SRE take-home test - LADIT

Code

it has been some time since I wrote Go, so I welcome the occasion
for the purpose of simplicity, state will only reside in-memory, neither a backing service to manage the state outside of the service nor an interface to such service is being implemented
due to some time constraints, it was decided to pull in dependencies for all the heavy lifting
- API server
- configuration
- testing
CIDR is used as identifier (not for instance the combination of CIDR and TTL), which means posting the same CIDR will have no effect
at first, I wanted to decouple blocklist and store to ease adaption for a backing service to manage state externally, but then I realized that it would mean to write tests for an additional abstraction layer which is not needed for now
although being required, it was decided to not include the IP blocking middleware in the /healthcheck endpoint, because if a certain CIDR would be set to block, it might render the service unheathy from outer context's perspective that is tasked to keep the service up and running, e.g. a kubelet. Alternatively, one could just exclude private IPs (IP.IsPrivate()) or introduce a (configurable) list of unblockable IP ranges.
adding a new CIDR on /block results in 201 Created instead of 200 OK as requested
additional time constraints resulted in tests only to verify the HTTP API behaviour, instead of integration tests (e.g. for main.go) and unit tests (e.g. for blocking/blocklist.go)

used recommended Terraform provider: https://registry.terraform.io/providers/kreuzwerker/docker
located in ./terraform
no Terraform state management whatsoever, since everything is (currently) applied locally