feat: ensure public API consistently uses slog.Logger

Previously some of the public API had been altered to take the
(internal) Blog logger. This is not correct, so the public API should
now consistely take a *slog.Logger, and a Blog logger now implements the
slog.Handler interface so can easily be converted to a slog.Logger.

domain/apiresponses/failure_responses.go

@@ -1,11 +1,9 @@
 package apiresponses
 
 import (
-	"errors"
 	"fmt"
+	"log/slog"
 	"net/http"
-
-	"github.com/pivotal-cf/brokerapi/v10/internal/blog"
 )
 
 // FailureResponse can be returned from any of the `ServiceBroker` interface methods
@@ -44,9 +42,11 @@ func (f *FailureResponse) ErrorResponse() interface{} {
 	}
 }
 
-func (f *FailureResponse) ValidatedStatusCode(logger blog.Blog) int {
+func (f *FailureResponse) ValidatedStatusCode(logger *slog.Logger) int {
 	if f.statusCode < 400 || 600 <= f.statusCode {
-		logger.Error("validating-status-code", errors.New("Invalid failure http response code: 600, expected 4xx or 5xx, returning internal server error: 500."))
+		if logger != nil {
+			logger.Error("validating-status-code", slog.String("error", "Invalid failure http response code: 600, expected 4xx or 5xx, returning internal server error: 500."))
+		}
 		return http.StatusInternalServerError
 	}
 	return f.statusCode

domain/apiresponses/failure_responses_test.go

@@ -9,16 +9,9 @@ import (
 	. "github.com/onsi/gomega"
 	"github.com/onsi/gomega/gbytes"
 	"github.com/pivotal-cf/brokerapi/v10/domain/apiresponses"
-	"github.com/pivotal-cf/brokerapi/v10/internal/blog"
 )
 
 var _ = Describe("FailureResponse", func() {
-	var fakeLogger blog.Blog
-
-	BeforeEach(func() {
-		fakeLogger = blog.New(slog.New(slog.NewJSONHandler(GinkgoWriter, nil)))
-	})
-
 	Describe("ErrorResponse", func() {
 		It("returns a ErrorResponse containing the error message", func() {
 			failureResponse := asFailureResponse(apiresponses.NewFailureResponse(errors.New("my error message"), http.StatusForbidden, "log-key"))
@@ -53,7 +46,7 @@ var _ = Describe("FailureResponse", func() {
 			newError := failureResponse.AppendErrorMessage("and some more details")
 
 			Expect(newError.Error()).To(Equal("my error message and some more details"))
-			Expect(newError.ValidatedStatusCode(fakeLogger)).To(Equal(http.StatusForbidden))
+			Expect(newError.ValidatedStatusCode(nil)).To(Equal(http.StatusForbidden))
 			Expect(newError.LoggerAction()).To(Equal(failureResponse.LoggerAction()))
 
 			errorResponse, typeCast := newError.ErrorResponse().(apiresponses.ErrorResponse)
@@ -69,7 +62,7 @@ var _ = Describe("FailureResponse", func() {
 			newError := failureResponse.AppendErrorMessage("and some more details")
 
 			Expect(newError.Error()).To(Equal("my error message and some more details"))
-			Expect(newError.ValidatedStatusCode(fakeLogger)).To(Equal(http.StatusForbidden))
+			Expect(newError.ValidatedStatusCode(nil)).To(Equal(http.StatusForbidden))
 			Expect(newError.LoggerAction()).To(Equal(failureResponse.LoggerAction()))
 			Expect(newError.ErrorResponse()).To(Equal(failureResponse.ErrorResponse()))
 		})
@@ -78,23 +71,23 @@ var _ = Describe("FailureResponse", func() {
 	Describe("ValidatedStatusCode", func() {
 		It("returns the status code that was passed in", func() {
 			failureResponse := asFailureResponse(apiresponses.NewFailureResponse(errors.New("my error message"), http.StatusForbidden, "log-key"))
-			Expect(failureResponse.ValidatedStatusCode(fakeLogger)).To(Equal(http.StatusForbidden))
+			Expect(failureResponse.ValidatedStatusCode(nil)).To(Equal(http.StatusForbidden))
 		})
 
 		It("when error key is provided it returns the status code that was passed in", func() {
 			failureResponse := apiresponses.NewFailureResponseBuilder(errors.New("my error message"), http.StatusForbidden, "log-key").WithErrorKey("error key").Build()
-			Expect(failureResponse.ValidatedStatusCode(fakeLogger)).To(Equal(http.StatusForbidden))
+			Expect(failureResponse.ValidatedStatusCode(nil)).To(Equal(http.StatusForbidden))
 		})
 
 		Context("when the status code is invalid", func() {
 			It("returns 500", func() {
 				failureResponse := asFailureResponse(apiresponses.NewFailureResponse(errors.New("my error message"), 600, "log-key"))
-				Expect(failureResponse.ValidatedStatusCode(fakeLogger)).To(Equal(http.StatusInternalServerError))
+				Expect(failureResponse.ValidatedStatusCode(nil)).To(Equal(http.StatusInternalServerError))
 			})
 
 			It("logs that the status has been changed", func() {
 				log := gbytes.NewBuffer()
-				logger := blog.New(slog.New(slog.NewJSONHandler(log, nil)))
+				logger := slog.New(slog.NewJSONHandler(log, nil))
 				failureResponse := asFailureResponse(apiresponses.NewFailureResponse(errors.New("my error message"), 600, "log-key"))
 				failureResponse.ValidatedStatusCode(logger)
 				Expect(log).To(gbytes.Say("Invalid failure http response code: 600, expected 4xx or 5xx, returning internal server error: 500."))

failure_response_test.go

@@ -25,16 +25,9 @@ import (
 	"github.com/onsi/gomega/gbytes"
 	"github.com/pivotal-cf/brokerapi/v10"
 	"github.com/pivotal-cf/brokerapi/v10/domain/apiresponses"
-	"github.com/pivotal-cf/brokerapi/v10/internal/blog"
 )
 
 var _ = Describe("FailureResponse", func() {
-	var fakeLogger blog.Blog
-
-	BeforeEach(func() {
-		fakeLogger = blog.New(slog.New(slog.NewJSONHandler(GinkgoWriter, nil)))
-	})
-
 	Describe("ErrorResponse", func() {
 		It("returns a ErrorResponse containing the error message", func() {
 			failureResponse := asFailureResponse(brokerapi.NewFailureResponse(errors.New("my error message"), http.StatusForbidden, "log-key"))
@@ -69,7 +62,7 @@ var _ = Describe("FailureResponse", func() {
 			newError := failureResponse.AppendErrorMessage("and some more details")
 
 			Expect(newError.Error()).To(Equal("my error message and some more details"))
-			Expect(newError.ValidatedStatusCode(fakeLogger)).To(Equal(http.StatusForbidden))
+			Expect(newError.ValidatedStatusCode(nil)).To(Equal(http.StatusForbidden))
 			Expect(newError.LoggerAction()).To(Equal(failureResponse.LoggerAction()))
 
 			errorResponse, typeCast := newError.ErrorResponse().(brokerapi.ErrorResponse)
@@ -85,7 +78,7 @@ var _ = Describe("FailureResponse", func() {
 			newError := failureResponse.AppendErrorMessage("and some more details")
 
 			Expect(newError.Error()).To(Equal("my error message and some more details"))
-			Expect(newError.ValidatedStatusCode(fakeLogger)).To(Equal(http.StatusForbidden))
+			Expect(newError.ValidatedStatusCode(nil)).To(Equal(http.StatusForbidden))
 			Expect(newError.LoggerAction()).To(Equal(failureResponse.LoggerAction()))
 			Expect(newError.ErrorResponse()).To(Equal(failureResponse.ErrorResponse()))
 		})
@@ -94,23 +87,23 @@ var _ = Describe("FailureResponse", func() {
 	Describe("ValidatedStatusCode", func() {
 		It("returns the status code that was passed in", func() {
 			failureResponse := asFailureResponse(brokerapi.NewFailureResponse(errors.New("my error message"), http.StatusForbidden, "log-key"))
-			Expect(failureResponse.ValidatedStatusCode(fakeLogger)).To(Equal(http.StatusForbidden))
+			Expect(failureResponse.ValidatedStatusCode(nil)).To(Equal(http.StatusForbidden))
 		})
 
 		It("when error key is provided it returns the status code that was passed in", func() {
 			failureResponse := brokerapi.NewFailureResponseBuilder(errors.New("my error message"), http.StatusForbidden, "log-key").WithErrorKey("error key").Build()
-			Expect(failureResponse.ValidatedStatusCode(fakeLogger)).To(Equal(http.StatusForbidden))
+			Expect(failureResponse.ValidatedStatusCode(nil)).To(Equal(http.StatusForbidden))
 		})
 
 		Context("when the status code is invalid", func() {
 			It("returns 500", func() {
 				failureResponse := asFailureResponse(brokerapi.NewFailureResponse(errors.New("my error message"), 600, "log-key"))
-				Expect(failureResponse.ValidatedStatusCode(fakeLogger)).To(Equal(http.StatusInternalServerError))
+				Expect(failureResponse.ValidatedStatusCode(nil)).To(Equal(http.StatusInternalServerError))
 			})
 
 			It("logs that the status has been changed", func() {
 				log := gbytes.NewBuffer()
-				logger := blog.New(slog.New(slog.NewJSONHandler(log, nil)))
+				logger := slog.New(slog.NewJSONHandler(log, nil))
 				failureResponse := asFailureResponse(brokerapi.NewFailureResponse(errors.New("my error message"), 600, "log-key"))
 				failureResponse.ValidatedStatusCode(logger)
 				Expect(log).To(gbytes.Say("Invalid failure http response code: 600, expected 4xx or 5xx, returning internal server error: 500."))

handlers/bind.go

@@ -3,6 +3,7 @@ package handlers
 import (
 	"encoding/json"
 	"fmt"
+	"log/slog"
 	"net/http"
 
 	"github.com/pivotal-cf/brokerapi/v10/internal/blog"
@@ -61,7 +62,7 @@ func (h APIHandler) Bind(w http.ResponseWriter, req *http.Request) {
 	if err != nil {
 		switch err := err.(type) {
 		case *apiresponses.FailureResponse:
-			statusCode := err.ValidatedStatusCode(logger)
+			statusCode := err.ValidatedStatusCode(slog.New(logger))
 			errorResponse := err.ErrorResponse()
 			if err == apiresponses.ErrInstanceDoesNotExist {
 				// work around ErrInstanceDoesNotExist having different pre-refactor behaviour to other actions

handlers/catalog.go

@@ -2,6 +2,7 @@ package handlers
 
 import (
 	"fmt"
+	"log/slog"
 	"net/http"
 
 	"github.com/pivotal-cf/brokerapi/v10/domain/apiresponses"
@@ -19,7 +20,7 @@ func (h *APIHandler) Catalog(w http.ResponseWriter, req *http.Request) {
 		switch err := err.(type) {
 		case *apiresponses.FailureResponse:
 			logger.Error(err.LoggerAction(), err)
-			h.respond(w, err.ValidatedStatusCode(logger), requestId, err.ErrorResponse())
+			h.respond(w, err.ValidatedStatusCode(slog.New(logger)), requestId, err.ErrorResponse())
 		default:
 			logger.Error(unknownErrorKey, err)
 			h.respond(w, http.StatusInternalServerError, requestId, apiresponses.ErrorResponse{

handlers/deprovision.go

@@ -2,6 +2,7 @@ package handlers
 
 import (
 	"fmt"
+	"log/slog"
 	"net/http"
 
 	"github.com/pivotal-cf/brokerapi/v10/internal/blog"
@@ -50,7 +51,7 @@ func (h APIHandler) Deprovision(w http.ResponseWriter, req *http.Request) {
 		switch err := err.(type) {
 		case *apiresponses.FailureResponse:
 			logger.Error(err.LoggerAction(), err)
-			h.respond(w, err.ValidatedStatusCode(logger), requestId, err.ErrorResponse())
+			h.respond(w, err.ValidatedStatusCode(slog.New(logger)), requestId, err.ErrorResponse())
 		default:
 			logger.Error(unknownErrorKey, err)
 			h.respond(w, http.StatusInternalServerError, requestId, apiresponses.ErrorResponse{

handlers/get_binding.go

@@ -3,6 +3,7 @@ package handlers
 import (
 	"errors"
 	"fmt"
+	"log/slog"
 	"net/http"
 
 	"github.com/pivotal-cf/brokerapi/v10/internal/blog"
@@ -43,7 +44,7 @@ func (h APIHandler) GetBinding(w http.ResponseWriter, req *http.Request) {
 		switch err := err.(type) {
 		case *apiresponses.FailureResponse:
 			logger.Error(err.LoggerAction(), err)
-			h.respond(w, err.ValidatedStatusCode(logger), requestId, err.ErrorResponse())
+			h.respond(w, err.ValidatedStatusCode(slog.New(logger)), requestId, err.ErrorResponse())
 		default:
 			logger.Error(unknownErrorKey, err)
 			h.respond(w, http.StatusInternalServerError, requestId, apiresponses.ErrorResponse{

handlers/get_instance.go

@@ -3,6 +3,7 @@ package handlers
 import (
 	"errors"
 	"fmt"
+	"log/slog"
 	"net/http"
 
 	"github.com/pivotal-cf/brokerapi/v10/internal/blog"
@@ -42,7 +43,7 @@ func (h APIHandler) GetInstance(w http.ResponseWriter, req *http.Request) {
 		switch err := err.(type) {
 		case *apiresponses.FailureResponse:
 			logger.Error(err.LoggerAction(), err)
-			h.respond(w, err.ValidatedStatusCode(logger), requestId, err.ErrorResponse())
+			h.respond(w, err.ValidatedStatusCode(slog.New(logger)), requestId, err.ErrorResponse())
 		default:
 			logger.Error(unknownErrorKey, err)
 			h.respond(w, http.StatusInternalServerError, requestId, apiresponses.ErrorResponse{

handlers/last_binding_operation.go

@@ -45,7 +45,7 @@ func (h APIHandler) LastBindingOperation(w http.ResponseWriter, req *http.Reques
 		switch err := err.(type) {
 		case *apiresponses.FailureResponse:
 			logger.Error(err.LoggerAction(), err)
-			h.respond(w, err.ValidatedStatusCode(logger), requestId, err.ErrorResponse())
+			h.respond(w, err.ValidatedStatusCode(slog.New(logger)), requestId, err.ErrorResponse())
 		default:
 			logger.Error(unknownErrorKey, err)
 			h.respond(w, http.StatusInternalServerError, requestId, apiresponses.ErrorResponse{

handlers/last_operation.go

@@ -33,7 +33,7 @@ func (h APIHandler) LastOperation(w http.ResponseWriter, req *http.Request) {
 		switch err := err.(type) {
 		case *apiresponses.FailureResponse:
 			logger.Error(err.LoggerAction(), err)
-			h.respond(w, err.ValidatedStatusCode(logger), requestId, err.ErrorResponse())
+			h.respond(w, err.ValidatedStatusCode(slog.New(logger)), requestId, err.ErrorResponse())
 		default:
 			logger.Error(unknownErrorKey, err)
 			h.respond(w, http.StatusInternalServerError, requestId, apiresponses.ErrorResponse{

handlers/provision.go

@@ -98,7 +98,7 @@ func (h *APIHandler) Provision(w http.ResponseWriter, req *http.Request) {
 		switch err := err.(type) {
 		case *apiresponses.FailureResponse:
 			logger.Error(err.LoggerAction(), err)
-			h.respond(w, err.ValidatedStatusCode(logger), requestId, err.ErrorResponse())
+			h.respond(w, err.ValidatedStatusCode(slog.New(logger)), requestId, err.ErrorResponse())
 		default:
 			logger.Error(unknownErrorKey, err)
 			h.respond(w, http.StatusInternalServerError, requestId, apiresponses.ErrorResponse{

handlers/unbind.go

@@ -2,6 +2,7 @@ package handlers
 
 import (
 	"fmt"
+	"log/slog"
 	"net/http"
 
 	"github.com/go-chi/chi/v5"
@@ -48,7 +49,7 @@ func (h APIHandler) Unbind(w http.ResponseWriter, req *http.Request) {
 		switch err := err.(type) {
 		case *apiresponses.FailureResponse:
 			logger.Error(err.LoggerAction(), err)
-			h.respond(w, err.ValidatedStatusCode(logger), requestId, err.ErrorResponse())
+			h.respond(w, err.ValidatedStatusCode(slog.New(logger)), requestId, err.ErrorResponse())
 		default:
 			logger.Error(unknownErrorKey, err)
 			h.respond(w, http.StatusInternalServerError, requestId, apiresponses.ErrorResponse{

handlers/update.go

@@ -3,6 +3,7 @@ package handlers
 import (
 	"encoding/json"
 	"fmt"
+	"log/slog"
 	"net/http"
 	"strconv"
 
@@ -46,7 +47,7 @@ func (h APIHandler) Update(w http.ResponseWriter, req *http.Request) {
 		switch err := err.(type) {
 		case *apiresponses.FailureResponse:
 			logger.Error(err.LoggerAction(), err)
-			h.respond(w, err.ValidatedStatusCode(logger), requestId, err.ErrorResponse())
+			h.respond(w, err.ValidatedStatusCode(slog.New(logger)), requestId, err.ErrorResponse())
 		default:
 			logger.Error(unknownErrorKey, err)
 			h.respond(w, http.StatusInternalServerError, requestId, apiresponses.ErrorResponse{

internal/blog/blog.go

@@ -3,6 +3,9 @@
 // and it relied on some idiosyncrasies of that logger that are not found in the (subsequently written)
 // Go standard library log/slog logger. This package is a wrapper around log/slog that adds back the
 // idiosyncrasies of lager, minimizes boilerplate code, and keeps the behavior as similar as possible.
+// It also implements the slog.Handler interface so that it can easily be converted into a slog.Logger.
+// This is useful when calling public APIs (such as FailureResponse.ValidatedStatusCode) which take a
+// slog.Logger as an input, and because they are public cannot take a Blog as in input.
 package blog
 
 import (
@@ -28,6 +31,8 @@ func New(logger *slog.Logger) Blog {
 	return Blog{logger: logger}
 }
 
+// Session emulates a Lager logger session. It returns a new logger that will always log the
+// attributes, prefix, and data from the context.
 func (b Blog) Session(ctx context.Context, prefix string, attr ...any) Blog {
 	for _, key := range []middlewares.ContextKey{middlewares.CorrelationIDKey, middlewares.RequestIdentityKey} {
 		if value := ctx.Value(key); value != nil {
@@ -41,23 +46,62 @@ func (b Blog) Session(ctx context.Context, prefix string, attr ...any) Blog {
 	}
 }
 
+// Error logs an error. It takes an error type as a convenience, which is different to slog.Logger.Error()
 func (b Blog) Error(message string, err error, attr ...any) {
 	b.logger.Error(join(b.prefix, message), append([]any{slog.Any(errorKey, err)}, attr...)...)
 }
 
+// Info logs information. It behaves a lot file slog.Logger.Info()
 func (b Blog) Info(message string, attr ...any) {
 	b.logger.Info(join(b.prefix, message), attr...)
 }
 
+// With returns a logger that always logs the specified attributes
 func (b Blog) With(attr ...any) Blog {
 	b.logger = b.logger.With(attr...)
 	return b
 }
 
+// Enabled is required implement the slog.Handler interface
+func (b Blog) Enabled(context.Context, slog.Level) bool {
+	return true
+}
+
+// WithAttrs is required implement the slog.Handler interface
+func (b Blog) WithAttrs(attrs []slog.Attr) slog.Handler {
+	var attributes []any
+	for _, a := range attrs {
+		attributes = append(attributes, a)
+	}
+	return b.With(attributes...)
+}
+
+// WithGroup is required implement the slog.Handler interface
+func (b Blog) WithGroup(string) slog.Handler {
+	return b
+}
+
+func (b Blog) Handle(_ context.Context, record slog.Record) error {
+	switch record.Level {
+	case slog.LevelDebug:
+		b.logger.Debug(join(b.prefix, record.Message))
+	case slog.LevelInfo:
+		b.logger.Info(join(b.prefix, record.Message))
+	case slog.LevelWarn:
+		b.logger.Warn(join(b.prefix, record.Message))
+	default:
+		b.logger.Error(join(b.prefix, record.Message))
+	}
+
+	return nil
+}
+
+// InstanceID creates an attribute from an instance ID
 func InstanceID(instanceID string) slog.Attr {
 	return slog.String(instanceIDLogKey, instanceID)
 }
 
+// BindingID creates an attribute from an binding ID
 func BindingID(bindingID string) slog.Attr {
 	return slog.String(bindingIDLogKey, bindingID)
 }

middlewares/api_version_header.go

@@ -30,7 +30,7 @@ const (
 )
 
 type APIVersionMiddleware struct {
-	Logger interface{ Error(string, ...any) }
+	Logger *slog.Logger
 }
 
 type ErrorResponse struct {