feat: add Readiness middleware

feat: update chi to v5
feat: update gh action
fix: update some comments

.github/workflows/go.yml

@@ -8,12 +8,11 @@ jobs:
     steps:
 
     - name: Set up Go
-      uses: actions/setup-go@v1
+      uses: actions/setup-go@v2
       with:
-        go-version: 1.13
-      id: go
+        go-version: "^1.16"
 
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
 
     - name: Test
       run: go test -race -coverprofile=coverage.out -covermode=atomic

go.mod

@@ -4,7 +4,7 @@ go 1.13
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/go-chi/chi v4.0.3+incompatible
+	github.com/go-chi/chi/v5 v5.0.3 // indirect
 	github.com/stretchr/testify v1.3.0
 	golang.org/x/net v0.0.0-20190620200207-3b0461eec859 // indirect
 )

go.sum

@@ -3,6 +3,8 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/go-chi/chi v4.0.3+incompatible h1:gakN3pDJnzZN5jqFV2TEdF66rTfKeITyR8qu6ekICEY=
 github.com/go-chi/chi v4.0.3+incompatible/go.mod h1:eB3wogJHnLi3x/kFX2A+IbTBlXxmMeXJVKy9tTv1XzQ=
+github.com/go-chi/chi/v5 v5.0.3 h1:khYQBdPivkYG1s1TAzDQG1f6eX4kD2TItYVZexL5rS4=
+github.com/go-chi/chi/v5 v5.0.3/go.mod h1:DslCQbL2OYiznFReuXYUmQ2hGd1aDpCnlMNITLSKoi8=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=

middleware.go

@@ -1,11 +1,12 @@
 package rest
 
 import (
-	"github.com/go-chi/chi/middleware"
+	"github.com/go-chi/chi/v5/middleware"
 	"log"
 	"net/http"
 	"net/url"
 	"strings"
+	"sync/atomic"
 	"time"
 )
 
@@ -39,3 +40,14 @@ func Logger(next http.Handler) http.Handler {
 	}
 	return http.HandlerFunc(fn)
 }
+
+// Readiness - middleware for the readiness probe
+func Readiness(isReady *atomic.Value) http.HandlerFunc {
+	return func(w http.ResponseWriter, _ *http.Request) {
+		if isReady == nil || !isReady.Load().(bool) {
+			http.Error(w, http.StatusText(http.StatusServiceUnavailable), http.StatusServiceUnavailable)
+			return
+		}
+		w.WriteHeader(http.StatusOK)
+	}
+}

middleware_test.go

@@ -7,6 +7,7 @@ import (
 	"log"
 	"net/http"
 	"net/http/httptest"
+	"sync/atomic"
 	"testing"
 )
 
@@ -26,3 +27,27 @@ func TestLogger(t *testing.T) {
 	fmt.Println(buf.String())
 	require.NotEmpty(t, buf)
 }
+
+func TestReadiness(t *testing.T) {
+	isReady := &atomic.Value{}
+	isReady.Store(false)
+
+	ts := httptest.NewServer(Readiness(isReady))
+	defer ts.Close()
+
+	resp, err := http.Get(ts.URL)
+	require.NoError(t, err)
+	require.Equal(t, http.StatusServiceUnavailable, resp.StatusCode)
+
+	isReady.Store(true)
+
+	resp, err = http.Get(ts.URL)
+	require.NoError(t, err)
+	require.Equal(t, http.StatusOK, resp.StatusCode)
+
+	isReady.Store(false)
+
+	resp, err = http.Get(ts.URL)
+	require.NoError(t, err)
+	require.Equal(t, http.StatusServiceUnavailable, resp.StatusCode)
+}

request.go

@@ -12,7 +12,7 @@ import (
 var ErrEmptyRequest = errors.New("empty request")
 var ErrNotPointer = errors.New("not pointer provided")
 
-// Read body from request and trying to unmarshal to provided struct.
+// ReadBody - read body from request and trying to unmarshal to provided struct
 func ReadBody(w http.ResponseWriter, r *http.Request, str interface{}) error {
 	if r == nil {
 		return ErrEmptyRequest

response.go

@@ -10,7 +10,7 @@ import (
 	"strings"
 )
 
-// HttpError - structure for http errors.
+// HttpError - structure for http errors
 type HttpError struct {
 	Err     string `json:"error"`
 	Message string `json:"message,omitempty"`
@@ -23,12 +23,12 @@ var (
 	ErrNotFound     = errors.New("NOT_FOUND")
 )
 
-// Just to confirm Error interface.
+// Just to confirm Error interface
 func (e HttpError) Error() string {
 	return e.Err
 }
 
-// RenderJSON sends data as json.
+// RenderJSON sends data as json
 func RenderJSON(w http.ResponseWriter, code int, data interface{}) {
 	buf := &bytes.Buffer{}
 	enc := json.NewEncoder(buf)
@@ -48,12 +48,12 @@ func RenderJSON(w http.ResponseWriter, code int, data interface{}) {
 	_, _ = w.Write(buf.Bytes())
 }
 
-// JsonResponse - write a response with application/json Content-Type header.
+// JsonResponse - write a response with application/json Content-Type header
 func JsonResponse(w http.ResponseWriter, data interface{}) {
 	RenderJSON(w, http.StatusOK, data)
 }
 
-// OKResponse - write a OK response with application/json Content-Type header.
+// OkResponse - write a OK response with application/json Content-Type header
 func OkResponse(w http.ResponseWriter) {
 	RenderJSON(w, http.StatusOK, struct {
 		OK bool `json:"ok"`
@@ -62,7 +62,7 @@ func OkResponse(w http.ResponseWriter) {
 	})
 }
 
-// JsonError - write a HttpError structure as response.
+// ErrorResponse - write a HttpError structure as response
 func ErrorResponse(w http.ResponseWriter, r *http.Request, code int, error error, msg string) {
 	err := HttpError{
 		Err:     http.StatusText(code),

server.go

@@ -5,12 +5,14 @@ import (
 	"fmt"
 	"log"
 	"net/http"
+	"sync/atomic"
 	"time"
 )
 
-// Server - http server struct.
+// Server - http server struct
 type Server struct {
-	Port int
+	Port    int
+	IsReady *atomic.Value
 
 	ReadHeaderTimeout time.Duration
 	WriteTimeout      time.Duration
@@ -25,11 +27,16 @@ func handler(w http.ResponseWriter, r *http.Request) {
 	_, _ = w.Write([]byte("."))
 }
 
-// Run - will initialize server and run it on provided port.
+// Run - will initialize server and run it on provided port
 func (s *Server) Run(router http.Handler) error {
 	if s.Port == 0 {
 		s.Port = 8080
 	}
+	if s.IsReady == nil {
+		s.IsReady = &atomic.Value{}
+		s.IsReady.Store(true)
+	}
+
 	if s.ReadHeaderTimeout == 0 {
 		s.ReadHeaderTimeout = 10 * time.Second
 	}
@@ -39,10 +46,12 @@ func (s *Server) Run(router http.Handler) error {
 	if s.IdleTimeout == 0 {
 		s.IdleTimeout = 60 * time.Second
 	}
+
 	if router == nil {
 		mux := http.NewServeMux()
 		mux.HandleFunc("/ping", handler)
 		mux.HandleFunc("/liveness", handler)
+		mux.HandleFunc("/readiness", Readiness(s.IsReady))
 		router = mux
 	}
 
@@ -63,7 +72,7 @@ func (s *Server) Run(router http.Handler) error {
 	return nil
 }
 
-// Shutdown - shutdown http server.
+// Shutdown - shutdown http server
 func (s *Server) Shutdown(ctx context.Context) error {
 	log.Print("[INFO] shutdown rest server")
 

server_test.go

@@ -53,6 +53,7 @@ func TestServer_Run_EmptyRouter(t *testing.T) {
 	srv := &Server{
 		Port: 1234,
 	}
+
 	defer func() {
 		require.NoError(t, srv.Shutdown(context.Background()))
 	}()
@@ -62,13 +63,23 @@ func TestServer_Run_EmptyRouter(t *testing.T) {
 	}()
 
 	host := fmt.Sprintf("http://localhost:%d", srv.Port)
-	resp, err := http.Get(host+"/ping")
+	resp, err := http.Get(host + "/ping")
+	require.NoError(t, err)
+	require.Equal(t, http.StatusOK, resp.StatusCode)
+
+	resp, err = http.Get(host + "/liveness")
 	require.NoError(t, err)
 	require.Equal(t, http.StatusOK, resp.StatusCode)
 
-	resp, err = http.Get(host+"/liveness")
+	resp, err = http.Get(host + "/readiness")
 	require.NoError(t, err)
 	require.Equal(t, http.StatusOK, resp.StatusCode)
+
+	srv.IsReady.Store(false)
+
+	resp, err = http.Get(host + "/readiness")
+	require.NoError(t, err)
+	require.Equal(t, http.StatusServiceUnavailable, resp.StatusCode)
 }
 
 func TestServer_Shutdown(t *testing.T) {