I set up RVM and used it to install Ruby and a few other libraries. As I was going through various tutorials and set-ups of other technologies like Rails, I began getting confused about what I should do via RVM and what I should just do as the tutorials suggest.
One example is the RubyGems tutorial here:
http://rubygems.org/pages/download
Should I download that tar file they are talking about? Seems unnecessary since that is what I thought RVM was for. Do I even need RubyGems? What is that for really?
Also, how do I actually get Rails? Is there a precise RVM command to actually download and install Rails?
It helps me to think of RVM as a layer of abstraction between you and the ruby ecosystem.
Without RVM: ruby, gems, and ruby related binaries (like rake, spec, gem, etc) are all installed directly into your operating system directories.
With RVM: ruby related stuff is intercepted by rvm so that ruby, gems, and ruby related binares are "installed" into ~/.rvm dir in a nice, clean, organized way. RVM sits between ruby, gems, and related binaries and the operating system. It provides a way to have multiple ruby environments (with different gems and binaries) on the same machine.
So, no matter whether you have rvm installed or not, you should be able to run the commands almost exactly(*) as they appear in any tutorials out there on the web. In other words, you can sort of "forget" that RVM is installed; the ruby ecosystem should work just as if it wasn't installed.
So, yep, you're gonna have to run gem install rails, etc.
Hope that helps clear the confusion.
(*) There are some small differences. For example: you shouldn't run commands as sudo when RVM is installed.
Should I download that tar file they are talking about?
No. Ruby 1.9+ includes gems. RVM retrofits it for 1.8+.
In general, be careful with any directions you find on the internet explaining how to install anything, unless you have enough experience to understand completely what they want you to do. In particular, any time they want you to install something using sudo or as root.
Specifically, when working with RVM, you do NOT want to use sudo to install Ruby, or any gem. RVM works by setting up a sandbox for your development, and relies on your account's environment, modifying your path so any Ruby requests go to the currently selected RVM-managed Ruby or gems or any commands they install. sudo pushes your normal environment to the side, substituting root's temporarily, installs whatever you asked it to do with root's permissions, then reverts to your environment.
When you go to run the command, or find the gem, as you, it can't be found by RVM's Ruby, because the file was installed outside RVM's sandbox, or, it can't be read or modified, because it's owned by root. Whatever the actual cause, the end result will be weeping and gnashing of teeth.
RVM doesn't subvert the gem functionality. gem is used to install and manage Ruby gems, and RVM tweaks it to use the sandbox for all its machinations. You get added functionality because of RVM's support of gemsets, but gem works as it always has, only it has "big brother", RVM, controlling its world.
No need to install rubygems. RVM should have already installed rubygems. RVM is (in my opinion) useful for managing different installations of ruby (say 1.8.7 and 1.9.2) or different gemsets. If you just have one version of ruby and don't care about different gemsets, RVM isn't really that much of a change. If you want to just install rails, just use gem install rails. If you have an existing rails 3 app, install bundler first gem install bundler and then bundle install to get rails and other gem dependencies.
Related
I'm a new Rails developer. I recently took a class on Rails and now I'm trying to make sure I'm growing in my skill by self-assigning projects that push me. One thing I'm trying to do now is use Radiant CMS to build a blog site. However, I'm running into some problems downloading the Radiant gem. Here's what I did:
When I first tried gem install radiant, it installed most of the required gems but then threw a warning (which I unfortunately did not save verbatim), which was along the lines of:
railties executable will overwrite rails executable. Overwrite? Y/n
Stupidly, I chose "Y". As soon as I did I tested my rails gem by writing rails new testproject and it failed. So I then re-ran gem install rails, told it to overwrite the "railties" executable, then ran gem uninstall radiant to get rid of the core radiant gem (although I do still have railties).
Now, my Rails gem is fixed, and I can create new Rails projects without an issue. However, I reinstalled the Radiant gem, and while it installed, it fails to create a project every time I run it.
I'm pretty sure I broke something, but I'm not terribly concerned about that. What I am concerned about is the fact that it seems that the Radiant gem doesn't really coexist well with the Rails gem, which leads me to my question:
Is there any way to create separate, self-contained ruby gem environments where the current Ruby version will only use the gems in the specified environment?
In essence, I'm looking for what rbenv does, but for collections of gems rather than Ruby versions.
Currently, I have Homebrew installed and I am using rbenv as my version manager. Everything I can find so far talks about managing gems on a project-by-project basis; I'm looking for something that will manage and keep separate the gems that create the projects in the first place. So, for example, environment_a contains rails and httparty while environment_b contains radiant and railties.
I'm not above completely obliterating rbenv and all of my gems and starting from scratch, either, so that's a possibility (and an advantage of being a noob).
You should check bundler, as it does exactly what you need.
Yes: rbenv-gemset
I think that it is better than RVM because it is less invasive.
I have been using rbenv and rbenv-gemset for about 2 years and find it easy to use. It makes it easy to encapsulate the Ruby and gemset in a project, run multiple Rubies and gemsets on one machine, and move a project to another machine.
You can use ruby-build to install other versions of Ruby. There is a trick to installing the latest versions of Ruby.
You may want to have a look at How do I ensure ruby gems are installed in right place to be executed by bundler? It has some relevant (and hopefully useful) info.
Yes, there is.
I think that it's called RVM.
Just like Chris Heald said, You can check more information about it # rvm.io/gemsets/basics
I'd recommend bundler for versioning gems although both RVM and rbenv also have this functionality.
You asked: "Is there any way to create separate, self-contained ruby gem environments where the current Ruby version will only use the gems in the specified environment?"
The best way to do it with rvm is entering your project's directory and then run:
rvm use ruby-x.y.z#your_project_name --ruby-version --create
where x.y.z is your Ruby version for that project, previously installed with rvm install x.y.z
For example, to use the newest Ruby version with a project named acme you would use
rvm install 2.3.1
and then
rvm use ruby-2.3.1#acme --ruby-version --create
This command would create two files in the projects directoty: .ruby-version and .ruby-gemset.
The file .ruby-version would contain just the version number. And the file .ruby-gemset would contain only the name off the gemset, the same name of your project (acme).
It happens that rvm is smart enough to check for these files and use the gemset specified, which will be located at ~/.rvm/gems/ruby-2.3.1#acme and your gems will be located at ~/.rvm/gems/ruby-2.3.1#acme/gems.
Some points:
1) Using your project's name as the gemset name is NOT mandatory. You may use anything you like. It's kind of a standard using project's name, but not mandatory.
2) rbenv probably has a way to do the same, but I don't use rbenv and really don't know how to do that.
Hope this answer helps.
I currently use rvm on my dev box (osx) but I use the system ruby on my server (1.8.7 on Ubuntu 10.04)
I want to upgrade the server to 1.9.3 and have been researching the best way to do it.
The server is running about four Rails applications all on version 3.2.11.
My options appear to be using rvm or alternatively using the 1.9.3 deb package and the ruby-switch gem provided by BrightBox (who also provide passenger packages)
The Brightbox packages appear to be a clean way to go but I thought I would ask a question here to see if there are any advantages or disadvantages of either approach that I have not thought about.
Rvm is useful when you need to have two or more versions of Ruby on the same machine. Development machines tend to have this. There is no need to use a version manager if your production box only requires one version of Ruby.
To this effect, I'd suggest you're correct in doing a single installation from the deb package. I can see the ruby-switch gem gives similar functionality to rvm - up to you as to whether that's important. But if you're using three apps on the same version of ruby, it may not be!
As I have started using Linux (Ubuntu) to broaden my knowledge, but the flow for ruby (rails) development does not feel so smooth as on Mac OSX.
Do you use rvm to manage ruby gems in Linux?
One particular issue I face is that I could install rails with only sudo command. But this forces me to use sudo for all the time under my rails project.
P.S.
Might be I am missing some point with the way you do things in Linux so it is not related to ruby (or rails) at all.
It is preferred to use rvm. we can install ruby and rails without rvm as well, but we can have only one version at a time. You can find the instructions to install rvm from following link - rvm installation.
If you are the only person working on ruby rails, install in single user mode(doesn't need to go with sudo)
Installing ruby and rails only using superuser privileges means you're installing it from distribution packages. That's not recommended, and you get unneeded overload writting sudo before any rails command.
Install rvm or rbenv in your home directory and things should be smooth.
What are the benefits & drawbacks of installing things into the #global gemset in RVM?
Let's say I want to install different versions of rails on the same server. I then want the ability to install multiple ruby apps on the same server, with the least duplication of files to save on disk space. However, I still want to avoid dependency problems, gem conflict issues and other problems.
Let's also assume that each app has extra gems it needs that I only want in it's local project gemset.
Would I be better off:
Installing both Rails 3 and Rails 2 gems into the #global gemset
...And use project-local gemsets for their gems...
Installing Rails 3 into a #rails3 gemset, and Rails 2 into a #rails2 set... then cloning for each project I need?
For example:
rvm use ree#rails3 && rvm gemset export rails3.gems
rvm use ree#rails2 && rvm gemset export rails2.gems
rvm use --create ree#project1-on-rails3 && rvm gemset import rails3.gems
Install more project-local gems here...
rvm use --create ree#project2-on-rails2 && rvm gemset import rails2.gems
Install more project-local gems here...
Something else entirely...
NOTE: I wrote this whole response assuming that you are using Bundler to manage your gem dependencies. I realize that some people don't, and you didn't mention Bundler in your question. If you aren't using Bundler, I would point out that it probably is the best way to conserve disk space (only if you bundle install --system, though!). If you are using exported gemsets to manage dependencies, I think your scheme sounds reasonable, but I have no experience with it.
Both Rails 3, and Rails 2 with Bundler will set their load path appropriately such that they will not load any gems (or any versions of any gems) that are not in the Gemfile.lock. There's not really any way that I've experienced to have a "gem dependency problem" on the server. It is important that you run bundle install on your development machine whenever you modify the Gemfile, and that you check your Gemfile.lock into source control, as described on the Bundler homepage.
I spent some time digging into the use-cases of gemsets back in January. The reasons I found to use separate gemsets for each project were:
Your shell environment is the same as your application environment (scripts run correctly without bundle exec).
You can easily browse and grep through the source code of all your dependencies, by navigating to the gemset install directory.
It prevents some reported ‘heisenbugs’, according to the author of RVM. I have experienced something like this where a gem executable wasn't available and bundle exec didn't seem to help.
I don't think any of these benefits are very compelling on the server, so if you are aiming to conserve disk space, I'm not sure why you would use gemsets at all.
Actually, the only reason I've used rvm at all on the server was because it was a convenient way to build ruby from source (we needed a version that wasn't available in the native package manager).
I am looking for a piece of software that will allow me to use Ruby on Rails 2.3.8 on top of MACOSX - basically, I teach at a college where students are not able to get terminal acccess to the rails built into OSX so I am looking for a piece of software like "Locomotive" that is an app that allows students to use rails without administrator access to the computer itself.
Any one have any ideas?
We will be using Rails 2.3.8
thanks.
I encourage you to teach 3.0, but each to their own. If your materials only cover 2.3.8 then it's missing out on a lot of goodies associated with 3.0 (such as Bundler). Anyway:
My primary fear with this is that you're going to have an un-upgradable version of Rubygems if you don't have system privileges. Some gems require a Rubygems version >= 1.3.5 or even better, 1.3.6. Latest is 1.3.7. Thankfully, there's a way around it.
You can do this by installing the rvm gem:
gem install rvm --install-dir ~/.gems
RVM is "Ruby Version Manager" and does what it says on the tin: manages different versions of Ruby on your system. It'd be helpful in your case because it works without modifying the system Ruby.
This will install the gem to the user's home directory rather than the default system path. Then you'll need to run the rvm-install command which, as of this writing is:
~/.gems/rvm-1.0.14/bin/rvm-install
Your version of RVM may be different. To install a new version of Ruby which people can (ab)use run:
rvm install ruby-1.9.2-p0
1.9.2 is the latest stable version of Ruby and I highly encourage you use it rather than the older 1.8.7.
This should come with the latest Rubygems and, for bonus points, won't muddle about with the existing ruby installation on the machine (which is probably impossible if you don't have admin rights).
From this point, you'll be able to use
rvm use ruby-1.9.2-p0
to "switch" to that specific ruby. From there, you'll be able to do run gem install rails -v 2.3.8 which will install Rails somewhere in ~/.rvm. The location is not important. What is important however is that now you'll have a rails command that you can use and then you can go from there.
Good luck!