Allow users to upgrade Ubuntu releases without necessarily being able to contact http://changelogs.ubuntu.com/. In many environments (offline / firewalled / restricted) that isn't possible, but local mirrors may be available nonetheless.

Release Note



At the moment, an Ubuntu system can only be (release) upgraded by using apt (advanced user) or the upgrade-manager (GUI / CLI). The upgrade-manager depends on a file hosted on changelogs.ubuntu.com called meta-release, to determine whether an upgrade is possible and locate the upgrade tool tarball.

This blueprint proposes that these files get moved onto normal mirrors so that a disconnected system with a complete mirror available (quite common in the developing world and corporate environments) can upgrade in a user-friendly manner.

tumbleweed's story

Sorry, I couldn't be at UDS so here's why I called this:

My University has a nasty firewall and forces all port 80 to go via an NTLM-authenticating proxy, so we have to use hacks like cntlm and transparent proxying + cntlm + University proxies, etc.

This is (unfortunately) not an unusual situation in the corporate world. It's just a pity my university is so closed-minded, and I'll be getting out of there ASAP.

Many users with poor connectivity at home, mirror to a big hard drive at work and take thier mirror home.

This is all very nice for an advanced user like me, but we have a fair number of !poweruser Ubuntu users on campus. They complain that they can't upgrade their machines, even though we have a local mirror.

Things we do mitigate this:

  1. We mirror (and mangle) the meta-release files from changelogs.ubuntu.com, and tell users to configure their machines to use them. This is non-optimal.

  2. Our mirror has a virtualhost for changelogs.ubuntu.com so that users can do http_proxy=http://our.mirror/ update-manager Also non-optimal.

  3. Similar hacks for flashplugin and core fonts.

User stories

  • Walter is a user on a Local Only DSL Account. He has access to the national Ubuntu mirrors, but not Canonical in the UK. He can only upgrade with a CD or aptitude.

  • Thembi is a student at University where http access is firewalled and all students are required to use an NTLM proxy for web access. There is a really fast local mirror, but she can only upgrade with a CD or aptitude as update-manager can't connect to http://changelogs.ubuntu.com/.

  • Joe is at a big corporation with heavy firewall rules. As above...


There are many situations where users can access a mirror, but not http://changelogs.ubuntu.com/ and where access to the mirror is more reliable.


Can we move meta-release et al. to the mirrors? What would this require?

Can those meta-release files point at the download tool without an absolute URL? (i.e. it can be grabbed from the current mirror)

I suppose update-manager would possibly need to poke archive.ubuntu.com too, if we don't trust the mirror to be up to date?


Test/Demo Plan

This can be tested with update-managers development update mode (-d), before the next Ubuntu version releases.

Unresolved issues

Other concerns

flashplugin and corefonts break offline upgrades. tumbleweed will see what can be done here.


  • Add a preseedable proxy setting to flashplugin
  • Central config file for such packages?
  • Use the same http proxy as apt
    • Con: this could be some apt-proxy that doesn't like non-debs

BoF agenda and discussion


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DisconnectedUpgrade (last edited 2010-10-27 20:53:24 by 41)