learningbyexample/go-microservice

A educational project for creating a microservice in go

go-microservice's Issues

all store methods should return an error

All store method should return an error, with this we could prepare better for stores that are more complex than the in-memory datastore

go-microservice/internal/app/store/store.go

Lines 30 to 36 in 013cf2b

	type PetStore interface {
	AddPet(name string, race string, mod string) int
	GetPet(id int) (data.Pet, error)
	GetAllPets() []data.Pet
	DeletePet(id int) error
	UpdatePet(id int, name string, race string, mod string) (bool, error)
	}

Implement liveness and readiness endpoints

In we want to deploy this service in a k8s cluster we need to have liveness and readiness endpoints

Get list

we should have a get all the pets in our store

adding configuration arguments

we need a way to have configuration arguments

Change project layout to match standards

follow this structure

https://github.com/golang-standards/project-layout

Bad port test is stack when running tests

In the bad.port.json the port 49 is a problem when we run the tests. We should change it to avoid tests stack.

{
	"server": {
		"port": 49
	},
	"store": {
		"name": "in-memory"
	}
}

Implement PUT

We currently have POST but we need to implement PUT

Log errors in the server

When we get an error during a request we should see the trace in the server log.

adding go vet

Currently, we are not running go vet, and we should, in fact, we have a couple of go vet errors already

$ go vet ./internal/app/...       
# github.com/LearningByExample/go-microservice/internal/app/store/memory
internal/app/store/memory/memory.go:107:9: Open passes lock by value: github.com/LearningByExample/go-microservice/internal/app/store/memory.inMemoryPetStore contains sync.RWMutex
internal/app/store/memory/memory.go:112:9: Close passes lock by value: github.com/LearningByExample/go-microservice/internal/app/store/memory.inMemoryPetStore contains sync.RWMutex

in memory store ids are not correctly generated

since we use only the len of the map the id is incorrect, we need to use a lastId value as before

improve code coverage

the code coverage is quite low in some areas, we should improve it

Implement PostgreSQL datastore

We should implement a PostgreSQL.

• create a new pet store
• create a new provider
• add default config files
• mock database

concurrency bug in in memory data store

I've added a new test, currently skipped, that shows a concurrency problem on in memory data store

go-microservice/internal/app/store/memory/memory_test.go

Lines 215 to 244 in 013cf2b

	func TestConcurrency(t *testing.T) {
	t.Skipf("skiping test, need to fix concurrency")
	ps := NewInMemoryPetStore()
	wantedCount := 1000
	var wg sync.WaitGroup
	wg.Add(wantedCount)
	for i := 0; i < wantedCount; i++ {
	go func(w *sync.WaitGroup) {
	seqName := fmt.Sprintf("Fluff%d", wantedCount)
	id := ps.AddPet(seqName, "dog", "happy")
	_, _ = ps.GetPet(id)
	newName := fmt.Sprintf("Fluffy%d", wantedCount)
	_, _ = ps.UpdatePet(id, newName, "dog", "happy")
	_, _ = ps.GetPet(id)
	_ = ps.GetAllPets()
	_ = ps.DeletePet(id)
	_ = ps.GetAllPets()
	w.Done()
	}(&wg)
	}
	wg.Wait()
	total := len(ps.GetAllPets())
	wantTotal := 0
	if total != wantTotal {
	t.Fatalf("want %q, got %v", wantTotal, total)
	}
	}

memory_test.go fails sometimes when we run all tests

We should fix the array order. This is a reference to take into account to fix it:
https://golang.org/pkg/sort/

func (s *inMemoryPetStore) GetAllPets() ([]data.Pet, error) {
	s.mu.RLock()
	defer s.mu.RUnlock()
	result := make([]data.Pet, 0, len(s.pets))
	for k := range s.pets {
		result = append(result, s.pets[k])
	}
	return result, nil
}

use travis to test on push

https://docs.travis-ci.com/user/languages/go/

Create new assert functions for validate OK responses

Now that we have an assert function for validating errors :

go-microservice/server/pet_test.go

Line 205 in d470e8e

func assertResponseError(t *testing.T, response *httptest.ResponseRecorder, error ErrorResponse) {

We should create a new function for validating OK responses

update README with HTTPie requests

We need on the README HTTPie example requests

Create a k8s deployment

We like to have a k8s deployment for this service

GET on /pet/1 log superflous write header

When doing a GET on a resource

$ http :8080/pet/1

we get on the log :

2020/02/16 17:05:03 http: superfluous response.WriteHeader call from github.com/LearningByExample/go-microservice/server.petHandler.ServeHTTP (pet.go:132)

change pet handler test to use SpyStore

Currently, the handler test use mostly InMemoryStore, it should use the SpyStore

Remove InMemoryStore from server tests

The Server Tests use the InMemoryStore

go-microservice/server/server_test.go

Line 26 in 772df75

"github.com/LearningByExample/go-microservice/store/memory"

We should as well refactor the tests to make our helpers and spy reusable

server does not error when already listen

when we run the server and is already running the application exit without erroring

adding configuration file

we need a configuration file for handling things such connections

Better HTTP responses

currently when validating a pet we just a generic error, we should get the fields that are not ok in the validation

using test containers

With test containers, we could run the integration test against a real PSQL and as well in Travis

https://github.com/testcontainers/testcontainers-go

Add Connection pool settings

we need to add the connection pool settings for a database

see https://www.alexedwards.net/blog/configuring-sqldb

Add graceful shutdown

In order to behave propertly we need to handle a gracefult shutdown of the server