Add proxy configuration

[brcourt]

cfn submit doesn't seem to work if a proxy is configured. Adding use_config_proxy to the _docker_build method in codegen.py shown below seems to resolve the issue.

@classmethod
def _docker_build(cls, external_path):
    cls._check_for_support_lib_sdist(external_path)

    internal_path = PurePosixPath("/project")
    command = " ".join(cls._make_pip_command(internal_path))
    LOG.debug("command is '%s'", command)

    volumes = {str(external_path): {"bind": str(internal_path), "mode": "rw"}}
    image = f"lambci/lambda:build-{cls.RUNTIME}"
    LOG.warning(
        "Starting Docker build. This may take several minutes if the "
        "image '%s' needs to be pulled first.",
        image,
    )
    docker_client = docker.from_env()
    try:
        logs = docker_client.containers.run(
            image=image,
            command=command,
            auto_remove=True,
            volumes=volumes,
            stream=True,
            use_config_proxy=True   #<=== use proxy configuration if specified in config.json
        )

[ammokhov]

cfn submit doesn't seem to work if a proxy is configured. Adding use_config_proxy to the _docker_build method in codegen.py shown below seems to resolve the issue.

@classmethod
def _docker_build(cls, external_path):
    cls._check_for_support_lib_sdist(external_path)

    internal_path = PurePosixPath("/project")
    command = " ".join(cls._make_pip_command(internal_path))
    LOG.debug("command is '%s'", command)

    volumes = {str(external_path): {"bind": str(internal_path), "mode": "rw"}}
    image = f"lambci/lambda:build-{cls.RUNTIME}"
    LOG.warning(
        "Starting Docker build. This may take several minutes if the "
        "image '%s' needs to be pulled first.",
        image,
    )
    docker_client = docker.from_env()
    try:
        logs = docker_client.containers.run(
            image=image,
            command=command,
            auto_remove=True,
            volumes=volumes,
            stream=True,
            use_config_proxy=True   #<=== use proxy configuration if specified in config.json
        )

we would be happy to take a PR that addresses it