Add REPO_URL in Dockerfile to allow docker builds from contributor repos

[mreso]

Description

When an external contributor creates a PR his branch lives in his own serve fork but our CI tries to load the branch from pytorch/serve when building the docker images.
This PR introduces a new command line option for build_image.sh to set the repo url which we also set in the workflow file for the docker ci using github.repositoryUrl context variable.

#Risk analysis
External PR will still need to be acknowledged by a maintainer and PRs are already running outside docker, so there is no additional risk involved.

Fixes #(issue)

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

Feature/Issue validation/testing

Please describe the Unit or Integration tests that you ran to verify your changes and relevant result summary. Provide instructions so it can be reproduced.
Please also list any relevant details for your test configuration.

• Test A

./build_image.sh -t torchserve:1.0 -b feature/docker_url -repo https://github.com/mreso/serve
[+] Building 250.1s (28/28) FINISHED                                                                                                                                                                                                                                                                                                                       docker:default
 => [internal] load build definition from Dockerfile                                                                                                                                                                                                                                                                                                                 0.0s
 => => transferring dockerfile: 9.72kB                                                                                                                                                                                                                                                                                                                               0.0s
 => [internal] load .dockerignore                                                                                                                                                                                                                                                                                                                                    0.0s
 => => transferring context: 2B                                                                                                                                                                                                                                                                                                                                      0.0s
 => resolve image config for docker.io/docker/dockerfile:experimental                                                                                                                                                                                                                                                                                                0.5s
 => CACHED docker-image://docker.io/docker/dockerfile:experimental@sha256:600e5c62eedff338b3f7a0850beb7c05866e0ef27b2d2e8c02aa468e78496ff5                                                                                                                                                                                                                           0.0s
 => [internal] load build definition from Dockerfile                                                                                                                                                                                                                                                                                                                 0.0s
 => [internal] load .dockerignore                                                                                                                                                                                                                                                                                                                                    0.0s
 => [internal] load metadata for docker.io/library/ubuntu:20.04                                                                                                                                                                                                                                                                                                      0.3s
 => [internal] load build context                                                                                                                                                                                                                                                                                                                                    0.6s
 => => transferring context: 2.40MB                                                                                                                                                                                                                                                                                                                                  0.6s
 => CACHED [production-image 1/9] FROM docker.io/library/ubuntu:20.04@sha256:fa17826afb526a9fc7250e0fbcbfd18d03fe7a54849472f86879d8bf562c629e                                                                                                                                                                                                                        0.0s
 => => resolve docker.io/library/ubuntu:20.04@sha256:fa17826afb526a9fc7250e0fbcbfd18d03fe7a54849472f86879d8bf562c629e                                                                                                                                                                                                                                                0.0s
 => [compile-image  2/11] RUN --mount=type=cache,id=apt-dev,target=/var/cache/apt     apt-get update &&     apt-get upgrade -y &&     apt-get install software-properties-common -y &&     add-apt-repository -y ppa:deadsnakes/ppa &&     apt remove python-pip  python3-pip &&     DEBIAN_FRONTEND=noninteractive apt-get install --no-install-recommends -y      92.7s
 => [compile-image  3/11] RUN python3.9 -m venv /home/venv                                                                                                                                                                                                                                                                                                           2.8s
 => [compile-image  4/11] RUN python -m pip install -U pip setuptools                                                                                                                                                                                                                                                                                                3.3s
 => [compile-image  5/11] RUN export USE_CUDA=1                                                                                                                                                                                                                                                                                                                      0.3s
 => [compile-image  6/11] COPY ./ serve                                                                                                                                                                                                                                                                                                                             63.5s
 => [compile-image  7/11] RUN     if echo "false" | grep -q "false"; then         rm -rf serve;        git clone --recursive https://github.com/mreso/serve -b feature/docker_url;     fi                                                                                                                                                                           25.9s
 => [compile-image  8/11] WORKDIR serve                                                                                                                                                                                                                                                                                                                              0.0s
 => [compile-image  9/11] RUN cp docker/dockerd-entrypoint.sh /usr/local/bin/dockerd-entrypoint.sh                                                                                                                                                                                                                                                                   0.2s
 => [compile-image 10/11] RUN     if echo "ubuntu:20.04" | grep -q "cuda:"; then         if [ "" ]; then             python ./ts_scripts/install_dependencies.py --cuda ;        else             python ./ts_scripts/install_dependencies.py;        fi;     else         python ./ts_scripts/install_dependencies.py;     fi                                      41.5s
 => [compile-image 11/11] RUN     if echo "false" | grep -q "true"; then         python -m pip install -r requirements/developer.txt;        python ts_scripts/install_from_src.py;    elif echo "false" | grep -q "false"; then         python -m pip install --no-cache-dir torchserve torch-model-archiver torch-workflow-archiver;    else         python -m pi  1.6s
 => CACHED [production-image 2/9] RUN --mount=type=cache,target=/var/cache/apt     apt-get update &&     apt-get upgrade -y &&     apt-get install software-properties-common -y &&     add-apt-repository ppa:deadsnakes/ppa -y &&     apt remove python-pip  python3-pip &&     DEBIAN_FRONTEND=noninteractive apt-get install --no-install-recommends -y     pyt  0.0s
 => CACHED [production-image 3/9] RUN useradd -m model-server     && mkdir -p /home/model-server/tmp                                                                                                                                                                                                                                                                 0.0s
 => [production-image 4/9] COPY --chown=model-server --from=compile-image /home/venv /home/venv                                                                                                                                                                                                                                                                      9.4s
 => [production-image 5/9] COPY --from=compile-image /usr/local/bin/dockerd-entrypoint.sh /usr/local/bin/dockerd-entrypoint.sh                                                                                                                                                                                                                                       0.0s
 => [production-image 6/9] RUN chmod +x /usr/local/bin/dockerd-entrypoint.sh     && chown -R model-server /home/model-server                                                                                                                                                                                                                                         0.2s
 => [production-image 7/9] COPY docker/config.properties /home/model-server/config.properties                                                                                                                                                                                                                                                                        0.0s
 => [production-image 8/9] RUN mkdir /home/model-server/model-store && chown -R model-server /home/model-server/model-store                                                                                                                                                                                                                                          0.3s
 => [production-image 9/9] WORKDIR /home/model-server                                                                                                                                                                                                                                                                                                                0.0s
 => exporting to image                                                                                                                                                                                                                                                                                                                                               4.3s
 => => exporting layers                                                                                                                                                                                                                                                                                                                                              4.2s
 => => writing image sha256:9fc95390ef86ecfe819c6aca0c8c9bf1a4ea69c21ca4af77abdf00667923a14d                                                                                                                                                                                                                                                                         0.0s
 => => naming to docker.io/library/torchserve:1.0

Checklist:

• Did you have fun?
• Have you made corresponding changes to the documentation?

[agunapal]

Thanks for fixing this.
LGTM.

Do you think this should be the full url or we can have just the username as the arg ex: mreso

[mreso]

I think full url is good. That enables users to point to internal git repos too.