Setting up Development Environment#

The easiest & safest way to develop & test TLJH is with Docker.

Install Docker Community Edition by following the instructions on their website.
Clone the git repo (or your fork of it).

Build a docker image that has a functional systemd in it.

docker build -t tljh-systemd . -f integration-tests/Dockerfile

Run a docker container with the image in the background, while bind mounting your TLJH repository under /srv/src.

docker run \
  --privileged \
  --detach \
  --name=tljh-dev \
  --publish 12000:80 \
  --mount type=bind,source="$(pwd)",target=/srv/src \
  tljh-systemd

Get a shell inside the running docker container.
```
docker exec -it tljh-dev /bin/bash
```
Run the bootstrapper from inside the container (see step above): The container image is already set up to default to a dev install, so it’ll install from your local repo rather than from github.
```
python3 /srv/src/bootstrap/bootstrap.py --admin admin
```
Or, if you would like to setup the admin’s password during install, you can use this command (replace “admin” with the desired admin username and “password” with the desired admin password):
```
python3 /srv/src/bootstrap/bootstrap.py --admin admin:password
```
The primary hub environment will also be in your PATH already for convenience.
You should be able to access the JupyterHub from your browser now at http://localhost:12000. Congratulations, you are set up to develop TLJH!
Make some changes to the repository. You can test easily depending on what you changed.
- If you changed the bootstrap/bootstrap.py script or any of its dependencies, you can test it by running python3 /srv/src/bootstrap/bootstrap.py.
- If you changed the tljh/installer.py code (or any of its dependencies), you can test it by running python3 -m tljh.installer.
- If you changed tljh/jupyterhub_config.py, tljh/configurer.py, /opt/tljh/config/ or any of their dependencies, you only need to restart jupyterhub for them to take effect. tljh-config reload hub should do that.

Looking at Logs has information on looking at various logs in the container to debug issues you might have.