Installation order of basesystem, filesystem and setup.

[Phil Knirsch]

Hi folks.

During the review of basesystem we came upon a rather interesting fact 
which some might already have seen and wondered about.

The packages basesystem, filesystem and setup have a rather odd and not 
necessarily intuitive dependency order:

basesystem Requires: filesystem setup
filesystem Requires: setup
setup Requires: (nothing)

So the final install order after properly ordering those is:

setup
filesystem
basesystem

which imo is exactly the opposite of what i'd expect. Take the 
description of basesystem e.g. where it explicitly says:

"Basesystem should be the first package installed on a system, and it
should never be removed."

And for filesystem:

"Filesystem contains the basic directory layout for a Linux operating 
system, including the correct permissions for the directories."

So imo the order should be:

basesystem
filesystem
setup

Currently the way to get basesystem always pulled in (and thereby 
filesystem and setup) is by having a:

glibc Requires: basesystem

Now the question is, do we just keep it this way and ignore the fact 
that those 3 packages are installed in the wrong order (without actually 
affecting anything as they are installed even before glibc) or do we 
want to fix it?

The simple fix would be to turn around the requirement order and let 
glibc require setup instead:

glibc Requires: setup
setup Requires: filesystem
filesystem Requires: basesystem

Any thoughts?

Read ya, Phil

-- 
Philipp Knirsch      | Tel.:  [phone]
Development          | Fax.:  [phone]
Red Hat GmbH         | Email: Phil Knirsch <phil(a)redhat.de&gt;
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D-70178 Stuttgart
Motd:  You're only jealous cos the little penguins are talking to me.

[Jakub Jelinek]

On Fri, Mar 02, 2007 at 04:33:19PM +0100, Phil Knirsch wrote:
>  During the review of basesystem we came upon a rather interesting
> fact 
>  which some might already have seen and wondered about.
>  
>  The packages basesystem, filesystem and setup have a rather odd and not 
>  necessarily intuitive dependency order:
>  
>  basesystem Requires: filesystem setup
>  filesystem Requires: setup
>  setup Requires: (nothing)
>  
>  So the final install order after properly ordering those is:
>  
>  setup
>  filesystem
>  basesystem
>  
>  which imo is exactly the opposite of what i'd expect. Take the 
>  description of basesystem e.g. where it explicitly says:
>  
>  "Basesystem should be the first package installed on a system, and it
>  should never be removed."
>  
>  And for filesystem:
>  
>  "Filesystem contains the basic directory layout for a Linux operating 
>  system, including the correct permissions for the directories."
>  
>  So imo the order should be:
>  
>  basesystem
>  filesystem
>  setup 
Well, basesystem contains no files at all and only contains the requires
for filesystem/setup, so if you remove the requires, the package is
completely useless.

	Jakub

[Jesse Keating]

On Friday 02 March 2007 10:33:19 Phil Knirsch wrote:
>  basesystem Requires: filesystem setup
>  filesystem Requires: setup
>  setup Requires: (nothing)
>
>  So the final install order after properly ordering those is:
>
>  setup
>  filesystem
>  basesystem 
Requires doesn't do much for ordering.  The %post / %pre requires or PreReq: 
do help for ordering.  Since basesystem has no files, there probably isn't 
any need for it to be installed before anything else, it just needs to be in 
the same transaction with the things that require it.

-- 
Jesse Keating
Release Engineer: Fedora

[Michael Schroeder]

On Fri, Mar 02, 2007 at 10:42:44AM -0500, Jesse Keating wrote:
>  Requires doesn't do much for ordering.  The %post / %pre requires
> or PreReq: 
>  do help for ordering. 
Not true, rpm uses requires and prereqs for ordering purposes.

Cheers,
  Michael.

-- 
Michael Schroeder                                   mls(a)suse.de
main(_){while(_=~getchar())putchar(~_-1/(~(_|32)/13*2-11)*13);}

[Jesse Keating]

On Friday 02 March 2007 11:06:27 Michael Schroeder wrote:
>  Not true, rpm uses requires and prereqs for ordering purposes.
Ok, let me clarify.  A plain Requires: doesn't guarantee that the Required 
package will be installed before the package Requiring it.  It just means it 
either needs to be there before hand, or in the same transaction.  Things 
like %post/%pre requires and PreReq help rpm in ordering the transaction to 
make sure the the things that are needed at install time are actually there, 
vs things needed at runtime.

-- 
Jesse Keating
Release Engineer: Fedora

[Michael Schroeder]

On Fri, Mar 02, 2007 at 11:35:46AM -0500, Jesse Keating wrote:
>  Ok, let me clarify.  A plain Requires: doesn't guarantee that the
> Required 
>  package will be installed before the package Requiring it.  It just means it 
>  either needs to be there before hand, or in the same transaction.  Things 
>  like %post/%pre requires and PreReq help rpm in ordering the transaction to 
>  make sure the the things that are needed at install time are actually there, 
>  vs things needed at runtime. 
Well, it's just so that rpm treats PreReqs and Requires pretty much the
same, the only difference is when there is a dependency cycles.
And dependency cycles with PreReqs aren't installable at all, so there
really is no difference...

Cheers,
  Michael.

-- 
Michael Schroeder                                   mls(a)suse.de
main(_){while(_=~getchar())putchar(~_-1/(~(_|32)/13*2-11)*13);}

[Phil Knirsch]

Jesse Keating wrote:
>  On Friday 02 March 2007 11:06:27 Michael Schroeder wrote:
> > Not true, rpm uses requires and prereqs for ordering purposes.
>  
>  Ok, let me clarify.  A plain Requires: doesn't guarantee that the Required 
>  package will be installed before the package Requiring it.  It just means it 
>  either needs to be there before hand, or in the same transaction.  Things 
>  like %post/%pre requires and PreReq help rpm in ordering the transaction to 
>  make sure the the things that are needed at install time are actually there, 
>  vs things needed at runtime.
>  
>   
Well, current rpm code as it is still honors this, Jesse, and i think 
thats what Michael just wanted to point out.

Simple Require chains will get ordered properly today in rpm and should 
in any future version of it too (Although stricktly speak you're of 
course right. Only any pre requires need to be absolutely followed as 
otherwise during installation things will go badly wrong).

I don't wanna beat a dead horse here and i'm certainly not biased to any 
form of proper order we're installing basesystem, filesystem and setup 
here. I was just surprised that the Requires were setup in like this 
between the those packages in that order (as was the package reviewer of 
basesystem) with a description like that in basesystem. I'd wouldn't 
have any problems dropping basesystem and just keeping filesystem and 
setup either. Or just leave it everything as it is.

I just wanted to bring this up during the review of basesystem as both 
my reviewer and myself found it a little wierd that "first package 
installed on a system" actually could never be the first package 
actively installed.

Final option ofc would be to just change the description ofc (doh!) and 
be done with it.

Like:

Basesystem defines the components of a basic Fedora system (for
example, the package installation order to use during bootstrapping).
Basesystem should be in every installation of a system, and it
should never be removed.

How's that?

Read ya, Phil

-- 
Philipp Knirsch      | Tel.:  [phone]
Development          | Fax.:  [phone]
Red Hat GmbH         | Email: Phil Knirsch <phil(a)redhat.de&gt;
Hauptstaetterstr. 58 | Web:   http://www.redhat.de/
D-70178 Stuttgart
Motd:  You're only jealous cos the little penguins are talking to me.

[Bill Nottingham]

Phil Knirsch (pknirsch(a)redhat.com) said: 
>  Final option ofc would be to just change the description ofc (doh!)
> and 
>  be done with it.
>  
>  Like:
>  
>  Basesystem defines the components of a basic Fedora system (for
>  example, the package installation order to use during bootstrapping).
>  Basesystem should be in every installation of a system, and it
>  should never be removed.
>  
>  How's that? 
I like that solution. Don't touch the seven deadly packages!

Bill

[Phil Knirsch]

Bill Nottingham wrote:
>  Phil Knirsch (pknirsch(a)redhat.com) said: 
> > Final option ofc would be to just change the description ofc (doh!) and 
> > be done with it.
> >
> > Like:
> >
> > Basesystem defines the components of a basic Fedora system (for
> > example, the package installation order to use during bootstrapping).
> > Basesystem should be in every installation of a system, and it
> > should never be removed.
> >
> > How's that?
>  
>  I like that solution. Don't touch the seven deadly packages!
>  
>  Bill
>   
Done :)

Read ya, Phil

/me wonders what the other 6 deadly packages are and is afraid. very 
afraid. :)

-- 
Philipp Knirsch      | Tel.:  [phone]
Development          | Fax.:  [phone]
Red Hat GmbH         | Email: Phil Knirsch <phil(a)redhat.de&gt;
Hauptstaetterstr. 58 | Web:   http://www.redhat.de/
D-70178 Stuttgart
Motd:  You're only jealous cos the little penguins are talking to me.

[Enrico Scholz]

pknirsch(a)redhat.com (Phil Knirsch) writes:

>  basesystem Requires: filesystem setup
>  filesystem Requires: setup
>  setup Requires: (nothing)
>
>  So the final install order after properly ordering those is:
>
>  setup
>  filesystem
>  basesystem 
I would expect this order:

1. filesystem (there must be something where files can be stored)
2. setup (stuff like /etc/passwd); this should require the package
   which is shipping /etc and perhaps /usr/share/doc
3. basesystem; requires filesystem + setup

There is a problem with 'filesystem' because it ships files owned by
non-root and requires /etc/passwd therefore.

My suggestion:

* split 'filesystem' into:
  - 'filesystem-base' -> owns '/', '/etc' +
'/usr/share/doc' (and all
    parents); perhaps some toplevel dirs like /var and /bin too
  - 'filesystem' -> owns the other dirs from current 'filesystem'
* keep 'filesystem-base' dependency-less
* add:
  - to 'basesystem'
    | Requires(pre):    setup, filesystem
    | Requires(postun): setup, filesystem
  - to 'setup'
    | Requires(pre):    filesystem-base
    | Requires(postun): filesystem-base

  - to 'filesystem'
    | Requires(pre):    setup, filesystem-base
    | Requires(postun): setup, filesystem-base

  Perhaps the redundant deps can be removed




Enrico