I'm writing a node module to be open sourced and there's a dependency on some Ruby code (see Can I include a Ruby Gem in a Node.js project? for details). I made a Ruby project that requires some gems and all of that works well. In my node_module, I want to interface it via exec to the Ruby code.
But now there's Ruby dependencies as well. So can I somehow specify the Ruby version, and the gemset required to run my node package?
Ambiguous question perhaps. I can clarify if anything is unclear.
I don't think you can/should specify the Ruby version to use when executing your code. That should be up the library consumer so choose. Since you want to execute your code with exec, the library consumer will have the added responsbility of making ruby accessible to the node process. How that happens is not up to you as the library developer.
As for dependencies/gemsets, just use bundler.
Maybe you could do something like this - without more information it's hard to say.
On the ruby side, build your gem to do whatever it needs to do and then add a rake task to it. How you build this rake task is obviously up to the demands of the project and how it will be used, but it will provide a way for you to interface from the outside.
In the 'middle' build a bash script that includes RVM - this way you can require a specific gemset/do specifc things before running the rake task. Another benefit is that if you want to change the gemset or other implementation details, you just change the bash script.
On the node side, call the bash script. More info on that in this answer.
Related
I want to have a Ruby Gem that will have the same executable as another Gem.
When called with command args it will either do something, or pass the command on to the other Gem.
The first problem I have is that it isn't able to run two same named executables. I get this error:
Bundler is using a binstub that was created for a different gem. This is deprecated, in future versions you may need to bundle binstub yourgem to work around a system/bundle conflict.
How can I have Gems with the same named executables and ensure that the target one executes?
You cannot rely on Bundler or Rubygems to manage this for you. All it does it copy an executable that you specified in your gem spec to its bin/ directory.
The first problem you'll have is that the executable that runs may be dependent on the order in which the gems were installed which you can't guarantee.
Another problem that you'll have is that you cannot execute code on gem installation so you will be unable to run code that would try to automate this set up for people who install your gem.
I believe your gem should provide a non-conflicting executable. You can then supply post install instructions in your gem spec that are displayed to a user installing the gem, in the README, in a blog post, etc. you can tell the user that they need to set up an alias that points to your executable. In all shells that I'm aware of aliases will be executed before filesystem executables.
For the times when people want to bypass your alias and execute the original executable you can tell people to escape the command, e.g. \original-gem. That bypasses alias and function lookup in most shells and will allow users to have your super awesome version as the default (thru the alias) and a way to easily access the original.
[Ruby Noob]
I have a small (command line) utility written in Ruby, which requires a few gems. Is there a way to create a self contained bundle of my program such that I can run it on another machine that has Ruby installed (but not necessarily the gems)?
FWIW, the target machine runs Linux/Ubuntu.
You can use the gem bundle http://gembundler.com/
With bundle you create a Gemfile in your project root - a text that contains all your dependencies, very similar to Maven concept
In order to fetch all your dependencies simply tun
bundle install
The only issue is that you need to have the bundle gem itself installed, so you are back with the chicken-or-Egg problem :-)
I've used:
http://www.erikveen.dds.nl/rubyscript2exe/
before, but it was a while ago. Seemed to work okay for simple programs.
You can download it here:
http://rubyforge.org/projects/rubyscript2exe/
With Jeweler I created a gem folder structure with ease.
However, I still have some questions:
Why are params like --gemcutter and --rubyforge still available for Jeweler. Aren't these replaced by RubyGems? Do I have to specify anything to create a gem for RubyGems?
In the Rakefile I have information about the gem, and when I run "rake install" it created a gemspec. Why is the same information in two places?
What is a manifest? Just read about it, haven't seen such file.
How do I make my gem callable from the shell once I have installed it, like rails. Cause right now it's just accessible through a Ruby script using require.
Should I use "jeweler release" or "gem push" to push my gem to RubyGems.org?
I have to specify "handle" when signing up in RubyGems. What is that?
Thanks.
jeweler was created before RubyGems became what it is, so it still reflects the split. I'm not sure when jeweler was last updated, either. (I think it also still recognizes building gems on Github, which is now disabled.)
I'm not sure I follow what you're saying. The specification in the Rakefile details what the spec that gets written should look like. The spec that gets written details what should be installed and how, I believe.
A manifest is a list of all the files that your gem should ship with. Not everyone uses one. See the hoe documentation for some pro-manifest discussion.
Many Ruby gems are only libraries. If you want yours to also have a program like jeweler or rake or rails that you can call, you have to write the callable program, put it in bin in your gem's layout and specify (in your gemspec) that it should be packaged and installed. See the Gem::Specification reference under files and executable.
Not sure. Consult both jeweler's docs and the docs for RubyGems.
You can give an email address or use a name (a 'handle', like I use Telemachus here), which is all they mean by 'handle'.
For the record, if you are just learning how to write gems, you do not need to upload your first attempts using RubyGems or anything like it. You can simply install the gem on your machine only.
I want to automate things like:
Creating a new Ruby on Rails application with pre-selected database, Git initialize it, create a Heroku project, commit all files, etc.
Upload all files in folder to another computer through SSH, but do not overwrite files.
Upgrade Ubuntu, install all basic packages through apt-get.
From what I understand, tools for this are Rake and Thor, however, which one should I use?
Rake seems to me more de-facto and popular. I have heard people recommending Thor.
How do these stand to each other in a rundown?
Rake and Thor serve different purposes.
Rake is a general build script tool that is project-specific. In other words, you put your rakefile into your project folder and in your project's source control, and you can create, build and do other automation tasks that are specific to your project in that rakefile. Rake requires a rakefile to run.
Thor is a general purpose command line scripting tool that makes it very easy to re-use scripts across many projects and to do project setup, etc., like you are suggesting. Thor allows you to "install" an executable script that you can call from anywhere on your system, similar to calling "ruby", "gem" or "rake" command lines. However, Thor's scripts are more suited to general purpose, cross-application automation because the Thor script does not rely on a file sitting in your project-specific folder. A Thor script is the entire script, packed and installed for re-use anywhere.
Based on your stated needs, you are better off using Thor because you will be able to install your script in one location and have it work anywhere on your system. You will not be bound to where a Rake file is sitting or anything like that.
By the way, Rails 3 uses Thor for pretty much everything that is not project specific. You still have a Rake file and you still run things like "rake db:migrate" or "rake test:units". Thor is used for things like "rails new ...", "rails server" and "rails generate ..." The use of Thor AND Rake in Rails 3 is the perfect illustration of where each of these tools is best suited.
For setting up Ubuntu chores, Chef might be a better option.
From their web site:
Chef is an open source systems integration framework, built to bring the benefits of server configuration management to your entire infrastructure.
It's written in Ruby and there are tons of Chef recipes/cookbooks. Chef will handle setting up Ubuntu and installing packages, servers, etc.
I don't know if you are working with virtual machines, but Vagrant will set up a virtual machine and then use Chef to configure it.
There is something important to mention here.
http://guides.rubyonrails.org/generators.html in its section 8 Application Templates.
You can execute git commands, select gems, capify project.
And you could also execute system commands to satisfy your last point: Upgrade Ubuntu, install all basic packages through apt-get.
I would go with puppet.
By the way, maybe vagrant is useful to you?
I was wondering if there was a solution to automatically - from my ruby source code - ask Gem to install various librairies my code my require to work?
From what i read on the internet, it seems we are obliged to either use an install script that directly runs "gem install ..." commands or do it manually or some people have posted a ruby script that simply iterate over a list of dependencies and use the system command to install them.
Any other better options?
Thanks for your time.
You could use internal RubyGems commands, but that's a pain and error-prone process, especially for dependencies.
I would setup a Gemfile and use Bundler instead. http://github.com/carlhuda/bundler