feat(ratelimit): Set RateLimit and RateLimit-Policy headers

internal/ratelimit/handler.go

@@ -11,6 +11,7 @@ import (
 	"regexp"
 
 	"github.com/hashicorp/boundary/globals"
+	"github.com/hashicorp/boundary/internal/errors"
 	"github.com/hashicorp/boundary/internal/event"
 	"github.com/hashicorp/boundary/internal/types/action"
 	"github.com/hashicorp/boundary/internal/types/resource"
@@ -155,6 +156,17 @@ func Handler(ctx context.Context, l *rate.Limiter, next http.Handler) http.Handl
 			return
 		}
 
+		l.SetUsageHeader(quota, rw.Header())
+		if err := l.SetPolicyHeader(res, a, rw.Header()); err != nil {
+			// Wrap error to emit an error event. An error here would be
+			// unexpected, since the only possible error would be
+			// ErrLimitPolicyNotFound which would have been returned by Allow
+			// and handled above. And even that would be unexpected, given how
+			// the limiter is initialized and the checks done by
+			// extractResourceAction.
+			errors.Wrap(ctx, err, op)
+		}
+
 		if !allowed {
 			rw.Header().Add("Retry-After", fmt.Sprintf("%.0f", quota.ResetsIn().Seconds()))
 			rw.WriteHeader(http.StatusTooManyRequests)

internal/ratelimit/handler_test.go

@@ -73,7 +73,10 @@ func TestHandler(t *testing.T) {
 			"127.0.0.1",
 			"authtoken",
 			http.StatusOK,
-			http.Header{},
+			http.Header{
+				"RateLimit-Policy": []string{`10;w=60;comment="total", 10;w=60;comment="ip-address", 10;w=60;comment="auth-token"`},
+				"RateLimit":        []string{`limit=10, remaining=9, reset=59`},
+			},
 		},
 		{
 			"AllowedCreate",
@@ -115,7 +118,10 @@ func TestHandler(t *testing.T) {
 			"127.0.0.1",
 			"authtoken",
 			http.StatusOK,
-			http.Header{},
+			http.Header{
+				"RateLimit-Policy": []string{`10;w=60;comment="total", 10;w=60;comment="ip-address", 10;w=60;comment="auth-token"`},
+				"RateLimit":        []string{`limit=10, remaining=9, reset=59`},
+			},
 		},
 		{
 			"AllowedRead",
@@ -157,7 +163,10 @@ func TestHandler(t *testing.T) {
 			"127.0.0.1",
 			"authtoken",
 			http.StatusOK,
-			http.Header{},
+			http.Header{
+				"RateLimit-Policy": []string{`10;w=60;comment="total", 10;w=60;comment="ip-address", 10;w=60;comment="auth-token"`},
+				"RateLimit":        []string{`limit=10, remaining=9, reset=59`},
+			},
 		},
 		{
 			"AllowedUpdate",
@@ -199,7 +208,10 @@ func TestHandler(t *testing.T) {
 			"127.0.0.1",
 			"authtoken",
 			http.StatusOK,
-			http.Header{},
+			http.Header{
+				"RateLimit-Policy": []string{`10;w=60;comment="total", 10;w=60;comment="ip-address", 10;w=60;comment="auth-token"`},
+				"RateLimit":        []string{`limit=10, remaining=9, reset=59`},
+			},
 		},
 		{
 			"AllowedDelete",
@@ -241,7 +253,10 @@ func TestHandler(t *testing.T) {
 			"127.0.0.1",
 			"authtoken",
 			http.StatusOK,
-			http.Header{},
+			http.Header{
+				"RateLimit-Policy": []string{`10;w=60;comment="total", 10;w=60;comment="ip-address", 10;w=60;comment="auth-token"`},
+				"RateLimit":        []string{`limit=10, remaining=9, reset=59`},
+			},
 		},
 		{
 			"AllowedAuthorizeSession",
@@ -283,7 +298,10 @@ func TestHandler(t *testing.T) {
 			"127.0.0.1",
 			"authtoken",
 			http.StatusOK,
-			http.Header{},
+			http.Header{
+				"RateLimit-Policy": []string{`10;w=60;comment="total", 10;w=60;comment="ip-address", 10;w=60;comment="auth-token"`},
+				"RateLimit":        []string{`limit=10, remaining=9, reset=59`},
+			},
 		},
 		{
 			"Limited",
@@ -334,7 +352,9 @@ func TestHandler(t *testing.T) {
 			"authtoken",
 			http.StatusTooManyRequests,
 			http.Header{
-				"Retry-After": []string{"60"},
+				"Retry-After":      []string{"60"},
+				"RateLimit-Policy": []string{`2;w=60;comment="total", 2;w=60;comment="ip-address", 2;w=60;comment="auth-token"`},
+				"RateLimit":        []string{`limit=2, remaining=0, reset=59`},
 			},
 		},
 		{