How to deploy Rails app and install Ruby Native Extension in user directory

Question

Does anyone know a way to deploy to a server and have the native extensions installed in a user directory?

I'm using capistrano and bundler and don't have write access to /usr/local... Gems with Native extensions (in the current case, bcrypt-ruby) don't install. My initial problem was an inability to find "config.h."

On some investigation of the generated Makefile, this line is the culprit:

 $(OBJS): $(hdrdir)/ruby.h $(hdrdir)/ruby/defines.h $(arch_hdrdir)/ruby/config.h

Mkmf defines arch_hdrdir this way:

arch_hdrdir = $(extout)/include/$(arch)

Why it does this is a bit baffling. Unfortunately, $extout is "", so as a result, Make is looking for config in /include/i686-linux/ruby/config.h and fails.

Further investigation into mkmf lead me to think $extout being set to something that evaluates to true in install_dirs, but ends up being an empty string in the makefile. But, I can't figure out where it's getting set.

To shake things up, I've tried setting $extout in extconf.rb. But...

1) If I set it to '/usr/local/lib/ruby' the makefile tries to install the .so into /usr/local/lib/ruby... where I don't have write access. Boo.

2) I have tried setting $extout to '/home/crivens/railsapp/shared/bundle'. This actually compiles, but then the application can't find the .so file. And I had to do a bunch of hacks to get there.

After spending a bunch of time on this, I'm looking for suggestions!

Is it even possible to install a gem with native extensions without access to the system repository?
What would be the best strategy for doing so?
Is mkmf documented anywhere? (I sure can't find much of note)
What is $extout for and how does it get set?

Thanks in advance.

score 1 · Accepted Answer · edited May 23 '17 at 11:56

I think what you're looking for is ruby version manager (rvm). It's available here and allows you to manage versions of Ruby, Rails, and Gem sets.

https://rvm.io/

There's a good getting started guide here as well: http://rvm.beginrescueend.com/rvm/install/

Here's how the install goes:

[sam@mungr ~]$ \curl -L https://get.rvm.io | bash -s stable --ruby
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 10956  100 10956    0     0   2240      0  0:00:04  0:00:04 --:--:--  2240
Please read and follow further instructions.
Press ENTER to continue.
Downloading RVM from wayneeseguin branch stable
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 1243k  100 1243k    0     0   570k      0  0:00:02  0:00:02 --:--:--  929k

Installing RVM to /home/sam/.rvm/
    Adding rvm PATH line to /home/sam/.bashrc /home/sam/.zshrc.
    Adding rvm loading line to /home/sam/.bash_profile /home/sam/.zprofile.

# RVM:  Shell scripts enabling management of multiple ruby environments.
# RTFM: https://rvm.io/
# HELP: http://webchat.freenode.net/?channels=rvm (#rvm on irc.freenode.net)
# Cheatsheet: http://cheat.errtheblog.com/s/rvm/
# Screencast: http://screencasts.org/episodes/how-to-use-rvm

# In case of any issues read output of 'rvm requirements' and/or 'rvm notes'

Installation of RVM in /home/sam/.rvm/ is almost complete:

  * To start using RVM you need to run `source /home/sam/.rvm/scripts/rvm`
    in all your open shell windows, in rare cases you need to reopen all shell windows.

# sam,
#
#   Thank you for using RVM!
#   I sincerely hope that RVM helps to make your life easier and
#   more enjoyable!!!
#
# ~Wayne


rvm 1.17.7 (stable) by Wayne E. Seguin <wayneeseguin@gmail.com>, Michal Papis <mpapis@gmail.com> [https://rvm.io/]

No binary rubies available for: downloads/ruby-1.9.3-p362.
Continuing with compilation. Please read 'rvm mount' to get more information on binary rubies.
Fetching yaml-0.1.4.tar.gz to /home/sam/.rvm/archives
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  460k  100  460k    0     0   342k      0  0:00:01  0:00:01 --:--:--  492k
Extracting yaml to /home/sam/.rvm/src/yaml-0.1.4
Configuring yaml in /home/sam/.rvm/src/yaml-0.1.4.
Compiling yaml in /home/sam/.rvm/src/yaml-0.1.4.
Installing yaml to /home/sam/.rvm/usr
Installing Ruby from source to: /home/sam/.rvm/rubies/ruby-1.9.3-p362, this may take a while depending on your cpu(s)...
ruby-1.9.3-p362 - #downloading ruby-1.9.3-p362, this may take a while depending on your connection...
ruby-1.9.3-p362 - #extracting ruby-1.9.3-p362 to /home/sam/.rvm/src/ruby-1.9.3-p362
ruby-1.9.3-p362 - #extracted to /home/sam/.rvm/src/ruby-1.9.3-p362
ruby-1.9.3-p362 - #configuring
ruby-1.9.3-p362 - #compiling
ruby-1.9.3-p362 - #installing 
Retrieving rubygems-1.8.24
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  371k  100  371k    0     0   430k      0 --:--:-- --:--:-- --:--:--  611k
Extracting rubygems-1.8.24 ...
Removing old Rubygems files...
Installing rubygems-1.8.24 for ruby-1.9.3-p362 ...
Installation of rubygems completed successfully.
Saving wrappers to '/home/sam/.rvm/bin'.
ruby-1.9.3-p362 - #adjusting #shebangs for (gem irb erb ri rdoc testrb rake).
ruby-1.9.3-p362 - #importing default gemsets (/home/sam/.rvm/gemsets/), this may take time ...
Install of ruby-1.9.3-p362 - #complete 
Creating alias default for ruby-1.9.3-p362.
Recording alias default for ruby-1.9.3-p362.
Creating default links/files
Saving wrappers to '/home/sam/.rvm/bin'.

  * To start using RVM you need to run `source /home/sam/.rvm/scripts/rvm`
    in all your open shell windows, in rare cases you need to reopen all shell windows.

Once complete I've got a fully functional install of Ruby 1.9.3-p362:

[sam@mungr ~]$ source /home/sam/.rvm/scripts/rvm
[sam@mungr ~]$ rvm list

rvm rubies

=* ruby-1.9.3-p362 [ x86_64 ]

# => - current
# =* - current && default
#  * - default

Which version of Ruby?

[sam@mungr ~]$ which ruby
~/.rvm/rubies/ruby-1.9.3-p362/bin/ruby

A little Hello World

[sam@mungr ~]$ ruby -e "puts 'Hello world'"
Hello world

EDIT #1

Through the course of discussing this question the author, Crivens, noted that he was getting the following error:

Error curl: (77) Problem with the SSL CA cert (path? access rights?) and OS is Linux version 2.6.32-042stab055.16 (root@rh6-build-x64) (gcc version 4.4.4 20100726 (Red Hat 4.4.4-13) (GCC) ) #1 SMP Fri Jun 8 19:22:28 MSD 2012. I'm still hoping to use the system install of ruby.

If you encounter this error it usually means one of two things:

1. I think you're just missing this RPM, ca-certificates-2010.63-3.el6. These are the certificates. My install of RVM on a Ubuntu 8.04.4 machine fails. Should I install it as multi-user instead?

solution #1

% yum install ca-certificates-2010.63-3.el6

2. The developer for rvm, Wayne, changed the URL from rvm.beginrescueend.com to rvm.io and probably wonked the SSL certs. Curl Certificate Error when Using RVM to install Ruby 1.9.2

solution #2

% curl -L get.rvm.io | bash -s stable

-or-

% echo insecure > ~/.curlrc

I had thought of that. I think that this basically installs another version of ruby in /home/crivens/... Actually went to try this but ran into another problem, the rvm install script started complaining about certificates. I looked at this briefly, but thought it might be easier to figure out hot to use the already installed ruby. Might be a good Plan B (or C) though. — Crivens, Jan 07 '13 at 02:37
Error `curl: (77) Problem with the SSL CA cert (path? access rights?)` and OS is `Linux version 2.6.32-042stab055.16 (root@rh6-build-x64) (gcc version 4.4.4 20100726 (Red Hat 4.4.4-13) (GCC) ) #1 SMP Fri Jun 8 19:22:28 MSD 2012`. I'm still hoping to use the system install of ruby. — Crivens, Jan 07 '13 at 03:38
I don't think you'll be able to use the system install of ruby the way you intend too very easily. I don't want to say it's impossible b/c nothing usually is in Unix/Linux but the effort to figure it out is what you've got to size up and I'd take my chances with getting rvm working over your alternative. I've got 20+ years of Unix/Linux experience when I say that. — slm, Jan 07 '13 at 03:48
I'm still hoping to fix mkmf, but in the absence of any other ideas, I worked on getting rvm installed last night. This solution was the first thing that worked out of a half a dozen tries: [link](http://stackoverflow.com/a/11780019/1797331). I ran into a couple of problems with deployment but think that's working. So now I'm stuck trying to get passenger to work with my app. It's having problems finding the gem's (or at least the native extensions) and I'm not sure it's running the rvm ruby. I don't know much about apache and passenger so have some reading to do. — Crivens, Jan 08 '13 at 13:29
Well, after a few other problems (mainly around finding gems with bundler, rvm, capistrano, and the system-installed ruby), I get this all to work. So @slm was right (and I still haven't figured out how to get mkmf to build native extensions with the setup I've got). — Crivens, Jan 13 '13 at 17:16

score 0 · Answer 2 · answered Feb 11 '13 at 23:32

If you don't want to install RVM or rbenv in the server for any reason, you can still install the gem from the server with a user who has permission (root?) permission, using:

gem install bcrypt-ruby --install-dir /path/to/deploy/shared/bundle/ruby/1.9.1/`

Afterwards, bundle will just take that gem. Of course, if you update the gem in the Gemfile you should repeat this.