GDS API Adapters

A set of API adapters to work with the GDS APIs.

Example usage:


Example adapters for frequently used applications:


Each HTTP request can be logged as JSON. Example:


By default we log to a NullLogger since we don't want to pollute your test results or logs. To log output you'll want to set GdsApi::Base.logger to something that actually logs:

GdsApi::Base.logger ="/path/to/file.log")

Setting the timeout

By default the JsonClient timeout is set to 4 seconds. If this is exceeded a GdsApi::TimedOutException will be raised. You can override this by doing: that uses the adapter with:

adapter = GdsApi.publishing_api(timeout: <number_of_seconds>)

In most cases, there is an upper-limit of 30 seconds imposed by the app server or Nginx. If your requests are taking this long, you should probably be looking into other options to lower the response time.

Middleware for request tracing

We set a unique header at the cache level called Govuk-Request-Id, and also set a header called Govuk-Original-Url to identify the original URL requested. If apps make API requests in order to serve a user's request, they should pass on these headers, so that requests can be traced across the entire GOV.UK stack.

The GdsApi::GovukHeaderSniffer middleware takes care of this. This gem contains a railtie that configures this middleware for Rails apps without extra effort. Other Rack-based apps should opt-in by adding these lines to your

use GdsApi::GovukHeaderSniffer, 'HTTP_GOVUK_REQUEST_ID'
use GdsApi::GovukHeaderSniffer, 'HTTP_GOVUK_ORIGINAL_URL'

Middleware for identifying authenticated users

Applications can make use of user-based identification for additional authorisation when making API requests. Any application that is using gds-sso for authentication can set an additional header called 'X-Govuk-Authenticated-User' to identify the currently authenticated user ID. This will automatically be picked up by the GdsApi::GovukHeaderSniffer middleware in Rails applications and sent with API requests so that the downstream service can optionally use the identifier to perform authorisation on the request. This will be used by content-store as a mechanism to only return access-limited content to authenticated and authorised users.

Test Helpers

There are also test helpers for stubbing various requests in other apps.

See all the test helpers in lib/gds_api/test_helpers.

Pact Verification During CI

During the CI test suite, Jenkins downloads and runs the pact:verify tasks for each provider app. It's run directly on the Jenkins machine rather than in docker containers for each app. For this reason the email-alert-api app requires a specific setup on the CI machine - on db creation it copies the database from the template1 db (this is the usual PG behaviour, but for some reason rails needs to be told to do this explicitly). This template1 db has to have the uuid-ossp extension installed by superuser, because the jenkins user that CI runs under cannot create this extension. If this test stops working with errors like:

Caused by:
PG::InsufficientPrivilege: ERROR:  permission denied to create extension "uuid-ossp"
HINT:  Must be superuser to create this extension.

...the template may have been deleted or changed. Log in to the relevant CI agent and run:

> sudo -u postgres psql -d template1

Then at the PSQL command line:

template1=# CREATE EXTENSION IF NOT EXISTS "uuid-ossp";


Released under the MIT Licence, a copy of which can be found in the file LICENCE.