chs-streaming-api-cache

README

chs-streaming-api-cache

Contents

The Companies House Streaming Platform Cache consumes offsets from the Streaming Platform Backend service and caches the entries in Redis, and pushes these to connected users as an event stream.

Requirements

The following services and applications are required to build and/or run chs-streaming-api-cache:

• AWS ECR
• Docker
• Redis
• Companies House Streaming Platform Backend (chs-streaming-api-backend)

You will need an HTTP client that supports server-sent events (e.g. cURL) to connect to the service and receive published offsets.

Building and Running Locally

1. Login to AWS ECR.
2. Build the project by running docker build from the project directory.
3. Run the Docker image that has been built by running docker run IMAGE_ID from the command line, ensuring values have been specified for the environment variables (see Configuration) and that port 6001 is exposed.
4. Send a GET request using your HTTP client to /filings. A connection should be established and any offsets published to the stream-filing-history topic should appear in the response body. The offsets should also be cached in Redis for other consumers.

Configuration

Variable	Description	Example	Mandatory
REDIS_URL	The URL of the Redis cache	redis:6379	yes
STREAMING_BACKEND_URL	The URL of the CH Streaming Backend service	http://chs-streaming-api-backend:6000	yes
REDIS_POOL_SIZE	The number of connections in a Redis connection pool	10	yes
CACHE_EXPIRY_IN_SECONDS	The number of seconds before a offset cache entry expires	3600	yes
STREAM_BACKEND_FILINGS_PATH	The backend endpoint to stream filing history offsets	/streaming-api-backend/filings	yes
STREAM_BACKEND_COMPANIES_PATH	The backend endpoint to stream filing history offsets	/streaming-api-backend/companies?timepoint=2	yes
STREAM_BACKEND_INSOLVENCY_PATH	The backend endpoint to stream company insolvency offsets	/streaming-api-backend/insolvency-cases	yes
STREAM_BACKEND_CHARGES_PATH	The backend endpoint to stream company charges offsets	/streaming-api-backend/charges	yes
STREAM_BACKEND_OFFICERS_PATH	The backend endpoint to stream officer appointments offsets	/streaming-api-backend/officers	yes
STREAM_BACKEND_PSCS_PATH	The backend endpoint to stream PSC offsets	/streaming-api-backend/persons-with-significant-control	yes
CHS_API_KEY	The key used for basic authenication in http requests	abc123	yes