How to name Dockerfiles

Question

I\'m unsure of how to name Dockerfiles. Many on GitHub use Dockerfile without a file extension. Do I give them a name and extension; if so what? Or do I just ca

Answer 1

Dockerfile (custom name and folder):

   docker/app.Dockerfile
   docker/nginx.Dockerfile

Build:

   docker build  -f ./docker/app.Dockerfile .
   docker build  -f ./docker/nginx.Dockerfile .

Answer 2

Dockerfile is good if you only have one docker file (per-directory). You can use whatever standard you want if you need multiple docker files in the same directory - if you have a good reason. In a recent project there were AWS docker files and local dev environment files because the environments differed enough:

Dockerfile Dockerfile.aws

Answer 3

I think you should have a directory per container with a Dockerfile (no extension) in it. For example:

  /db/Dockerfile
  /web/Dockerfile
  /api/Dockerfile

When you build just use the directory name, Docker will find the Dockerfile. e.g:

docker build -f ./db .

Answer 4

It seems this is true but, personally, it seems to me to be poor design. Sure, have a default name (with extension) but allow other names and have a way of specifying the name of the docker file for commands.

Having an extension is also nice because it allows one to associate applications to that extension type. When I click on a Dockerfile in MacOSX it treats it as a Unix executable and tries to run it.

If Docker files had an extension I could tell the OS to start them with a particular application, e.g. my text editor application. I'm not sure but the current behaviour may also be related to the file permisssions.