From 5e7bd3add196c8acf0bde87405e0a3ac6e3f956c Mon Sep 17 00:00:00 2001 From: "Nadav.Ruskin" Date: Sun, 11 Mar 2018 16:18:00 +0100 Subject: [PATCH] Updated readme to include instructions on extending images. --- README.rst | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/README.rst b/README.rst index de5bc66..38e527e 100644 --- a/README.rst +++ b/README.rst @@ -286,6 +286,27 @@ Note that commands are executed verbatim. If any shell processing for environment variable expansion or redirection is required, please use `bash -c 'command args...'`. +How to extend Dockcross images +------------------------------ +In order to extend Dockcross images with your own commands, one must: + +1. Use ``FROM dockcross/``. +2. Set ``DEFAULT_DOCKCROSS_IMAGE`` to a name of the tag you're planning to use for the image. This tag must then be used during the build phase, unless you mean to pass the resulting helper script the ``DOCKCROSS_IMAGE`` argument. + +An example Dockerfile would be:: + + FROM dockcross/linux-armv7 + + ENV DEFAULT_DOCKCROSS_IMAGE my_cool_image + RUN apt-get install nano + +And then in the shell:: + + docker build -t my_cool_image . # Builds the dockcross image. + docker run my_cool_image > linux-armv7 # Creates a helper script named linux-armv7. + chmod +x linux-armv7 # Gives the script execution permission. + ./linux-armv7 bash # Runs the helper script with the argument "bash", which starts an interactive container using your extended image. + Articles --------