docker-run

#!/usr/bin/env bash
set -o errexit -o pipefail
DIR=$(dirname "${0}")
MAIN_DIR=$(readlink -f "${DIR}/..")
if [ -L "${MAIN_DIR}/.git/config" ]; then
    # Support git-new-workdir
    GIT_DIR="$(dirname "$(realpath "${MAIN_DIR}/.git/config")")"
else
    # Support git-worktree
    GIT_DIR="$(cd "${MAIN_DIR}" && git rev-parse --no-flags --git-common-dir)"
fi
if test -z "${IMAGE}" ; then
    # shellcheck disable=SC2016
    IMAGE=$(grep ^image: "${MAIN_DIR}/.gitlab-ci.yml" | \
            sed -e 's,^image: ,,g' | sed -e 's,\$CI_REGISTRY,registry.gitlab.com,g')
fi

declare -a docker_opts=(
    -i
    --rm
    --user "$(id -u):$(id -g)"
    --workdir "$(pwd)"
    --security-opt label=disable
    --network host
)

declare -a mountpoints=(
    "${MAIN_DIR}"
    "$(pwd)"
)

# curl lists (and recognises and uses) other types of *_proxy variables,
# but only those make sense for Buildroot:
for env in all_proxy http_proxy https_proxy ftp_proxy no_proxy; do
    if [ "${!env}" ]; then
        docker_opts+=( --env "${env}" )
        # The lower-case variant takes precedence on the upper-case one
        # (dixit curl)
        continue
    fi
    # http_proxy is only lower-case (dixit curl)
    if [ "${env}" = http_proxy ]; then
        continue
    fi
    # All the others also exist in the upper-case variant
    env="${env^^}"
    if [ "${!env}" ]; then
        docker_opts+=( --env "${env}" )
    fi
done

# Empty GIT_DIR means that we are not in a workdir, *and* git is too old
# to know about worktrees, so we're not in a worktree either. So it means
# we're in the main git working copy, and thus we don't need to mount the
# .git directory.
if [ "${GIT_DIR}" ]; then
    # GIT_DIR in the main working copy (when git supports worktrees) will
    # be just '.git', but 'docker run' needs an absolute path. If it is
    # not absolute, GIT_DIR is relative to MAIN_DIR. If it's an absolute
    # path already (in a wordir), then that's a noop.
    GIT_DIR="$(cd "${MAIN_DIR}"; readlink -e "${GIT_DIR}")"
    mountpoints+=( "${GIT_DIR}" )

    # 'repo' stores .git/objects separately.
    if [ -L "${GIT_DIR}/objects" ]; then
        # GITDIR is already an absolute path, but for symetry
        # with the above, keep the same cd+readlink construct.
        OBJECTS_DIR="$(cd "${MAIN_DIR}"; readlink -e "${GIT_DIR}/objects")"
        mountpoints+=( "${OBJECTS_DIR}" )
    fi
fi

if [ "${BR2_DL_DIR}" ]; then
    mountpoints+=( "${BR2_DL_DIR}" )
    docker_opts+=( --env BR2_DL_DIR )
fi

# shellcheck disable=SC2013 # can't use while-read because of the assignment
for dir in $(printf '%s\n' "${mountpoints[@]}" |LC_ALL=C sort -u); do
    docker_opts+=( --mount "type=bind,src=${dir},dst=${dir}" )
done

if tty -s; then
    docker_opts+=( -t )
fi

exec docker run "${docker_opts[@]}" "${IMAGE}" "${@}"