I appreciate all the answers out there as to what bundle exec does, which is that it runs the following commands in the context of the Gemfile bundle. But why doesn't "rails server" need bundle exec? Seems like it should still apply.
The rails command runs from the executable inside the script folder. If you remove this folder, you can see that rails commands stop working. rake however runs differently.
Related
What is the difference between using bin/rake and bundle exec rake.
And which is one preferred style?
bin/rake db:migrate
bundle exec rake db:migrate
bundle exec executes a command in the context of your application.
As each application can have different versions of gem used. Using bundle exec guarantees that you use the correct versions.
I use bundle exec always instead of rake because i have multiple applications running on my system.
Try to use bundle exec rake db:migrate always.
You can learn more about it here Official documentation
bin/rake is a kind of stub for the rake command from bundled Gems. It has exactly the same function as bundle exec rake. See http://bundler.io/v1.14/man/bundle-install.1.html and search for binstubs for more about stub. And also note that bin/rake and bin/rails are stubs generated by Rails, which are different in code from the stubs generated by bundler. However, they all serve the same purpose and have the same function.
You have 3 options on a typical system:
bin/rake db:migrate
rake db:migrate
bundle exec db:migrate
The first option is simply calling the path to the rake program, whose launcher can be found in the hidden /bin folder. This launcher is usually just a symlink to the program's content found in your /.rvm directory. You can find its original location by executing $ which rake, which will give you something like /home/ubuntu/.rvm/gems/ruby-2.2.3-p481#devonzuegel/bin/rake.
By default, the second option is essentially the same as the first on most systems. It's what is called an alias, which is basically just a shorthand command for some other program. This is defined somewhere in your shell settings as something like alias rake='/bin/rake'. It's possible that this alias is pointed to a different program on your machine though, so check that before taking my word for it.
When you use bundle exec you're telling bundler to ensure that only the gems and their specified versions from your Gemfile.lock are loaded. This will only work if you're in a directory that contains a Gemfile.lock or whose parent/grandparent directory contains one.
I am seeing many times the question about execution of bash files inside rake (task) files.
My question is, how to execute a rake command inside the bash file?
I have a migrate.sh file inside each rails app on my server and I'm using a general publish.sh. All of this runs ok.
Then, I have a command like rake tmp:clear assets:clean log:clear RAILS_ENV=production inside each migrate.sh that gives me a rake: command not found error.
Help?
Basically rake is not resolved as the PATH variable is not correct. You can try doing echo $PATH. Also you can create a bash script and provide some environment variables required by rake like this:
#!/bin/bash
GEM_HOME=/home/tuxdna/.gems
SHELL=/bin/bash
USER=tuxdna
PATH=/home/tuxdna/.gems/bin:/usr/lib/ruby/gems/1.8/bin/:/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/games
GEM_PATH=/home/tuxdna/.gems:/usr/lib/ruby/gems/1.8
cd ~/somesite
export RAILS_ENV=production
bundle exec rake mytask:task1
klashxx's supposition was correct. It was a permissions/profile issue. I had change my user to root to be able to do other previous tasks and found out that my root was not able to run rake tasks.
This will not be an issue on production server though.
Thanks klashxx
guys! I am a newbie for Ruby on Rails and refinerycms.
Currently, I am study the refinerycms. I want to find all the missing key so as to translate refinerycms. According to the tutorial, I should run the command
bundle exec rake refinery:testing:dummy_app
so as to enable additional useful rake tasks. But when I run this command, it says
rake aborted!
Don't know how to build task 'refinery_testing:dummy_app'
Does any one know the reason?
BTW, I have already added the gem "refinerycms-testing" to Gemfile and installed it already, and I also in the root directory of the project.
I think your problem is that you are not in the good directory.
cd vendor/extension/your_extension_name
bundle exec rake refinery:testing:dummy_app
Hope it helps,
-frbl
I learned Rails using just the rake command like rake db:migrate; however, I read that I should be using the bundle exec rake ... instead of just plain rake. Now I'm confused about which to use.
Should I be using bundle exec rake instead of just plain rake or is it just a preference thing? Any insight would be much appreciated! Thanks!
bundle exec executes a command in the context of your bundle.
That means it uses the gems specified in your Gemfile. Much of the time, running bundle exec rake foo has the same results as if you just ran rake foo, especially if you have the same gems installed systemwide as in your Gemfile. However, some applications may specify different versions of gems than the ones you have installed systemwide, and may want those exact gems and versions to be able to run correctly. If you just run without bundle exec, you may get some weird errors.
Using bundle exec guarantees that the program is run with the environment specified in the gemfile, which hopefully means it is the environment that the creators of the program want it to be run in, which hopefully means it should run correctly no matter what weird setup you have on your computer.
It basically standardizes the environment under which the program is run. This helps avoid version hell and makes life much easier.
See http://bundler.io/v1.3/man/bundle-exec.1.html for more info.
$ bundle exec rake db:migrate
Uses the version of rake specified in the Gemfile to execute the rake task db:migrate.
But there is no rake gem specified in the Gemfile!
Yes, but a rake gem was installed as a dependency of some other gem--look in Gemfile.lock. So the rule must be: Uses the version of rake specified in Gemfile.lock.
But Gemfile.lock doesn't specify a specific version--it specifies a version greater than x.y!
Then the rule must be: Uses the version of rake that was installed in the current gemset.
$ rake db:migrate
Normally, when you issue a command on the command line, e.g. rake, your system searches for the command in the list of directories specified in your PATH environment variable. The first directory that contains the command is the version of the command that is used. To see which directory that is, you can do:
$ which rake
So if you execute,
$ rake db:migrate
that may use a different rake gem than the one you installed with bundle install. But, even if your system finds the same rake version as bundle exec, any gems required by the rake source code will be searched for in places outside your project's gemset. Therefore, there are many ways that just:
$ rake db:migrate
can screw things up.
According to the Ruby on Rails Tutorial Book(free online), section 3.6, if you are using rvm 1.11.x+ then you do not need to preface commands with bundle exec.
running any exacutable without bundle exec will have Rubygems fetching the latest version of the gem installed in your system.
By adding the bundle exec prefix instead will have the executable running in the context of your Gemfile.lock, which means that will be run using the version defined in the gem file.
In Rails 2 you're able to run
script/console --sandbox
so you can play with production data and not accidentally break anything.
I can't seem to find the equivalent command for Rails 3. Does anyone know what it is?
Easy, type in:
bundle exec rails c -s
and that is it.
$ bundle exec rails c --help
Usage: console [environment] [options]
-s, --sandbox Rollback database modifications on exit.
--debugger Enable ruby-debugging for the console.
--irb DEPRECATED: Invoke `/your/choice/of/ruby script/rails console` instead
It is simple, but, sometimes, if you are not running rails executable using bundle exec, it may, or may not, result in an error. In order to avoid this, ALWAYS use bundle exec.
To quote bundler page (if not documentation):
In some cases, running executables without bundle exec may work, if
the executable happens to be installed in your system and does not
pull in any gems that conflict with your bundle.
However, this is unreliable and is the source of considerable pain.
Even if it looks like it works, it may not work in the future or on
another machine.