-03 15:38:02 UTC

This bug appears to have been reported against 'rawhide' during the Fedora 22 development cycle.
Changing version to '22'.

More information and reason for this action is here:
https://fedoraproject.org/wiki/Fedora_Program_Management/HouseKeeping/Fedora22

Comment 7 Honza Silhan 2015-07-22 11:17:51 UTC

rel-eng use case is different than regular DNF dependency solving. Now Pungi can run many DNF queries to fit their use case.