Publish ITWorx Pulse source

internal/problem/problem.go

@@ -0,0 +1,35 @@
+package problem
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/itworx/pulse/internal/correlation"
+)
+
+type Details struct {
+	Type          string            `json:"type"`
+	Title         string            `json:"title"`
+	Status        int               `json:"status"`
+	Code          string            `json:"code"`
+	Detail        string            `json:"detail"`
+	CorrelationID string            `json:"correlationId"`
+	Fields        map[string]string `json:"fields,omitempty"`
+}
+
+func Write(response http.ResponseWriter, request *http.Request, status int, code, title, detail string, fields map[string]string) {
+	id := correlation.FromContext(request.Context())
+	if id == "" {
+		id = correlation.New()
+	}
+	details := Details{Type: "https://pulse.local/problems/" + code, Title: title, Status: status, Code: code, Detail: detail, CorrelationID: id, Fields: fields}
+	response.Header().Set("Content-Type", "application/problem+json")
+	response.Header().Set("Cache-Control", "private, no-store")
+	response.Header().Set(correlation.Header, id)
+	response.WriteHeader(status)
+	_ = json.NewEncoder(response).Encode(details)
+}
+
+func Middleware(next http.Handler) http.Handler {
+	return correlation.Middleware(next)
+}

internal/problem/problem_test.go

@@ -0,0 +1,34 @@
+package problem
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/itworx/pulse/internal/correlation"
+)
+
+func TestWriteProducesSafeProblemDetails(t *testing.T) {
+	handler := correlation.Middleware(http.HandlerFunc(func(response http.ResponseWriter, request *http.Request) {
+		Write(response, request, http.StatusBadRequest, "INVALID_INPUT", "Invalid input", "The request could not be accepted.", nil)
+	}))
+	request := httptest.NewRequest(http.MethodGet, "/", nil)
+	request.Header.Set(correlation.Header, "corr-1234")
+	response := httptest.NewRecorder()
+	handler.ServeHTTP(response, request)
+	var details Details
+	if err := json.Unmarshal(response.Body.Bytes(), &details); err != nil {
+		t.Fatal(err)
+	}
+	if details.Status != http.StatusBadRequest || details.CorrelationID != "corr-1234" || details.Code != "INVALID_INPUT" {
+		t.Fatalf("unexpected problem: %#v", details)
+	}
+	if response.Header().Get("Cache-Control") != "private, no-store" {
+		t.Fatalf("problem response cache control = %q", response.Header().Get("Cache-Control"))
+	}
+	if strings.Contains(response.Body.String(), "stack") || strings.Contains(response.Body.String(), "goroutine") {
+		t.Fatal("problem response contains implementation details")
+	}
+}