pbuilder-apt-config

[Loïc Minier]

On Sun, Jan 31, 2010, Osamu Aoki wrote:
> I think one important factor is the separation of data from code.

 Did you see the new --mirror-map flag?  It allows point to a file which
 has:

    debian              http://ftp.de.debian.org/debian/
    ubuntu              http://archive.ubuntu.com/ubuntu/

> I wonder why you did not start with the following (This patch is against
> sligtly old source but enough to identify what I am talking):
> -------------
> @@ -81,13 +81,13 @@ builtin_mirror_map() {
>  
>      case "$archive" in
>        backports.org)
> -        echo "http://www.backports.org/backports.org/"
> +        echo "$mirror_backports"
>        ;;
>        debian)

 These are the builtin defaults; they only get used if the archive isn't
 found in the mirror map.  ("builtin_mirror_map()")

 I started with builtin URLs because that made testing + development
 easier to start with, then looked for a form of override better than
 --mirror, and this is how I came with --mirror-map.  I can still add
 other options to set mirror, for instance we could change --mirror to
 handle archive + URL e.g.:
    --mirror "backports http://www.backports.org/backports.org/"

> +mirror_backports="http://www.backports.org/backports.org/"
> +mirror_debian="http://ftp.us.debian.org/debian/"
> +mirror_debian_archive="http://archive.debian.org/debian/"
> +mirror_ppa="http://ppa.launchpad.net"
> +mirror_ubuntu="http://archive.ubuntu.com/ubuntu/"
> +mirror_ubuntu_ports="http://ports.ubuntu.com/ubuntu-ports/"
> +mirror_debian_security="http://security.debian.org/"
> +mirror_debian_volatile="http://volatile.debian.org/debian-volatile/"

 Sure, that could work too, but that's *less* data driven IMO since you
 have to encode each archive in a shell var.  Currently, the only
 archive specific shell vars are in the --profile code which is meant to
 be archive-specific.

 Also, I find it less convenient to pass a lot of --mirror-something
 flags or to set a bunch of FOO_MIRROR= vars: mirrors typically don't
 change for your various pbuilder environments.  The Ubuntu archive is
 always going to be at http://mirror/ubuntu/ for me, and at
 http://archive.ubuntu.com/ubuntu/ for people who don't have a mirror;
 even if I have 10 profiles using this archive (or not).

> -------------
> * overriding from coimmand line:
>   we can have command line option to set each value if we wish.

 Ack, I only offer --mirror-map; I felt that was the most natural for
 data which doesn't change; my intent is to install a default map in
 /etc/pbuilder/mirrors.pbuilderrc (or something like that) and have
 pbuilder always pass it.

 It's true that for the standalone tool, it's harder to override a
 single archive mirror without creating a file.  Would you find
 --mirror="archive-name archive-url" sufficiently usable?
   I could also make it --mirror-somarchive=url or
 --somearchive-mirror=url, but that would probably mean moving away of
 "getopt"; also, I would prefer avoiding the archive name in the flag
 name because of archives such as ppa:someone or backports.org
 (--mirror-backports.org=url or --ppa:someone-mirror=url is not very
 elegant and is hard to parse right).

> * overriding via environment variable:
>   use mirror_ubuntu_ports="${mirror_ubuntu_ports:+http://ports.ubuntu.com/ubuntu-ports/} instead.

 For the same reason as for flags, it would be a bit hard to map these
 to vars; e.g. to set the URL of the mirror of backports.org or
 ppa:foobar.  I could change the archive names, but I'm keen to keep a
 mapping with archive names from the mirror lists.

> * override via configuration file:
>   source something like /usr/share/pbuilder/archives and optionally
>   /etc/pbuilder/archives to set these variables.

 Yup; that's definitely supported

> >  I'm currently thinking we should rip away the MIRROR debconf stuff
> >  entirely and just default to autoguessing depending on the target of
> >  the package and of the current distro.
> 
> That is one way but I think we can keep it as long as we let it set
> something like $debian_mirror or $ubuntu_mirror using some guessing from
> URL.

 Well I see debconf as a frontend to what's in /etc/pbuilderrc; if we
 drop it, only new users should suffer from it, but old users will keep
 MIRROR in their /etc/pbuilderrc.  I have no idea what to map the
 historic data to, except to pbuilder-apt-config --mirror (for --suite
 mode).

 We could write some Debconf frontend to set *any* mirror, but I think
 that's quite hard.

-- 
Loïc Minier