I'm in the same boat raised in Issue 78, and later defined in the Using the docker/build-push-action Action together with multiple Deploy Keys section of the readme. I.e., I need multiple ssh keys to be used as deploy keys for multiple Github repos, in the context of docker build.

The only difference between that and my use-case is that I'm not using the build-push-action, but manually building & pushing. I don't think that difference is related to the problem I'm seeing, but I could be wrong. I'm passing the ssh agent socket into the docker build manually like so:

- name: Build Docker image run: | DOCKER_BUILDKIT=1 docker build --ssh default=${{ env.SSH_AUTH_SOCK }} --tag our-stuff/our-stuff:tag --file our_dockerfile . 

To verify, I have all 4 separate ssh public keys installed in 4 of our private repos as deploy keys, and the corresponding private keys installed in our org as CI secrets. We're running on our self-hosted runner, and using a base image we've made with some of the tools we need pre-installed.

I have my ssh setup in the action in the way defined in the README:

... runs-on: [self-hosted] container: /our/container/path/here:tag steps: - uses: actions/checkout@v3 - uses: webfactory/ssh-agent@v0.7.0 with: ssh-private-key: | ${{ secrets.GH_DEPLOY_KEY_REPO_ONE }} ${{ secrets.GH_DEPLOY_KEY_REPO_TWO }} ${{ secrets.GH_DEPLOY_KEY_REPO_THREE }} ${{ secrets.GH_DEPLOY_KEY_REPO_FOUR }} - name: Prepare git and ssh config for build context run: | mkdir root-config cp -r ~/.gitconfig ~/.ssh root-config/ ... 

And I added the relevant lines to my dockerfile:

COPY root-config /root/ RUN sed 's|/home/runner|/root|g' -i.bak /root/.ssh/config 

However, I get this error on the sed command:

sed: can't read /root/.ssh/config: No such file or directory 

When I add this to the workflow after the above blocks:

- name: Confirm original ssh directory run: | ls ~/.ssh - name: Confirm copied ssh directory run: | ls root-config/.ssh 

... it only shows known_hosts being present in both directories. And when I do the same ls in the dockerfile, same thing.

I feel like I'm probably looking right at the problem, but I can't see it.