cellxgene-gateway/Readme.md

Overview

Cellxgene Gateway allows you to use the Cellxgene Server provided by the Chan Zuckerberg Institute (https://github.com/chanzuckerberg/cellxgene) with multiple datasets. It displays an index of available h5ad (anndata) files. When a user clicks on a file name, it launches a Cellxgene Server instance that loads that particular data file and once it is available proxies requests to that server.

Running locally

Prequisites

1. This project requires python 3.6 or higher. Please check your version with

$ python --version

2. It is also a good idea to set up a venv

python -m venv .cellxgene-gateway
source .cellxgene-gateway/bin/activate # type `deactivate` to deactivate the venv

Install cellxgene-gateway

Option 1: Pip Install from Github

pip install git+https://github.com/Novartis/cellxgene-gateway

Option 2: Install from PyPI

# NOT YET DONE, COMING! STAY TUNED

Running cellxgene gateway

1. Prepare a folder with .h5ad files, for example

mkdir ../cellxgene_data
wget https://github.com/chanzuckerberg/cellxgene/raw/master/example-dataset/pbmc3k.h5ad -O ../cellxgene_data/pbmc3k.h5ad

2. Set your environment variables correctly:

export CELLXGENE_DATA=../cellxgene_data  # change this directory if you put data in a different place.
export CELLXGENE_LOCATION=`which cellxgene`
export GATEWAY_HOST=localhost:5005
export GATEWAY_PROTOCOL=http
export GATEWAY_IP=127.0.0.1

3. Now, execute the cellxgene gateway:

cellxgene-gateway

Here's what the environment variables mean:

• CELLXGENE_LOCATION - the location of the cellxgene executable, e.g. ~/anaconda2/envs/cellxgene/bin/cellxgene
• CELLXGENE_DATA - a directory that can contain subdirectories with .h5ad data files, without trailing slash, e.g. /mnt/cellxgene_data
• GATEWAY_HOST - the hostname and port that the gateway will run on, typically localhost:5005 if running locally
• GATEWAY_PROTOCOL - typically http when running locally, can be https when deployed if the gateway is behind a load balancer or reverse proxy.

The defaults should be fine if you set up a venv and cellxgene_data folder as above.

Customization

The current paradigm for customization is to modify files during a build or deployment phase:

• To modify CSS or JS on particular gateway pages, overwrite or append to the templates
• To add script tags such as for user analytics to all pages, overwrite the extra_scripts.py file.
  • these scripts will also be run on the pages served by cellxgene server via the --scripts parameter
  • See https://github.com/chanzuckerberg/cellxgene/pull/680 for details on --scripts parameter

Currently we use a build.sh that copies the gateway to a "build" directory before modifying with sed and the like.

Development

Developer Install

If you want to develop the code, you will need to clone the repo. Make sure you have the prequesite listed above, then:

1. Clone the repo

    git clone https://github.com/Novartis/cellxgene-gateway.git
    cd cellxgene-gateway

2. Install requirements with

pip install -r requirements.txt

3. Install the gateway in developer mode

python setup.py develop

For convenience, the code repo includes a run.sh.example shell script to run the gateway.

Running Linters

pip install isort flake8 black

isort -rc .
flake8 .
black -l 79 .

Getting Help

If you need help for any reason, please make a github ticket. One of the contributors should help you out.

Contributors

• Niket Patel - https://github.com/NiketPatel9
• Alok Saldanha - https://github.com/alokito
• Yohann Potier - https://github.com/ypotier