Document extra settings for the capistrano-rbenv plugin

[guillehorno]

I found out the extra settings that capistrano-rbenv needs to be able to detect the small differences with the "regular" rbenv (related with this issue: #46) . I've added to the docs in case someone else needs it to. Let me know if you think its ok, or if it needs more explanation or changes.

Thanks!

[FooBarWidget]

Thanks for the pull request @guillehorno, and thanks for figuring out this issue!

I've also done some investigations, and I think the issue can be solved in a better way. Instead of setting rbenv_ruby_dir, we could set:

set :rbenv_custom_path, '/usr/lib/rbenv'

This is the path to fullstaq-rbenv's system-wide installation directory. /usr/lib/rbenv/versions/* are symlinks to /usr/lib/fullstaq-ruby/versions/*. This way, capistrano-rbenv will end up checking whether /usr/lib/rbenv/versions/#{rbenv_ruby} exists.

However, this requires a change on the Fullstaq Ruby side. With the above option, capistrano-rbenv will end up mapping 'ruby' to /usr/lib/rbenv/bin/rbenv exec ruby. However, /usr/lib/rbenv/bin/rbenv does not exist: we don't package it. So we need to modify the fullstaq-rbenv packaging script (container-entrypoints/build-rbenv-{deb,rpm}) to package /usr/lib/rbenv/bin.

We could make things even better if we modify capistrano-rbenv as well. Imagine that, instead of setting rbenv_custom_path, we could set:

set :rbenv_type, :fullstaq

This would make capistrano-rbenv autodetect that rbenv_path should be /usr/lib/rbenv.

Would you like to make these changes? If not, let me know, and I'll do it instead.

If you do choose to make these changes, please don't forget to add a test case as well.

[guillehorno]

Ok, if I understood correctly, the best option would be to add that option on capistrano-rbenv

set :rbenv_type, :fullstaq

This wouldn't need the changes you proposed as a first alternative right? (changing and testing the new packaging scripts). I feel more comfortable making that PR to capistrano-rbenv (it's ruby) instead of modifying and testing the packaging scripts :)

Let me know if thats ok and I'll move forward and make a PR on capistrano-rbenv asking if they are ok with adding the :rbenv_type option.

[FooBarWidget]

The change that I proposed would require a PR to capistrano-rbenv, as well as a change to the fullstaq-ruby packaging scripts:

this requires a change on the Fullstaq Ruby side. [...] capistrano-rbenv will end up mapping 'ruby' to /usr/lib/rbenv/bin/rbenv exec ruby. However, /usr/lib/rbenv/bin/rbenv does not exist: we don't package it. So we need to modify the fullstaq-rbenv packaging script (container-entrypoints/build-rbenv-{deb,rpm}) to package /usr/lib/rbenv/bin.

If you are not comfortable with the latter, then I can pick up that task.

[FooBarWidget]

@guillehorno I've gone ahead and created a pull request for capistrano-rbenv: capistrano/rbenv#92