I am aiming to have a production machine running a Ruby on Rails app. However, this production machine is managed with Plesk and allows only very rudimentary access, but was promised to be able to run Ruby on Rails apps.
Indeed it is in principle able to run Ruby on rails for an overly simple example, but running any app requiring gems with native extensions (as e.g. nokogiri, which is required already by the rails default app, generated by rails new) already fails.
Part of the log looks like this:
libruby.so.2.4: cannot open shared object file: No such file or directory - /var/www/vhosts/hosting116285.a2f45.netcup.net/test.gcsb.info/vendor/bundle/ruby/2.4.0/gems/msgpack-1.2.6-x86_64-linux/lib/msgpack/msgpack.so (LoadError)
/var/www/vhosts/hosting116285.a2f45.netcup.net/test.gcsb.info/vendor/bundle/ruby/2.4.0/gems/msgpack-1.2.6-x86_64-linux/lib/msgpack.rb:11:in `require'
...
...
...
/var/www/vhosts/hosting116285.a2f45.netcup.net/test.gcsb.info/vendor/bundle/ruby/2.4.0/gems/rack-2.0.6/lib/rack/builder.rb:55:in `initialize'
config.ru:1:in `new'
config.ru:1:in `<main>'
/usr/share/passenger/helper-scripts/rack-preloader.rb:110:in `eval'
/usr/share/passenger/helper-scripts/rack-preloader.rb:110:in `preload_app'
/usr/share/passenger/helper-scripts/rack-preloader.rb:156:in `<module:App>'
/usr/share/passenger/helper-scripts/rack-preloader.rb:30:in `<module:PhusionPassenger>'
/usr/share/passenger/helper-scripts/rack-preloader.rb:29:in `<main>'
I have the options to "restart the app", "install packages" (which executes a bundle install --path vendor/bundle according to documentation), and "add environment variables".
I have very limited SSH access to the machine, but no access to any compilers or libraries.
The support advised me to "precompile my gems", but did not give any specific advice how to do this. I set up a virtual development machine which is somewhat near to the production machine, but definitely not yet the same in terms of all paths and e.g. Linux kernel version. I compile with gem-compiler (https://github.com/luislavena/gem-compiler) which supposedly works fine, but the precompiled gems in bundle/cache, and install them via the Plesk interface.
However, the app keeps throwing errors. The pre-compiled gems (msgpack is one of them; originally with native extensions) seem to be linked in a wrong fashion? I have honestly no idea anymore. I already tried packing my development machine's libruby.so.2.4 onto the production machine, which reduced the errors a little but did not help to solve it.
Do you have any suggestions of an advisable strategy to circumvent the given limitations? Am I doing it right, but it is simply not possible to make it run in this environment?
Thanks in advance!
Robert
