There are few ways we can create an application with specific rails version.
In this article, we will create a new rails app of version
6.0.1 while our system may have multiple rails versions installed in our system.
Here is the list of rails versions that were already installed in my system while writing this article.
rails (184.108.40.206, 220.127.116.11, 6.0.1)
Method 1: Common method
Let’s start with most common and widely documented method:
rails version new app_name
Let’s create an app named
my_app with rails version
gem install rails -v 6.0.1 #only when the gem has not been installed in the desired ruby version you are using rails _6.0.1_ new my_app
_6.0.1_feature is provided by
RubyGems. It checks if the first argument(
ARGVArray) is a version. It then modifies the $LOAD_PATH accordingly. Ruby seeks help from
RubyGemsbecause it knows where the gems are stored.
Hence this code will fail if you are currently using a different version of Ruby and in that particular version of Ruby that particular version of the gem might has not been installed. Thank you Shiva Bhusal for pointing out the problem and solution in the comments.
Method 2: Let bundler handle the rails version
In this method we will let
bundler handle rails version.
Our workflow if we wanted to setup new project with rails version
6.0.1 would be:
2.1: Make new folder and initialize bundler
# make directory for new rails app mkdir my_app cd my_app # specify ruby version we want to use echo 2.4.1 > .ruby-version # initialise bundler (creates Gemfile) bundler init
2.2: Specify rails version
At this stage, our
Gemfile probably looks like this:
# A sample Gemfile source "https://rubygems.org" # gem "rails"
We have to uncomment rails gem and specify version so that our
Gemfile looks like this:
# A sample Gemfile source "https://rubygems.org" gem "rails", '6.0.1'
Now we need to run
bundle install. (This would install
rails 6.0.1 if it had not been installed yet).
2.3: Initialise new rails app with specified rails version
At this point we already have minimal project with rails version
Now, we can use the rails command line tool with bundle exec to force the version:
bundle exec rails new . --force # --force to overrite curent Gemfile
If you were unaware about rails runtime option
force, it is used to overwrite files that already exist. Just type
rails in your commandline and you will see explanation about this command.
Now, we have new rails project with our desired rails version(
What do you think about this flow of setting up version specific new rails project? Feel free to comment.