Init: bootstrap go module with basic framework

middlewares/errorHandler.go

@@ -0,0 +1,87 @@
+package middlewares
+
+import (
+	"net/http"
+
+	"gitea.konchin.com/service/amane-tanikaze-dcbot/amane/tracing"
+	"github.com/uptrace/bunrouter"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/trace"
+	"go.uber.org/zap"
+)
+
+type HTTPError struct {
+	StatusCode  int    `json:"code"`
+	Message     string `json:"message"`
+	OriginError error  `json:"-"`
+}
+
+func (e HTTPError) Error() string {
+	return e.Message
+}
+
+func NewHTTPError(err error) HTTPError {
+	return HTTPError{
+		StatusCode:  http.StatusInternalServerError,
+		Message:     "Internal server error with unknown reason",
+		OriginError: err,
+	}
+}
+
+func (self *Handlers) ErrorHandler(
+	next bunrouter.HandlerFunc,
+) bunrouter.HandlerFunc {
+	return func(w http.ResponseWriter, req bunrouter.Request) error {
+		err := next(w, req)
+		ctx := req.Context()
+
+		var httpErr HTTPError
+		switch err := err.(type) {
+		case nil:
+			return nil
+
+		case HTTPError:
+			httpErr = err
+
+		default:
+			tracing.Logger.Ctx(ctx).
+				Error("unhandled error",
+					zap.Error(err))
+			httpErr = NewHTTPError(err)
+		}
+
+		// https://opentelemetry.io/docs/specs/semconv/http/http-spans/#status
+		span := trace.SpanFromContext(ctx)
+		span.SetAttributes(
+			attribute.Int("http.response.status_code", httpErr.StatusCode),
+		)
+
+		if 500 <= httpErr.StatusCode && httpErr.StatusCode <= 599 {
+			span.SetStatus(codes.Error, err.Error())
+			if httpErr.OriginError == nil {
+				tracing.Logger.Ctx(ctx).
+					Error(httpErr.Message)
+			} else {
+				tracing.Logger.Ctx(ctx).
+					Error(httpErr.Message,
+						zap.Error(httpErr.OriginError))
+			}
+		} else {
+			span.SetStatus(codes.Ok, "")
+			if httpErr.OriginError == nil {
+				tracing.Logger.Ctx(ctx).
+					Warn(httpErr.Message)
+			} else {
+				tracing.Logger.Ctx(ctx).
+					Warn(httpErr.Message,
+						zap.Error(httpErr.OriginError))
+			}
+		}
+
+		w.WriteHeader(httpErr.StatusCode)
+		_ = bunrouter.JSON(w, httpErr)
+
+		return err
+	}
+}

middlewares/handlers.go

@@ -0,0 +1,11 @@
+package middlewares
+
+import "github.com/uptrace/bun"
+
+type Handlers struct {
+	db *bun.DB
+}
+
+func NewHandlers(db *bun.DB) *Handlers {
+	return &Handlers{db: db}
+}