Tannin Backend Home Assignment

General Info

You should not encounter any problems in the setup phase. If that happens - please let us know.

In general, please reach out if you have questions or concerns before and during the assignment.

When you're done, you can either:

1. Email your repo.

2. Setup a private GitHub repo and invite @hodbn and @itaischwartz as collaborators.

Rules

1. The assignment should take up to five hours. Code is never perfect :)

2. Don’t use any more third-party libraries (i.e., your go.mod must not change).

3. Don’t complete the implementation of the service’s logic (no need to implement DELETE, etc).

4. The code you add should be production-grade, it’s your judgment what that means.

Objective

This is an existing pet store service based on the pet store API with a simple monitoring stack of Prometheus and Grafana.

Add a requests-per-second metric to the server, partitioned by the route (bonus: also partition by HTTP method).

Note: Your code can assume the usage of the gorilla/mux framework.

Setup

foo@bar:~$ docker compose up --build
...
foo@bar:~$ # docker compose down -v
...

The services will be available on:

• petstore: http://localhost:9900/api

• prometheus: http://localhost:9901/

• grafana: http://localhost:9902/

Additionally, this setup will run a traffic generator against petstore with:

• pet creations: ~1 rps

• pet retrievals: ~5 rps

You can see the predefined dashboard on grafana (default creds are admin:admin). Before you complete the assignment it'll look like this:

After you're done, it should look like this:

Standalone

You can build the service binary and run it with

foo@bar:~$ make run
CGO_ENABLED=0 go build -v -o server cmd/app/main.go
./server
INFO[0000] Starting HTTP server

The server will serve the service on http://localhost:8080/api.

Tests

We've implemented some tests for you. You can run them with:

foo@bar:~$ make test
go test -race ./... -coverpkg=./... -coverprofile=cover.txt
?       github.com/tanninio/home-assignment/internal/app        [no test files]
?       github.com/tanninio/home-assignment/internal/common     [no test files]
ok      github.com/tanninio/home-assignment/cmd/app     1.635s  coverage: 64.0% of statements in ./...
ok      github.com/tanninio/home-assignment/internal/adapters   1.972s  coverage: 44.8% of statements in ./...
ok      github.com/tanninio/home-assignment/internal/ports/http 2.255s  coverage: 3.9% of statements in ./...