make NewStdLog take a level; log http span at DebugLevel like we did …

…for 2.4 in #8456

src/internal/dockertestenv/mysql.go

@@ -56,7 +56,7 @@ func newMySQLEphemeralURL(ctx context.Context, t testing.TB, name string) pachsq
 	db := testutil.OpenDBURL(t, u, MySQLPassword)
 	ctx, cf := context.WithTimeout(ctx, 30*time.Second)
 	defer cf()
-	mysql.SetLogger(log.NewStdLog(pctx.Child(pctx.TODO(), "ephemeral-mysql"))) //nolint:errcheck
+	mysql.SetLogger(log.NewStdLogAt(pctx.Child(pctx.TODO(), "ephemeral-mysql"), log.DebugLevel)) //nolint:errcheck
 	require.NoError(t, dbutil.WaitUntilReady(ctx, db))
 	testutil.CreateEphemeralDB(t, db, name)
 	u2 := u

src/internal/log/amazon.go

@@ -18,6 +18,6 @@ var _ aws.Logger = new(amazon)
 
 // NewAmazonLogger returns an aws.Logger.
 func NewAmazonLogger(ctx context.Context) aws.Logger {
-	a := amazon(*NewStdLog(ctx))
+	a := amazon(*NewStdLogAt(ctx, DebugLevel))
 	return &a
 }

src/internal/log/doc.go

@@ -202,12 +202,12 @@
 //
 //	NewAmazonLogger(ctx) # For the S3 client
 //	NewLogrus(ctx) # For logrus users, like dex and snowflake.
-//	NewStdLog(ctx) # For "log" users, like the net/http server.
+//	NewStdLogAt(ctx, [level]) # For "log" users, like the net/http server.
 //	AddLoggerToEtcdServer(ctx, server) # To add a logger to an in-memory etcd.
 //	AddLoggerToHttpServer(ctx, name, server) # To add a logger to incoming requests in a net/http server.
 //
-// Do not use a NewLogrus or a NewStdLog in any code you're writing.  They are only for third-party
-// packages.
+// Do not use a NewLogrus or a NewStdLogAt as the primary logger in any code you're writing.  They
+// are only for adapting to the needs of third-party packages.
 //
 // # EXTENDING THE LOGGING PACKAGE
 //

src/internal/log/http.go

@@ -18,7 +18,7 @@ func AddLoggerToHTTPServer(rctx context.Context, name string, s *http.Server) {
 	s.BaseContext = func(l net.Listener) context.Context {
 		return ctx
 	}
-	s.ErrorLog = NewStdLog(ctx)
+	s.ErrorLog = NewStdLogAt(ctx, DebugLevel)
 	if s.Handler != nil {
 		orig := s.Handler
 		s.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {

src/internal/log/stdlog.go

@@ -7,7 +7,11 @@ import (
 	"go.uber.org/zap"
 )
 
-// NewStdLog returns a *log.Logger (from the standard library "log" package) that logs to the provided context.
-func NewStdLog(ctx context.Context) *log.Logger {
-	return zap.NewStdLog(extractLogger(ctx).WithOptions(zap.AddCallerSkip(-1)))
+// NewStdLogAt returns a *log.Logger (from the standard library "log" package) that logs to the
+// provided context, at the provided level.
+func NewStdLogAt(ctx context.Context, lvl Level) *log.Logger {
+	// NewStdLogAt cannot return an error for any of the log levels that lvl.coreLevel()
+	// returns, since coreLevel will change the level to Debug if it's unknown.
+	l, _ := zap.NewStdLogAt(extractLogger(ctx).WithOptions(zap.AddCallerSkip(-1)), lvl.coreLevel()) //nolint:errcheck
+	return l
 }