This is a user-agent value store, a take on a key-value store where all keys are the user-agent of the HTTP client accessing the API. One string item is stored per user-agent. As many user-agents are allowed to store an item as will fit in memory. Storage is ephemeral and just for kicks :)
Build & Run:
docker build -t useragent-value-store-api . && docker run -dp 80:80 --name useragent-value-store-api useragent-value-store-api
Example use:
$ curl -X POST http://localhost/v1/value -d test1
{"userAgent":"curl/8.7.1","value":"test1"}
$ curl -X GET http://localhost/v1/value
{"userAgent":"curl/8.7.1","value":"test1"}
$ curl -X GET http://localhost
{"numUserAgents:":1,"userAgent":"curl/8.7.1"}
$ curl -X DELETE http://localhost/v1/value