I want to setup gem from rubygems.org to some subfolder of my project like "/gems" and then use it from script via require. Please help me resolve it.
The preferred way is to go with a standard scenario: you build a gem, with binaries, pack it and when used it will download all the dependencies itself, according to gemspec. If the above is for some reason non-acceptable for you, one of the options would be:
• You create a gem for your script;
• You specify a path where to install dependencies:
bundle install --path=vendor/gems
• Instead of require you use require_relative in your script because on destination machines there won’t be local bundle’s config file, pointing to the right folder;
• As your script is finished, you pack everything including gems.
The normal way to go in a ruby project is to setup a Gemfile and use bundler (see link for more info) to handle the gems your project requires, without having to think of where they are stored
However, if there really is no way around shipping an own gem-directory, e.g. because your productive system has absolutely no way to access the internet, you could make it this way:
Create a directory in the root of your project (e.g. 'gems').
Download and unpack the gems to that directory (or use the appropriate options of gem install to redirect the installation into that directory)
Create a ruby file in the root directory of your project with following constants:
PROJECT_DIR = __dir__
GEMS_DIR = File.join(PROJECT_DIR, 'gems')
Now you can require your gems link require File.join(GEMS_DIR, <gem_name>)
Nonetheless, you should really think about using bundler, if possible in any way.
EDIT: to install gem via gem install
Delete the PG data from your project's gems directory
uninstall global gem gem uninstall pg
Install pg again, but into your project's directory: gem install -i <path_to_projects_gems_dir> pg
Run you script again with the require pointing to the gem stated above
I solved it like this:
gem install -i ./ pg
ROOT = File.expand_path('..', __FILE__)
ENV['GEM_PATH'] = File.join(ROOT, './')
require 'pg'
puts 'Version of libpg: ' + PG.library_version.to_s
Related
How do I configure bundler so that when I run bundle install it looks for gems under /my/custom/path first and if it doesn't find there then try to fetch them from a ruby gem remote repository hosted under https://a.nice.host and downloads those into ./local/relative/path (relative to cwd for example). I would like to avoid the bundler looking at default gem installation system path or rubygems.org
The syntax for sourcing a gem from a local folder is:
gem 'some-gem-name', path: '/my/custom/path'
And the syntax for specifying a custom source is:
gem 'another-gem-name', source: 'https://a.nice.host'
And to install gems into a specific local folder, you can run:
bundle install --path ./local/relative/path
Now, that's probably all the tools you need, in truth... (And in fact, especially for that last requirement, you may instead wish to look into rvm gemsets, or using bundle install --deployment.)
But you did also ask about "looking in a local folder first, and only falling back to a remote source if it doesn't exist". That's quite an odd requirement (usually you'd only want to explicitly opt-in to fetching gems from a local path?!), but to answer this question as you've asked it...
A Gemfile is literally just ruby code! So you can define this logic using... You guessed it, ruby! For example:
if File.exists?('/my/custom/path')
gem 'some-gem-name', path: '/my/custom/path'
else
gem 'some-gem-name', source: 'https://a.nice.host'
end
If this (unusual) pattern needs to be repeated in multiple places, you could wrap it into some helper method.
For more information on the configuration options of bundler, please see the documentation.
I'm developing a couple of private gems and I think I don't understand correctly the PATH/GEM_PATH and/or Bundler/RVM installation flow, would love if someone could chip in.
I have a repository with two gems (A & B for simplicity sake). I've developed the gems using the scaffolding + following the guidelines provided by this bundler tutorial.
Thanks to the Bundler project I have a few Rakefile tasks like rake build, rake install, rake install:local and rake release. Because of the private nature of these gems I can't release them to RubyGems (and we haven't looked into hosting our rubygems).
My machines are using RVM to manage ruby versions and Bundler version 1.15.1
What I want to do: Assuming a new machine/developer trying out the project, ideally we would cd into each of the subfolders (currently 2, gem A and gem B), run rake install and after that we should have the gems available system wide for the current user.
What is happening: The gems are built and work properly, but they are only available inside the subfolder of each gem i.e. gem A is only available inside the subfolder A and gem B is only available inside subfolder B.
What I've tried: So, after rake build/install/install:local a new .gem file is generated under pkg. I've tried to manually install the "compiled" file using gem install pkg/A.gem, gem install --local pkg/A.gem and gem install --local --user-install pkg/A.gem without success. (there are plenty of SO questions/answers about this)
I believe this has something to do with the PATH variables, but like I said before I don't fully understand the way they are managed. I get the following results from these commands:
# Our gem
> gem which A
/home/ubuntu/.rvm/gems/ruby-2.4.0/gems/A-0.1.8/lib/A.rb
# Pry, available globally
> gem which pry
/home/ubuntu/.rvm/gems/ruby-2.4.0/gems/pry-0.11.1/lib/pry.rb
I've been lost and frustrated for far too long now, any help is appreciated. Also open to hear suggestions of better private gem installation flows :)
Yes, it has something to do with your PATH variables. Your installation seems to be good.
I advise you to first affirm your gems installation path with:
echo $GEM_HOME
The double check your PATH to ensure its present and also confirm that the GEM home is also where the gem got installed into from the rake install
echo $PATH
If not, put it in your path and you should be fine with something like this:
echo PATH=$PATH:$GEM_HOME >> ~/.bashrc
source ~/.bashrc
Build your gem as per that guide you linked. You should end up with a gem file. Distribute this as you see fit (I use rsync/crontab to download newer gem versions but anything goes). User can install the gem as follows:
gem install --user-install /path/to/your/file.gem
This will install the gem in the user's ~/.gem/ruby/<version>/gems/<your-gem-name> directory.
Tried it with an empty gem (foodie, as in that example guide) and it works fine. But if you don't specify the --user-install parameter it will try to install in the system ruby dir (/usr/lib/ruby/gems...)
I forked a gem I use a lot in order to code some enhancements on it. I want it to be installed in a subfolder called ~/codebase/ruby, where I keep all my Ruby projects, arranged in subdirectories.
To do that, I built and installed the gem with the following commands:
gem build my_gem.gemspec
gem install mygem-x.x.gem -i./mygem
mygem is installed in ~/codebase/ruby/mygem. I can't get my client code (which is in another directory) to grab mygem from there.
I've tried all of the following without success:
Running ruby with argument -I<path_to_mygem>.
Adding <path_to_mygem> to PATH.
Putting :gempath: <path_to_mygem> into ~/.gemrc.
I know I could put the gem in ~/.gem/ruby/<version> (since it appears in gem env) and that would probably work, but that would break my existing directory structure of Ruby code, forcing me to code in a different directory only for mygem, which is something I want to avoid unless it's the only option.
Thoughts?
Hopefully you are using Bundler to load the required gems. Then you just specify the path to the gem file in your Gemfile:
gem 'my_gem', :path => '~/codebase/ruby/mygem'
Is it possibile to have something like a 'local' gem repository for Ruby?
I'm working on a custom Linux distribution without admin rights. Ruby is installed on the machine (v.1.8.7) but apparently no 'gem' or 'bundle' or whatever are installed. I need to use some Ruby gems like Nokogiri.
Is it possible to use Ruby gems without installing them through gem install?
Yes. Any gem can be used standalone. You just have to either download the source from github, or download the gem and extract its contents manually.
After you've done that you have to add the lib folder of the gem into the load path ($:) of Ruby. For example:
$:.unshift(File.expand_path("nokogiri-1.6.1/lib"))
require 'nokogiri'
Assuming you are running Ruby in the current directory and the Nokogiri source is in the folder nokogiri-1.6.1.
But remember that first you have to do the same with all Nokogiri prerequisites. I.e. all the libraries Nokogiri depends on.
Another option, which is what I would do, is to install RubyGems in your home directory. That can get a little bit tricky though, but it's possible by downloading the RubyGems package and running something like:
ruby setup.rb --prefix=/home/my_user_name/rubygems
Then you need to set up the ENV variables GEM_HOME and GEM_PATH to point to a location in your home directory where you want all your gems to be installed. See "What's the difference between GEM_HOME and GEM_PATH?" for a description of what they do.
You will also need to add something like /home/my_user_name/rubygems/bin to your PATH so that the gem command can be found by the shell.
I'm working on a project currently that I don't want to be a gem (or some other kind of project). How would I go about setting it up so that I can still have the same compatibility requirement abilities as a gem (e.g. Gemfile dependencies) but simultaneously not be a gem (or some other kind of project)?
You have to actually try to build a gem so this is easy!
to use bundler without Rails, a gem, whatever just create a directory
mkdir my-non-gem-project
cd my-non-gem-project
install bundler
gem install bundler
and initialize your Gemfile
bundle init
that will create a Gemfile for you and you can add to it and run bundle to install the dependencies from it
The simplest way to use bundler in your project would then be to open your main app file and add
require 'bundler/setup'
Bundler.require
This will require all of the gems you have in your Gemfile in the file this is added to. I am pretty sure that this file must be in the same directory as your Gemfile. More information here
Have fun with your Ruby project!