dp-legacy-cache-api

REST API for managing cache control information for pages within the legacy CMS. dp-legacy-cache-api is called by:

• dp-legacy-cache-proxy to read the release time for a particular item of content (Web subnet/ read-only mode)
• Zebedee to set the right cache time for content based on publish notifications (Publishing subnet)

The API talks to DocumentDB in the environment (or MongoDB locally) in the cachetimes collection.

Database Fields	Description
ID	MD5 hash representing the unique identifier of the page's path.
Path	URI indicating the location of the published page
Next Release Time	Scheduled time for the next update in ISO-8601 format
Collection ID	Utilised for organising and filtering cache time entries

Getting started

• Ensure Docker is installed on your local machine. Installation steps can be found here.
• Run docker run --name mongo-test -p 27017:27017 -e MONGO_INITDB_DATABASE=cache -v $(pwd)/mongo-init:/docker-entrypoint-initdb.d -d mongo.
  • This command launches a MongoDB container named mongo-test, maps port 27017 from the host to the container, sets cache as the default database, runs initialization scripts (located in the mongo-init directory), and operates in the background.
• Run make debug to run the application on http://localhost:29100.
• By default, the write (PUT) endpoint is disabled. To be able to create or update resources, please follow these steps:
  • Run Zebedee.
  • Run IS_PUBLISHING=true make debug. This will make the PUT endpoint available.
  • Send a valid request to the PUT endpoint. You'll need to set the Bearer token (the Authorization header's value should be Bearer your-token-here).
    • For local usage, you can use the Service Auth Token specified in the DP's install guide.
    • For Sandbox/Production usage (or to generate a different token), please follow this guide.
• Run make help to see a full list of make targets.

Dependencies

• No further dependencies other than those defined in go.mod

Tools

To run some of our tests you will need additional tooling:

Audit

We use dis-vulncheck to do auditing, which you will need to install.

Linting

We use v2 of golangci-lint, which you will need to install.

Configuration

Environment variable	Default	Description
BIND_ADDR	:29100	The host and port to bind to
MONGODB_BIND_ADDR	localhost:27017	The MongoDB bind address
MONGODB_USERNAME		The MongoDB Username
MONGODB_PASSWORD		The MongoDB Password
MONGODB_DATABASE	cache	The MongoDB database
MONGODB_COLLECTIONS	CacheTimesCollection:cachetimes	The MongoDB collections
MONGODB_REPLICA_SET		The name of the MongoDB replica set
MONGODB_ENABLE_READ_CONCERN	false	Switch to use (or not) majority read concern
MONGODB_ENABLE_WRITE_CONCERN	true	Switch to use (or not) majority write concern
MONGODB_CONNECT_TIMEOUT	5s	The timeout when connecting to MongoDB (time.Duration format)
MONGODB_QUERY_TIMEOUT	15s	The timeout for querying MongoDB (time.Duration format)
MONGODB_IS_SSL	false	Switch to use (or not) TLS when connecting to mongodb
GRACEFUL_SHUTDOWN_TIMEOUT	5s	The graceful shutdown timeout in seconds (time.Duration format)
HEALTHCHECK_INTERVAL	30s	Time between self-healthchecks (time.Duration format)
HEALTHCHECK_CRITICAL_TIMEOUT	90s	Time to wait until an unhealthy dependent propagates its state to make this app unhealthy (time.Duration format)
IS_PUBLISHING	false	Determines if the instance is in publishing or not
ZEBEDEE_URL	http://localhost:8082	Zebedee host address and port for authentication

Auto-Deployment of secrets

Functionality has been added to the nomad plan so that when the secrets are deployed to Vault, this will automatically cause Nomad to trigger a redeployment of the application to pick up the new secrets. Please note that this functionality does not appear to work with the current nomad/vault versions, but if these are upgraded it may then become functional.

License

Copyright © 2024, Office for National Statistics (https://www.ons.gov.uk)

Released under MIT license, see LICENSE for details.