Git clone with ssh in docker image build

Question

I'm building a docker image, and I want to clone a repository from bitbucket.

If I create a `debian' container and execute step-by-step, everything works fine. But when I try to create the image, it does not work.

I have added the key to bitbucket settings.

Here is my Dockerfile

FROM debian:stretch

RUN apt-get update && apt-get -y upgrade && apt-get -y install nginx curl software-properties-common gnupg git
RUN curl -sL https://deb.nodesource.com/setup_6.x | bash -
RUN apt-get install -y nodejs

RUN mkdir /backend

RUN npm install pm2 ts-node -g

WORKDIR /backend
RUN mkdir /root/.ssh
RUN echo -e "-----BEGIN RSA PRIVATE KEY-----\n(...)-----END RSA PRIVATE KEY-----" >> /root/.ssh/id_rsa
RUN chmod 400 /root/.ssh/id_rsa
RUN ssh-keyscan bitbucket.org >> /root/.ssh/known_hosts
RUN git clone [email protected]:xxx/xxx.git

Here is the error:

Cloning into 'xxx'...
Warning: Permanently added the RSA host key for IP address '104.192.143.3' to the list of known hosts.
Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

How can I create this image to work properly?

Answer 1

If you are sure the correct public key is in bitbucket, the answer (in my experience) is almost always the permissions on the .ssh folder and files within. I see above that you just create that folder and the private key within, but do not update permissions.

Expected Permissions

.ssh should be:

drwx------  2 user user 4096 Feb  6 11:18 .ssh

The private key:

-rw-------  1 user user 1675 Feb  6 11:18 id_rsa

Finally your home dir should at the very least not be writable by group or other, generally you want:

drwx------ 84 user user 16384 Feb 16 18:23 user

Putting it all together:

chmod go-w /root
chmod 700 /root/.ssh
chmod 600 /root/.ssh/id_rsa