Buffet 🍜
Assemble many Dockerfiles in a single Dockerfile. This gives you the convenience of one Docker image with your favorite tools while keeping the modularity of a separate Dockerfile per tool.
See Code Cleaner Buffet for an application of this.
Installation
Run
stack install buffet
or
cabal install buffet
You are ready when
buffet --help
works.
Usage example
Say we work on a simple website with HTML code that we would like to format, clean up, and validate. For this purpose, we choose the tools Prettier and HTML Tidy, which we plan use in continuous integration via a Docker image.
For the following, we assume you first run
git clone https://github.com/evolutics/buffet.git
cd buffet
Assembling
In the subfolders of examples/quick_start
, you see a Dockerfile for Prettier and another Dockerfile for HTML Tidy. These Dockerfiles (called "dishes") are the modular toy blocks, which we now automatically combine to one Dockerfile (called "buffet") by running
buffet assemble examples/quick_start
This prints a Dockerfile based on the subfolders of examples/quick_start
. From this, we can then build a Docker image mona_linta
with
buffet assemble examples/quick_start | \
docker build --build-arg prettier=1.19.1 --tag mona_linta -
Note how in case of Prettier, we pass a --build-arg
to parameterize the tool version.
Testing
As a demo that our Docker image works as expected, run
docker run -it --rm mona_linta
prettier --version
tidy --version
To integrate a check like prettier --version
as a test of the tool installation, add a HEALTHCHECK
instruction as you see in the Dockerfile for Prettier. The exit status of such a command is then reported when you run our example test suite with
buffet test --arguments examples/quick_start/test_arguments.yaml \
examples/quick_start
This builds a Docker image to then run the tests. The file test_arguments.yaml
provides a map that is used for two things: firstly, its entries are used as --build-arg
options when building the image, and secondly, only tests of dishes referred in this map are run.
If you like, try adding a test for HTML Tidy.
Documenting
You can generate documentation with
buffet document --template examples/quick_start/document_template.md.mustache \
examples/quick_start
This renders the template document_template.md.mustache
. To print the raw template context, omit this option as in
buffet document examples/quick_start
Among others, data from LABEL
instructions is integrated in the template context.
Terminology
- Buffet: A Dockerfile automatically assembled based on many dishes.
- Dish: A Dockerfile, usually providing a specific command-line tool.
- Menu: Configuration with a list of dishes to be assembled in a buffet.