Docker build failing

[qstokkink]

Our new Docker build job is failing with the following error:

/usr/bin/docker buildx build --build-arg GIT_BRANCH=main --build-arg GIT_REPO=https://github.com/Tribler/tribler --file build/docker/build.Dockerfile --iidfile /home/runner/work/_temp/docker-actions-toolkit-jld9CF/build-iidfile-fdf01b78ae.txt --tag ghcr.io/Tribler/tribler:v7.14.0-903-gb053617c2 --tag ghcr.io/Tribler/tribler:main --tag ghcr.io/Tribler/tribler:latest --metadata-file /home/runner/work/_temp/docker-actions-toolkit-jld9CF/build-metadata-e938da0d51.json --push .
ERROR: invalid tag "ghcr.io/Tribler/tribler:v7.14.0-903-gb053617c2": repository name must be lowercase

[qstokkink]

It seems like we simply need another step to convert the following tags to lowercase strings:

https://github.com/Tribler/tribler/blob/134fa6469ee48083a8397402da786eb50c88aa11/.github/workflows/build_docker.yml#L48-L50

[qstokkink]

A new error popped up:

 Error: The template is not valid. .github/workflows/build_docker.yml (Line: 45, Col: 11): Unexpected value 'REGISTRY=ghcr.io IMAGE_NAME=Tribler/tribler REF_NAME=main'

[qstokkink]

Oops, this is using the wrong syntax.

REGISTRY=${{ env.REGISTRY }}
IMAGE_NAME=${{ env.IMAGE_NAME }}
REF_NAME=${{ github.ref_name }}

Should be:

REGISTRY: ${{ env.REGISTRY }}
IMAGE_NAME: ${{ env.IMAGE_NAME }}
REF_NAME: ${{ github.ref_name }}