public-data-api

Exposes datasets stored in S3-compatible object storage with a light-touch API.

• Does not use a database
• Data can be published via data.gov.uk
• Data can be accessed by an API, or downloaded
• Promotes immutable and versioned datasets
• Includes GOV.UK Design System-styled documentation, exposed on the same domain as the API itself
• Department-specific content in the documentation is populated from environment variables
• Low memory usage even for large datasets - responses are streamed to the client
• Data is gzipped and transparently uncompressed by clients when possible
• HTTP Range requests are supported when possible to allow clients to resume interrupted downloads
• The HTTP Content-Length header is returned when possible to allow clients to estimate download time remaining
• HTTP Cookies are not used

Running tests

pip install -r requirements_test.txt  # Only required once
./start-services.sh                   # Only required once
./test_app.sh

Running locally

Most development can be done from tests. However, it can be useful to run the front end of the application locally to work on the documentation. The below results in the documentation being visible at http://localhost:8888/

pip install -r requirements.txt  # Only required once
PORT=8888 \
READONLY_AWS_ACCESS_KEY_ID=any \
READONLY_AWS_SECRET_ACCESS_KEY=any \
AWS_S3_ENDPOINT=http://any/ \
AWS_S3_REGION=any \
APM_SECRET_TOKEN=any \
APM_SERVER_URL=any \
ENVIRONMENT=any \
DOCS_DEPARTMENT_NAME='Department for International Trade' \
DOCS_SERVICE_NAME='Data API' \
DOCS_GITHUB_REPO_URL=https://github.com/uktrade/public-data-api \
    python3 -m app

The S3-compatible storage on your local machine will be visible at http://localhost:9001/. The username and password for the console login are the environment variables MINIO_ACCESS_KEY and MINIO_SECRET_KEY from ./start-services.sh.

Environment variables

Variable	Description and examples
AWS_S3_REGION	The AWS region of the S3 bucket eu-west-2
AWS_S3_ENDPOINT	The URL to the bucket, optionally including a key prefix, and will typically end in a slash. Supports both path and domain-style bucket-access. https://my-bucket.s3-eu-west-2.amazonaws.com/key-prefix/ https://s3-eu-west-2.amazonaws.com/my-bucket/key-prefix/
READONLY_AWS_ACCESS_KEY_ID	The AWS access key ID that has GetObject, and optionally ListBucket, permissions - used by the API
READONLY_AWS_SECRET_ACCESS_KEY	The secret part of the readonly AWS access key
READ_AND_WRITE_AWS_ACCESS_KEY_ID	The AWS access key ID that has write permissions on the S3 bucket (for the csv-generating worker)
READ_AND_WRITE_AWS_SECRET_ACCESS_KEY	The secret part of the read+write AWS access key
ENVIRONMENT	The current environment where the application is running develop
PARQUET_ROW_GROUP_SIZE	The maximum number of rows Parquet row group - optional with a default of 131072
GA_ENDPOINT (deprecated)	The endpoint to send analytics info to
GA_TRACKING_ID (deprecated)	The unique identifier for the google analytics property
GA4_API_SECRET	The API secret for Google Analytics 4 (GA4)
GA4_MEASUREMENT_ID	The measurement ID for Google Analytics 4 (GA4)

Environment variables used for serving API documentation.

Variable	Description and examples
DOCS_DEPARTMENT_NAME	The name of the department the data is hosted by A Government Department
DOCS_SERVICE_NAME	The name of this service Data API
DOCS_GITHUB_REPO_URL	The URL for this github repository https://github.com/uktrade/public-data-api
DOCS_SECURITY_EMAIL	The email address security vulnerabilities should be reported to security@example.com

The below environment variables are also used, but typically populated by the hosting environment.

Variable	Description and examples
PORT	The port for the application to listen on 8080
GIT_COMMIT	The git commit ID to show what version of the code is running c79c3d630152b42b98e97b73552e0bdc7b54ae51

Permissions and 404s

If the AWS user has the ListBucket permission, 404s are proxied through to the user to aid debugging.

Shutdown

On SIGTERM any in-progress requests will complete before the process exits.

Worker health

A basic CLI is included to check the health of the backend worker that converts between data formats.

python -m app_heartbeat

A zero exit codes means the worker is healthy, otherwise the worker is not healthy.