Prompting for username/password with git clone from Dockerfile run step

Question

I'm trying to set up a multi-stage docker build and needing to cloning my sources for the initial first stage build step.

However, git clone requires a username/password as the path to the repository is on a private github enterpr server. Under normal circumstances git will prompt you for the username/password. However, with git clone started from a RUN step in the Dockerfile there is no such prompt and the output is simply:

fatal: could not read Username for 'https://yourserver.com': No such device or address The command '/bin/sh -c git clone https://yourserver.com/name/yourpath' returned a non-zero code: 128

Even with the -ti flag specified in the docker build step. How do I pass the username/password or at least prompt for it? I don't want this embedded in the Dockerfile.

Answer 1

If you want to git clone with user/password, all you need to do is

git clone https://username:[email protected]/username/repository.git

In your case it would be

RUN git clone https://username:[email protected]/username/repository.git

A better solution would be to create a set of private/public keys without a password and ADD or COPY the private key into your Dockerfile. In that case you will need to register the public key with github. Then the simple command will suffice:

RUN git clone ssh://[email protected]/username/repository.git

UPDATE

I also had an idea based on my answer here. If you need different usernames/passwords to use, you could set an ARG in your Dockerfile: ARG USERNAME=user ARG PASSWORD=1234 And then build your image with docker build --build-arg USERNAME=user --build-arg PASSWORD=1234 .` And you will get at least some simulation of user input :)

The solution I posted above (in "spoiler" now) is not safe. As per actual docs:

Warning: It is not recommended to use build-time variables for passing secrets like github keys, user credentials etc. Build-time variable values are visible to any user of the image with the docker history command.