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I've created a docker container using the following Dockerfile (truncated):
FROM ubuntu:12.04 # curl enables downloading of other things RUN apt-get install curl -y # download and install rvm... RUN \curl -L https://get.rvm.io | bash -s stable # ... so that we can install ruby RUN /bin/bash -l -c "rvm requirements" And so on.
This all works, but the problem I have is how / where the packages are installed.
If I just run rvm using docker run [...] rvm I get "Unable to locate rvm", but if I run docker run [...] /bin/bash -l -c "rvm" it works. (I found the "-l -c" options online, but have no idea what they do, and can't find a satisfactory explanation of what I'm doing!)
This isn't a docker question - it's a bash / *nix question - I presume there's something about how / where things are installed, possibly related to running the install under root?
Just to be clear - I want to be able to run the things that I install direct from the CLI.
EDIT 1
Installing Ruby using rvm is the recommended method, however if you want to run things in a non-interactive, non-login shell (i.e. within a docker container), this just causes too much hassle with paths and environment variables and login scripts not running.
Given that I am using this to run a docker container, which by definition is isolated, and recoverable (just build another one), I don't really care about switching versions, or isolating packages, and so I've decided to install Ruby from a package repo (http://brightbox.com/docs/ruby/ubuntu/) instead. This 'just works'.
It may not work for you - I am only installing Ruby in order to get the Foreman gem, as I am running an app through a Procfile, so I'm not that fussed about the details, I just need it to work. If you're building a Ruby app, I wouldn't follow my advice.
My Dockerfile is here, FWIW, https://index.docker.io/u/yunojuno/dev/
869
Once you have your Docker container up and running, you can work with the environment of the Docker container in the same way you would do with an Ubuntu machine. You can access the bash or shell of the container and execute commands inside it and play around with the file system.
You need an SSH server to get a bash shell inside a container.
A Dockerfile for a database engine may run the database command by default. In that case, if you needed an interactive shell, you'll need to do docker run ... /bin/bash . In general, you can't assume that docker run will give you an interactive shell. It's safer to specify /bin/bash if you need a shell.
From bash(1):
-l Make bash act as if it had been invoked as a login shell-c If the -c option is present, then commands are read from string. You're running the command passed to the -c argument. -l makes it a login shell so bash first reads /etc/profile, which probably has the path to rvm which is what makes it work.
FWIW, here's what I do to install rvm in a docker container.
# Install some dependencies RUN apt-get -y -q install curl rubygems # Install rvm RUN curl -L https://get.rvm.io | bash -s stable # Install package dependencies RUN /usr/local/rvm/bin/rvm requirements # Install ruby RUN /usr/local/rvm/bin/rvm install ruby-2.0.0 # create first wrapper scripts RUN /usr/local/rvm/bin/rvm wrapper ruby-2.0.0 myapp rake rails gem If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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