Add configurable docker entrypoint (#904)

* make docker entrypoint configurable
* add documentation for DOCKER_ENTRYPOINT

Author: pgehring

doc/index.rst

@@ -191,6 +191,7 @@ Note that some of these currently tied only to a single option, but we still lea
 * **DEBUG_BASH** (default: not set): If set with any value (e.g. ``true``), all executed commands that are not printed by default to reduce print space will be printed.
 * **DOCKER_COMMIT** (default: not set): If set, the docker image, which contains the build and test artifacts, will be saved in a Docker image. If unset, the container will not be commited and is removed. The value is used to specify an image name during the ``docker commit`` command. *Note* while this allows you to use the resulting docker image with eg. `docker run -it <DOCKER_COMMIT> /bin/bash`, the main intended use is with the `rerun_ci` feature or subsequent `industrial_ci`runs, which also manages attaching the required volumes etc.
 * **DOCKER_COMMIT_MSG** (default: not set): used to specify a commit during the docker commit command which is triggered by setting ``DOCKER_COMMIT``. If unset and if ``DOCKER_COMMIT`` is set then the commit message will be empty. See more ``DOCKER_COMMIT``.
+* **DOCKER_ENTRYPOINT** (default: not set): Used to specify an entrypoint for the docker image.
 * **DOCKER_IMAGE** (default: not set): Selects a Docker images different from default one. Please note, this disables the handling of ``ROS_REPOSITORY_PATH`` and ``ROS_DISTRO`` as ROS needs already to be installed in the image.
 * **DOCKER_PULL** (default: ``true``): set to false if custom docker image should not be pulled, e.g. if it was created locally
 * **DOCKER_RUN_OPTS** (default: not set): Used to specify additional run options for Docker.

industrial_ci/src/isolation/docker.sh

@@ -18,6 +18,7 @@
 export DOCKER_COMMIT=${DOCKER_COMMIT:-}
 export DOCKER_COMMIT_MSG=${DOCKER_COMMIT_MSG:-}
 export DOCKER_CREDENTIALS=${DOCKER_CREDENTIALS-.docker .gitconfig .ssh .subversion}
+export DOCKER_ENTRYPOINT=${DOCKER_ENTRYPOINT:-}
 export DOCKER_PULL=${DOCKER_PULL:-true}
 export _BUNDLE_ICI=${_BUNDLE_ICI:-false}
 
@@ -104,7 +105,7 @@ function ici_isolate() {
 
   ici_run_cmd_in_docker "${_docker_run_opts[@]}" "${run_opts[@]}" \
                         -t \
-                        --entrypoint '' \
+                        --entrypoint "$DOCKER_ENTRYPOINT" \
                         -w "$TARGET_REPO_PATH" \
                         "$DOCKER_IMAGE" \
                         /bin/bash "$ICI_SRC_PATH/run.sh" "$file" "$@"