Installation: lookit-api (Django project)¶
lookit-api is the codebase for Experimenter and Lookit, excluding the actual
studies themselves. Any functionality you see as a researcher or a
participant (e.g., signing up, adding a child, editing or deploying a
study, downloading data) is part of the
This project is built using Django and PostgreSQL. (The studies
themselves use Ember.js; see Ember portion of codebase,
It was initially developed by the Center for Open Science.
If you install only the
lookit-api project locally, you will be able
to edit any functionality that does not require actual study
participation. For instance, you could contribute an improvement to how
studies are displayed to participants or create a new CSV format for
downloading data as a researcher.
These instructions are for Mac OS. Installing on another OS? Please consider documenting the exact steps you take and submitting a PR to the lookit-api repo to update the documentation! For notes on Linux installation, there may be helpful information in a previous version of invoke tasks.py.
This is the software you will need to have installed to run lookit-api locally.
If you haven’t already, install Brew and install Graphviz:
brew install graphviz
You will need to have Docker installed and running.
Install and start rabbitmq via docker:
docker run -d --name lookit-rabbit --env-file .env -p 5672:5672 rabbitmq:3.8.16-management-alpine docker cp ./rabbitmq.sh lookit-rabbit:/rabbitmq.sh docker exec -it lookit-rabbit /bin/sh -c "sh /rabbitmq.sh"
Create a Postgres database using the following command:
docker run --name lookit-postgres -d -e POSTGRES_HOST_AUTH_METHOD="trust" -e POSTGRES_DB="lookit" -p 5432:5432 postgres:9.6
To help with installing a specific version of python, we’ll need to install asdf.
Add Python plugin using the following command. Here’s documentation to help with errors:
asdf plugin-add python
Clone the lookit-api repo:
git clone https://github.com/lookit/lookit-api.git
At the root of the project, install the version of python required by this project; ASDF will automatically detect that from a .tool-versions file. The asdf Python plugin docs can help install older versions of python:
If using macOS 11, you will need to use the patch provided by asdf to install.
Install Python libraries:
If Poetry has trouble finding the version of Python installed by ASDF, double check that asdf.sh has been added to .bash_profile and the shell restarted as described in the asdf installation directions.
Use invoke to run setup:
poetry run invoke setup
This will create a local .env file with environment variables for local development, run the Django application’s database migrations (“catching up” on changes to the database structure), set up rabbitmq with queues for various task types, and create local SSL certificates. If you’re curious about what exactly is happening during this step, or run into any problems, you can reference the file tasks.py.
Create a superuser by running:
poetry run ./manage.py createsuperuser
Now you should be ready for anything. Going forward, you can run the server using the directions below.
Running the server¶
To run the Lookit server locally, run:
poetry run invoke server
Now you can go to http://localhost:8000 to see your local Lookit server! You should be able to log in using the superuser credentials you created during setup.
To view the HTTPS version of the local development add the
https argument to the above command:
poetry run invoke server --https
If you are not working extensively with lookit-api - i.e., if you just want to make some new frames - you do not need to run celery, rabbitmq, or docker. For more information about these services and how they interact, please see the Contributing guidelines.
You should already have a rabbitmq server installed and running. You can check this by:
docker ps -f name=lookit-rabbit
If rabbitmq is not running, you can start it using:
docker start lookit-rabbit
Then use the invoke command to start the celery worker:
poetry run invoke celery-service
You can create participant and researcher accounts through the regular signup flow on your local instance. To access Experimenter you will need to add two-factor authentication to your account following the prompts. In order to access the admin interface (https://localhost:8000/__CTRL__), which provides a convenient way to access and edit records, you will need to log in using the superuser you created earlier using manage.py.
This project includes an incoming webhook handler for an event generated
by the Pipe video recording service used by ember-lookit-frameplayer when video is transferred to our S3
storage. This requires a webhook key for authentication. It can be
generated via our Pipe account and, for local testing, stored in
Pipe needs to be told where to send the webhook. First, you need to expose your local /exp/renamevideo hook. You can use Ngrok to generate a public URL for your local instance during testing:
ngrok http https://localhost:8000
Then, based on the the assigned URL, you will need to manually edit the webhook on the
dev environment of Pipe to send the
video_copied_s3 event to (for example)
During installation, you may see the following:
psql: FATAL: role "postgres" does not exist
To fix, run something like the following from your home directory:
$../../../usr/local/Cellar/postgresql/9.6.3/bin/createuser -s postgres
If your version of postgres is different than 9.6.3, replace with the correct version above. Running this command should be a one-time thing.
You might also have issues with the installation of
running install Trying pkg-config Package libcgraph was not found in the pkg-config search path. Perhaps you should add the directory containing `libcgraph.pc' to the PKG_CONFIG_PATH environment variable No package 'libcgraph' found
pygraphviz/graphviz_wrap.c:2954:10: fatal error: 'graphviz/cgraph.h' file not found #include "graphviz/cgraph.h" ^ 1 error generated. error: command 'clang' failed with exit status 1
To fix, try running something like:
$ brew install graphviz $ pip install --install-option="--include-path=/usr/local/include" --install-option="--library-path=/usr/local/lib" pygraphviz
Then re-run setup.