Updating Rails 2 to Rails 3 or 4

Rails
1

Hi ROR folks,

               Can anyone suggest me is there anyway to update rails

2.X application to Rails 3.X or Rails 4.X

Best Regards,

Gopinath M

2

On Jul 3, 2014, at 10:16 AM, M,Gopi M.gopinath wrote:

Hi ROR folks,

               Can anyone suggest me is there anyway to update rails

2.X application to Rails 3.X or Rails 4.X

You may want to watch this: Rails Conf 2013 Changing the wheels on the bus at 80 mph: Upgrading to Rails 3 - YouTube

It depends a whole lot on your app, and how good your tests are already.
It’s easy (for certain definitions of easy), as the joke goes.

Walter

3

On Thu, Jul 3, 2014 at 7:28 AM, M,Gopi M.gopinath [email protected]
wrote:

                  Seems I need to say this first, The website which I

have Know is 8 Years old website, Developed in Ruby 1.8.6 and Rails 2.3.6,
and its as 220 tables in it and lot of controllers and views. Is there a way
to update this to current version of rails and ruby.

Yes, it’s called “work”. Apply liberally :slight_smile:

Seriously, there’s no magic switch to flip that will vaporize that level
of technical debt.

The pain involved will be inversely proportional to the quality of your
tests, so I’d start there…

Good luck.

Hassan S. ------------------------ [email protected]

twitter: @hassan

4

As was suggested to you by other posters, please read the upgrade guide
carefully (here is the official one
Upgrading Ruby on Rails — Ruby on Rails Guides)

it is recommended that you have very good test coverage before you
begin.

I suggest you use a tool like simple-cov to make sure all your lines of
code are tested before you begin, as well I’d recommend integration
coverage for every major end-user “happy path” through your app.

When you are sure you have complete test coverage, change the version in
the Gemfile and then run “bundle update rails”

5

On Thu, Jul 3, 2014 at 7:49 PM, Walter Lee D. [email protected]
wrote:

It depends a whole lot on your app, and how good your tests are already.

Hi,
Seems I need to say this first, The website which
I
have Know is 8 Years old website, Developed in Ruby 1.8.6 and Rails
2.3.6,
and its as 220 tables in it and lot of controllers and views. Is there a
way to update this to current version of rails and ruby.

6

On 2014-Jul-3, at 11:25 , Jason Fleetwood-Boldt [email protected]
wrote:

Hi,
Seems I need to say this first, The website which I have
Know is 8 Years old website, Developed in Ruby 1.8.6 and Rails 2.3.6, and its as
220 tables in it and lot of controllers and views. Is there a way to update this
to current version of rails and ruby.

The short answer is yes, but it is certainly not easy, nor can you make
a single leap.

Simple-cov will not help you yet as it requires ruby 1.9.3 or better.
(It’s been so long that I can’t even remember if there was a similar
tool that worked with ruby 1.8.6.)

You may find it simpler to write a new app from scratch, importing (by
the time-honored cut-and-paste method) the important bits of business
logic.

However, if you want to proceed with an upgrade, this is roughly what
you’d need to do:

  • update to rails-2.3.18
    There’s really no reason not to and PLENTY of good reasons that you
    should have done this already.
    2.3.9 (2010-09-04) was the version that first gave deprecation
    warnings for the upgrade to rails-3.0
    2.3.18 (2013-03-18) was the last releast in the 2.3 line and contains
    fixes for at least 10 vulnerabilities (some of them quite serious!)

  • get all your tests to pass (if you don’t have tests, you’d better
    have faith)

  • address all the deprecation warnings

  • don’t upgrade ruby yet
    UserVoice Product Feedback, Management and Roadmap Software
    But you might have to upgrade to ruby-1.8.7 as rails-3.0 doesn’t
    officially support 1.8.6)

  • upgrade to rails-3.0.0 (perhaps even directly to rails-3.0.20)

  • get all your tests to pass

  • upgrade to ruby-1.9.2 (or perhaps even ruby-1.9.3)

  • get all your tests to pass

  • upgrade to rails-3.1.12 (last of the rails-3.1 line)
    This might not strictly be required, but 3.1 introduced the Asset
    Pipeline and also made jQuery the default JavaScript framework.
    If you have much use of Prototype or Scriptaculous in your
    application, it would probably be a good idea to convert that to jQuery
    (and get GitHub - rails/jquery-ujs: Ruby on Rails unobtrusive scripting adapter for jQuery)

  • get all your tests to pass

  • upgrade to rails-3.2.19

  • get all your tests to pass

  • upgrade to ruby-2.1.2 (there’s probably no reason to just use 2.0 at
    this point)

  • get all your tests to pass

  • upgrade to rails-4.0.8

  • get all your tests to pass

  • upgrade to rails-4.1.4

  • cope with the new secrets.yml file

  • get all your tests to pass

  • take a vacation

Seriously, there’s a lot to do if you really want to go the upgrade
route. I haven’t even mentioned any of the issues that you’re almost
certain to encounter with gems that cease to function with newer
versions of Rails or even newer Rubies. I’d recommend that you very
seriously consider “refreshing” the application as a simpler way to
bring the application onto a current, supported RoR stack.

-Rob

7

On Jul 3, 2014, at 3:49 PM, Rob B. [email protected]
wrote:

Simple-cov will not help you yet as it requires ruby 1.9.3 or better. (It’s been
so long that I can’t even remember if there was a similar tool that worked with
ruby 1.8.6.)

I think this was the one we used to use back in the Ruby 1.8 days:

8

On 2014-Jul-3, at 15:49 , Rob B. [email protected]
wrote:

  • don’t upgrade ruby yet

But you might have to upgrade to ruby-1.8.7 as rails-3.0 doesn’t officially
support 1.8.6)

Oh, and I took a look at
Upgrading Ruby on Rails — Ruby on Rails Guides as
suggested by Jason Fleetwood-Boldt and that has a MUCH more detailed
walk though the upgrade process from 3.0 to 4.1. But if you don’t have
time to go and look at that yourself, then perhaps I’ve given you enough
with which to weigh the upgrade v. rewrite paths.

-Rob

9

On Jul 14, 2014, at 6:46 AM, tonypm wrote:

I am also using Prototype js, and am wondering whether I should migrate to
JQuery along the way, or get as far as possible with Prototype.

I am still using Prototype in 4.1, this branch is the one that works
without issues for me: GitHub - anamba/prototype-rails: Add RJS, Prototype, and Scriptaculous helpers to Rails 3.1 - 5.2 apps

Walter

10

Rob, this is a useful summary, Thanks.

I face the same problem, having two large apps that are in constant
development and so without putting a stop to development and focusing on
upgrading (something that would be very hard to sell to one of my
clients),
I am strugling to see a way forward. I have got to 2.3.18, and have
been
looking at when to upgrade Ruby, and keeping the right version of gems
and
rubygems seems to also be a challenge along the way.

For me at the moment, the greatest hurdle seems to be when I need to go
to
the asset pipeline in 3.1. Your summary identifies that - thanks. I am
also using Prototype js, and am wondering whether I should migrate to
JQuery along the way, or get as far as possible with Prototype. There
is
not masses of js, but enough to make me wonder. I have done some work
on
3.1 with JQuery, but it could take some effort to implement that in my
current codebase, and I get the sense that things will look quite
different
with the js at Rails 4 anyway.

In giving this ongoing thought, I have been wondering if it would be
possible to upgrade my apps in sections, by breaking them into separate
functional areas, and making them separate apps (perhaps on separate
servers). My thinking being that this might make it possible to upgrade
each section in turn (re-writing straight into Rails 4) and so break the
workload down. I have one section that handles mostly scheduled
maintenance and this is a clear candidate. I would have to mirror the
models, which might become very cumbersome though.

I haven’t got very far with this thinking, and would be interested if
anyone has any thoughts. Another main issue that I can see is the need
to
provide consistent login when a user moves between the apps, but I think
this should be achievable.

I have also seen some stuff written about using engines to help to break
an
app down into more manageable and separate parts and have thought that
this
might also be worth looking into at the same time.

Doing the upgrade in parts would also make it easier to ensure the parts
being upgraded do have up to date tests.

I would be interested on any wisdom from others who have already trodden
this path.

Thanks
tonypm