apt-get upgrade and update will break an old Rails app with dependencies?

Question

I am running a Rails 2.3.8 app on my server, with other depended gems, which usually require old version instead of the new version which supports Rails 3.

I have not been running apt-get update and apt-get upgrade on my VPS. I am afraid that running either may upgrade my Rails and other gems to latest version, which will then break my app.

I just wanna update my Ubuntu system, such as security updates and such, without touching any applications.

So, what should I run?

Thanks.

Answer 1

If anything breaks on your system as a result of installing security updates (which is correctly done with apt-get upgrade), then in general it would be a bug in the upgraded package.

Of course, this is assuming that you're not doing oddball things like mixing distribution releases, or using third-party repositories -- in that case, all bets are off and you're totally on your own. So don't do that.

Answer 2

If you want to ensure that your gems don't upgrade during the server update/upgrade, you can add the specific gem version to your environment.rb file.

As an example; rather than just declaring the gem name you can add the version number:

config.gem 'delayed_job', :version => '~>2.0.4'

The above line will ensure the delayed_job gem is installed but only the specific version of 2.0.4.

I notice you said that you don't want to touch the applications. I don't think you can achieve a server-wide update without first manually adding the gem version numbers as I explained above.

Once you have added the version numbers you should be able to run both 'apt-get update' and 'apt-get upgrade' without fear that your applications would break. AFAIK when you update/upgrade the server it will install the newest version of RoR but it won't remove version 2.3.8.