Has anybody used Google 'Omaha' (their auto-update engine for Chrome)?

Question

Google have open-sourced the auto update mechanism used in Google Chrome:

http://code.google.com/p/omaha/

It seems quite complicated and difficult to configure for anybody who isn't Google. Has anybody used Omaha in a their project? If so, would you recommend it?

Answer 1

An auto-update mechanism is something I'd personally code myself, and always have in the past. Unless you have a multi-gigabyte application and want to upload bits and pieces only, just rely on your own code/installer. That said, I've not looked at Google's open source library at all.. and didn't even know it existed. I can't imagine it offering anything superior to what you could code yourself, and with your own code you aren't bound by any licensing restrictions.

Answer 2

In .NET world you might want to take a look at Click-Once deployment.

Answer 3

Hi Mark,

Perhaps, you can leverage courgette, which is the update mechanism that Google Chrome. It is really easy to use and easy to apply to your infrastructure. Currently, it just works for Windows operating systems. Window users of Chrome receive updates in small chunks, unlike Mac and Linux users who still receive the chunks in total size.

You can find the source code here in the chromium svn repository. It is a compression algorithm to apply small updates to Google Chrome instead of sending the whole distribution all the time. Rather than push the whole 10MB to the user, you can push just the diff of the changes.

More information on how Courgette works can be found here and the official blog post about it here.

It works like this:

server:
    hint = make_hint(original, update)
    guess = make_guess(original, hint)
    diff = bsdiff(concat(original, guess), update)
    transmit hint, diff

client
    receive hint, diff
    guess = make_guess(original, hint)
    update = bspatch(concat(original, guess), diff)

When you check out the source, you can compile it as an executable (right click compile in VS) and you can use the app in that form for testing:

Usage:

  courgette -dis <executable_file> <binary_assembly_file>
  courgette -asm <binary_assembly_file> <executable_file>
  courgette -disadj <executable_file> <reference> <binary_assembly_file>
  courgette -gen <v1> <v2> <patch>
  courgette -apply <v1> <patch> <v2>

Or, you can include that within your application and do the updates from there. You can imitate omaha auto update environment by creating your own service that you periodically check and run courgette.