Open Targets REST API

Contributing

Testing locally

clone repository
cd flask-rest-api
pip install -r requirements.txt (possiby in a virtualenv)
python manage.py runserver runs the dev server. Do not use in production.
python manage.py runserver -p 8123 runs the dev server on port 8123
python manage.py test runs the test suites.

By default the rest api is available at http://localhost:5000

Swagger YAML documentation is exposed at http://localhost:5000/api/docs/swagger.yaml

Elasticsearch backend

It expects to have an Elasticsearch instance on http://localhost:9200. Alternative configurations are available using the OPENTARGETS_API_CONFIG environment variable Valid OPENTARGETS_API_CONFIG options:

development: default option
staging: to be used in staging area
production: to be used in production area
testing: to be used for tests

see the config.py file for details

Custom data sources

Custom data sources can be specified via and environment variable, assuming that the relevant indices exist in the Elasticsearch instance to which the API is pointing. The environment variable must be named CUSTOM_DATASOURCE, and expressed in the form new_data_source_name:data_type, e.g. export CUSTOM_DATASOURCE=genomics_england_tiering:genetic_association Multiple custom data sources of the same type can be passed as a comma-separated list.

debugging

We never run flask directly. Even in the manage.py script we spawn off a WSGIServer(). Hence Flask debug mode does not work out of the box.

To debug while running flask locally (ie. using python manage.py runserver) one can pass API_DEBUG=True instead than the traditional FLASK_DEBUG=True environment variable to turn on the Flask debugger and increase the level of logging. This works by wrapping the app in werkzeug middleware. More details on http://stackoverflow.com/questions/10364854/flask-debug-true-does-not-work-when-going-through-uwsgi

However this will not work when the app is run by uwsgi, as it is in the docker container and in production. This is intentional since DEBUG mode there would allow code injection.

Docker Container

Build

You can build the container from source:

docker build -t rest_api:local .

or use our docker containers on quay.io ()

Running with Docker on HTTP

Pre-requisites

The REST API Docker image URL on Quay.io
The correct image tag for the Open Targets release you're running (e.g. 19.02.1)
The URL of the Elasticsearch server
The data version, e.g. 19.02. If you're using the data pipeline, this must match the common prefix of the Elasticsearch index names in the ‘mrtarget.es.yml’ file of the pipeline.

docker run -p 8080:80 \
-e "ELASTICSEARCH_URL=http://localhost:9200" \
-e "OPENTARGETS_DATA_VERSION=19.02" \
--privileged quay.io/opentargets/rest_api:19.02.1

Running with Docker on HTTPS

Pre-requisites

As above, plus:

Appropriate SSL certificates in ./nginx_ssl called server.crt and server.key

Naming the certificate and key files server.crt and server.key means that you don't need to edit nginx.template.

Note that this example presents the REST API on port 7443; customise the command as required.

docker run -p 7443:443 \
-e "ELASTICSEARCH_URL=http://localhost:9200" \
-e "OPENTARGETS_DATA_VERSION=19.02" \
-v "$(pwd)"/nginx_ssl:/etc/ssl/nginx \
--privileged quay.io/opentargets/rest_api:19.02.1

If there are issues with the certificate not being presented, ensure that the volume mapping for ./nginx_ssl is correct.

For more options available when using docker run you can take a look at the ansible role that we use to spin a single instance of our frontend stack.

Check that it's running

Supposing the container runs in localhost and expose port 8080, Swagger UI is available at: http://localhost:8080/v3/platform/docs

You can ping the API with curl localhost:8080/v3/platform/public/utils/ping

You can check that is talking to your instance of Elasticsearch by using the /platform/latest/public/utils/stats method.

Why privileged mode?

The REST API container runs 3 services talking and launching each other: nginx, uwsgi and the actual flask app. nginx and uwsgi talks trough a binary protocol in a unix socket. it is very efficient, but by default sockets have a small queue, so if nginx is under heavy load and sends too many requests to uwsgi they get rejected by the socket and raise an error. to increase the size of the queue unfortunately you need root privileges. at the moment we think that the performance gain is worth the privileged mode. but it strongly depends on the environment you deploy the container into

Proxy settings

The REST API container also serves as the default proxy for all external API calls made by the Open Targets frontend webapp. To add more domains to the proxy configuration, add them to docker/nginx-custom.conf.

Copyright

This software was developed as part of the Open Targets project. For more information please see: http://www.opentargets.org

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.