build-arg not support multiline variable

Troubleshooting

I need to save a multiline variable to a file. But the result is a file with only one line. secrets.DEPLOY_KEY - multiline variable.

      - name: Build SCM container image
        uses: docker/build-push-action@v2
        with:
          push: true
          build-args: |
            VAULT_PASSWORD=${{ secrets.ANSIBLE_VAULT_PASSWORD }}
            PRIVATE_KEY=${{ secrets.DEPLOY_KEY }}

Dockerfile:

ARG VAULT_PASSWORD
ARG PRIVATE_KEY
ENV PASSWORD $VAULT_PASSWORD
ENV KEY $PRIVATE_KEY
...
RUN echo "$PASSWORD" > /etc/vault.txt && \
    chmod 0600 /etc/vault.txt
RUN echo "$KEY" > /root/.ssh/id_rsa && \
    chmod 0600 /root/.ssh/id_rsa

Expected behaviour

cat /root/.ssh/id_rsa
-----BEGIN OPENSSH PRIVATE KEY-----
...
...

Actual behaviour

cat /root/.ssh/id_rsa
-----BEGIN OPENSSH PRIVATE KEY-----

One line only.

PS

Working version if done manually: https://github.com/concourse/docker-image-resource/issues/79#issuecomment-259812953

[crazy-max]

@k0st1an Like secrets, you need to place the key-value pair between quotes:

      - name: Build SCM container image
        uses: docker/build-push-action@v2
        with:
          push: true
          build-args: |
            "VAULT_PASSWORD=${{ secrets.ANSIBLE_VAULT_PASSWORD }}"
            "PRIVATE_KEY=${{ secrets.DEPLOY_KEY }}"

[mindflayer]

Can you give me a link to your repo pls?

Nevermind, it was a false alarm and I am sorry for polluting the thread. Two problems at the same time.