Make start.sh the entrypoint

Closes #1528

Author: manics

docs/using/common.md

@@ -225,21 +225,17 @@ docker run -it --rm \
 
 ### `start.sh`
 
-The `start-notebook.py` script inherits most of its option handling capability from a more generic `start.sh` script.
-The `start.sh` script supports all the features described above but allows you to specify an arbitrary command to execute.
+Most of the configuration options in the `start-notebook.py` script are handled by an internal `start.sh` script that automatically runs before the command provided to the container
+(it's set as the container entrypoint).
+This allows you to specify an arbitrary command that takes advantage of all these features.
 For example, to run the text-based `ipython` console in a container, do the following:
 
 ```bash
-docker run -it --rm quay.io/jupyter/base-notebook start.sh ipython
+docker run -it --rm quay.io/jupyter/base-notebook ipython
 ```
 
 This script is handy when you derive a new Dockerfile from this image and install additional Jupyter applications with subcommands like `jupyter console`, `jupyter kernelgateway`, etc.
 
-### Others
-
-You can bypass the provided scripts and specify an arbitrary start command.
-If you do, keep in mind that features, supported by the `start.sh` script and its kin, will not function (e.g., `GRANT_SUDO`).
-
 ## Conda Environments
 
 The default Python 3.x [Conda environment](https://conda.io/projects/conda/en/latest/user-guide/concepts/environments.html) resides in `/opt/conda`.

docs/using/selecting.md

@@ -34,8 +34,7 @@ It contains:
   - [mamba](https://github.com/mamba-org/mamba): "reimplementation of the conda package manager in C++". We use this package manager by default when installing packages.
 - Unprivileged user `jovyan` (`uid=1000`, configurable, [see options in the common features section](./common.md) of this documentation) in group `users` (`gid=100`)
   with ownership over the `/home/jovyan` and `/opt/conda` paths
-- `tini` as the container entry point
-- A `start.sh` script as the default command - useful for running alternative commands in the container as applications are added (e.g. `ipython`, `jupyter kernelgateway`, `jupyter lab`)
+- `tini` and a `start.sh` script as the container entry point - useful for running alternative commands in the container as applications are added (e.g. `ipython`, `jupyter kernelgateway`, `jupyter lab`)
 - A `run-hooks.sh` script, which can source/run files in a given directory
 - Options for a passwordless sudo
 - Common system libraries like `bzip2`, `ca-certificates`, `locales`

images/base-notebook/start-notebook.py

@@ -14,8 +14,8 @@
     os.execvp(command[0], command)
 
 
-# Wrap everything in start.sh, no matter what
-command = ["/usr/local/bin/start.sh"]
+# Entrypoint is start.sh
+command = []
 
 # If we want to survive restarts, tell that to start.sh
 if os.environ.get("RESTARTABLE") == "yes":

images/base-notebook/start-singleuser.py

@@ -5,7 +5,8 @@
 import shlex
 import sys
 
-command = ["/usr/local/bin/start.sh", "jupyterhub-singleuser"]
+# Entrypoint is start.sh
+command = ["jupyterhub-singleuser"]
 
 # set default ip to 0.0.0.0
 if "--ip=" not in os.environ.get("NOTEBOOK_ARGS", ""):

images/docker-stacks-foundation/Dockerfile

@@ -124,8 +124,7 @@ RUN set -x && \
     fix-permissions "/home/${NB_USER}"
 
 # Configure container startup
-ENTRYPOINT ["tini", "-g", "--"]
-CMD ["start.sh"]
+ENTRYPOINT ["tini", "-g", "--", "start.sh"]
 
 # Copy local files as late as possible to avoid cache busting
 COPY run-hooks.sh start.sh /usr/local/bin/

images/docker-stacks-foundation/start.sh

@@ -34,6 +34,17 @@ else
     cmd=( "$@" )
 fi
 
+# Backwards compatibility: start.sh is executed by default in ENTRYPOINT so
+# should no longer be specified in CMD
+if [ "${_START_SH_EXECUTED}" = "1" ]; then
+    _log "WARNING: start.sh is the default ENTRYPOINT, do not include it in CMD"
+    _log "Executing the command:" "${cmd[@]}"
+    exec "${cmd[@]}"
+else
+    export _START_SH_EXECUTED=1
+fi
+
+
 # NOTE: This hook will run as the user the container was started with!
 # shellcheck disable=SC1091
 source /usr/local/bin/run-hooks.sh /usr/local/bin/start-notebook.d

tests/all-spark-notebook/test_spark_notebooks.py

@@ -33,7 +33,7 @@ def test_nbconvert(container: TrackedContainer, test_file: str) -> None:
         timeout=60,
         volumes={str(host_data_dir): {"bind": cont_data_dir, "mode": "ro"}},
         tty=True,
-        command=["start.sh", "bash", "-c", command],
+        command=["bash", "-c", command],
     )
 
     expected_file = f"{output_dir}/{test_file}.md"

tests/base-notebook/test_container_options.py

@@ -35,7 +35,7 @@ def test_nb_user_change(container: TrackedContainer) -> None:
         tty=True,
         user="root",
         environment=[f"NB_USER={nb_user}", "CHOWN_HOME=yes"],
-        command=["start.sh", "bash", "-c", "sleep infinity"],
+        command=["bash", "-c", "sleep infinity"],
     )
 
     # Give the chown time to complete.

tests/base-notebook/test_pandoc.py

@@ -12,6 +12,6 @@ def test_pandoc(container: TrackedContainer) -> None:
     logs = container.run_and_wait(
         timeout=10,
         tty=True,
-        command=["start.sh", "bash", "-c", 'echo "**BOLD**" | pandoc'],
+        command=["bash", "-c", 'echo "**BOLD**" | pandoc'],
     )
     assert "<p><strong>BOLD</strong></p>" in logs

tests/base-notebook/test_start_container.py

@@ -76,10 +76,7 @@ def test_tini_entrypoint(
     https://superuser.com/questions/632979/if-i-know-the-pid-number-of-a-process-how-can-i-get-its-name
     """
     LOGGER.info(f"Test that {command} is launched as PID {pid} ...")
-    running_container = container.run_detached(
-        tty=True,
-        command=["start.sh"],
-    )
+    running_container = container.run_detached(tty=True)
     # Select the PID 1 and get the corresponding command
     cmd = running_container.exec_run(f"ps -p {pid} -o comm=")
     output = cmd.output.decode("utf-8").strip("\n")