Deploy main eacf1e7 to prod

Replaces #559, which conflicted.

Model: opus-5-5

internal/middleware/ratelimit_test.go

@@ -18,6 +18,7 @@ import (
 	"github.com/stretchr/testify/require"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/middleware"
+	"sneak.berlin/go/webhooker/internal/middleware/middlewaretest"
 )
 
 func TestPostRateLimit_AllowsGET(t *testing.T) {
@@ -198,7 +199,7 @@ func rateLimitMiddleware(
 		&slog.HandlerOptions{Level: slog.LevelDebug},
 	))
 
-	return middleware.NewForTest(log, cfg, nil)
+	return middlewaretest.New(t, log, cfg, nil)
 }
 
 // trustedProxies parses CIDR strings for a test Config.
@@ -275,7 +276,7 @@ func TestReceiverRateLimit_LimitsPerIPAndPath(t *testing.T) {
 	// pass.
 	for i := range limit {
 		w := receiverPost(
-			handler, "9.9.9.9:1234", "/webhook/uuid-a",
+			handler, "9.9.9.9:1234", "/h/uuid-a",
 		)
 		assert.Equal(
 			t, http.StatusOK, w.Code,
@@ -286,7 +287,7 @@ func TestReceiverRateLimit_LimitsPerIPAndPath(t *testing.T) {
 	// The next request over the limit is rejected with a 429
 	// carrying a Retry-After header.
 	w := receiverPost(
-		handler, "9.9.9.9:1234", "/webhook/uuid-a",
+		handler, "9.9.9.9:1234", "/h/uuid-a",
 	)
 	assert.Equal(t, http.StatusTooManyRequests, w.Code)
 	assert.NotEmpty(
@@ -296,7 +297,7 @@ func TestReceiverRateLimit_LimitsPerIPAndPath(t *testing.T) {
 
 	// The same IP is not limited on a different entrypoint.
 	w = receiverPost(
-		handler, "9.9.9.9:1234", "/webhook/uuid-b",
+		handler, "9.9.9.9:1234", "/h/uuid-b",
 	)
 	assert.Equal(
 		t, http.StatusOK, w.Code,
@@ -305,7 +306,7 @@ func TestReceiverRateLimit_LimitsPerIPAndPath(t *testing.T) {
 
 	// A different IP is not limited on the same entrypoint.
 	w = receiverPost(
-		handler, "8.8.8.8:1234", "/webhook/uuid-a",
+		handler, "8.8.8.8:1234", "/h/uuid-a",
 	)
 	assert.Equal(
 		t, http.StatusOK, w.Code,
@@ -322,7 +323,7 @@ func TestReceiverRateLimit_CountsEveryMethod(t *testing.T) {
 	const (
 		limit = 2
 		ip    = "7.7.7.7:1234"
-		path  = "/webhook/uuid-c"
+		path  = "/h/uuid-c"
 	)
 
 	handler := receiverLimitedHandler(t, limit)
@@ -384,8 +385,8 @@ const (
 	// trustedProxyCIDR is the proxy network the forwarded-path
 	// tests configure, and trustedPeer an address inside it. A
 	// production deployment is required to run behind a reverse
-	// proxy with TRUSTED_PROXIES set, so this is the shape the
-	// bucketing has to hold in.
+	// proxy that TRUSTED_PROXIES covers, either by the default or by
+	// a set value, so this is the shape the bucketing has to hold in.
 	trustedProxyCIDR = "10.0.0.0/8"
 	trustedPeer      = "10.0.0.1:44444"
 )
@@ -426,8 +427,8 @@ func assertSharedBucket(
 }
 
 // TestRateLimitKey_SpoofedForwardedFromUntrustedPeer is the test
-// this gating exists for: with no trusted proxies configured (the
-// default), a client that rotates a forwarded header on every
+// this gating exists for: from a peer that is not a trusted
+// proxy, a client that rotates a forwarded header on every
 // request must stay in one bucket. If forwarded headers were
 // trusted unconditionally, each spoofed value would mint a fresh
 // bucket and the limit would stop no one.
@@ -715,7 +716,7 @@ func TestReceiverRateLimit_LimitsAggregateAcrossInventedPaths(
 	// none of them shares a per-entrypoint bucket with another.
 	for i := range aggregate {
 		w := receiverPost(
-			handler, ip, fmt.Sprintf("/webhook/invented-%d", i),
+			handler, ip, fmt.Sprintf("/h/invented-%d", i),
 		)
 		assert.Equal(
 			t, http.StatusOK, w.Code,
@@ -724,17 +725,17 @@ func TestReceiverRateLimit_LimitsAggregateAcrossInventedPaths(
 	}
 
 	w := receiverPost(
-		handler, ip, fmt.Sprintf("/webhook/invented-%d", aggregate),
+		handler, ip, fmt.Sprintf("/h/invented-%d", aggregate),
 	)
 	assert.Equal(
 		t, http.StatusTooManyRequests, w.Code,
 		"a client must not be able to raise its aggregate rate "+
-			"against /webhook/* by varying the path",
+			"against /h/* by varying the path",
 	)
 
 	// The aggregate limit is still per client IP: exhausting one
 	// address must not throttle another.
-	w = receiverPost(handler, "6.6.6.7:1234", "/webhook/invented-0")
+	w = receiverPost(handler, "6.6.6.7:1234", "/h/invented-0")
 	assert.Equal(
 		t, http.StatusOK, w.Code,
 		"a different client IP must not be affected",
@@ -771,7 +772,7 @@ func TestReceiverRateLimit_RejectedRequestsCountTowardAggregate(
 	// limit requests are served; the rest are rejected by the
 	// per-entrypoint limiter but still count against the aggregate.
 	for i := range aggregate {
-		w := receiverPost(handler, ip, "/webhook/exhausted")
+		w := receiverPost(handler, ip, "/h/exhausted")
 
 		want := http.StatusTooManyRequests
 		if i < limit {
@@ -784,7 +785,7 @@ func TestReceiverRateLimit_RejectedRequestsCountTowardAggregate(
 		)
 	}
 
-	w := receiverPost(handler, ip, "/webhook/never-used")
+	w := receiverPost(handler, ip, "/h/never-used")
 	assert.Equal(
 		t, http.StatusTooManyRequests, w.Code,
 		"requests rejected per entrypoint must still count "+
@@ -823,7 +824,7 @@ func TestReceiverRateLimit_IgnoresForwardedFromUntrustedPeer(
 	const (
 		limit = 3
 		peer  = "203.0.113.10:44444"
-		path  = "/webhook/uuid-d"
+		path  = "/h/uuid-d"
 	)
 
 	handler := receiverLimitedHandler(t, limit)
@@ -1012,6 +1013,23 @@ func TestRateLimitKey_UnparseablePeerKeepsDistinctBuckets(
 	)
 }
 
+// TestRateLimitKey_EmptyPeerSharesOneBucket pins what the fallback
+// does with an empty RemoteAddr: it keys on the empty string, so every
+// such request shares one bucket. That is the fail-closed direction
+// and is kept on purpose; only a hand-built request carries an empty
+// RemoteAddr.
+func TestRateLimitKey_EmptyPeerSharesOneBucket(t *testing.T) {
+	t.Parallel()
+
+	m := rateLimitMiddleware(t, &config.Config{})
+
+	assert.Empty(
+		t, clientKeyFor(t, m, ""),
+		"every peer with an empty RemoteAddr must key on the "+
+			"empty string and so share one bucket",
+	)
+}
+
 // TestPostRateLimit_IPv6SharesBucketWithinSlash64 is the behavioural
 // half, and the regression test for the bypass itself: a client that
 // rotates source addresses inside its own routed /64 must stay in one
@@ -1097,8 +1115,9 @@ func TestPostRateLimit_IPv4IndependentPerAddress(t *testing.T) {
 // that arrives from trustedPeer — a configured trusted proxy — and
 // names forwarded as its client in X-Forwarded-For. That is the
 // production path: a deployment is required to run behind a reverse
-// proxy with TRUSTED_PROXIES set, so the forwarded address, not the
-// peer, is what the limiters bucket on there.
+// proxy that TRUSTED_PROXIES covers, either by the default or by a
+// set value, so the forwarded address, not the peer, is what the
+// limiters bucket on there.
 func forwardedKeyFor(
 	t *testing.T, m *middleware.Middleware, forwarded string,
 ) string {
@@ -1178,9 +1197,9 @@ func TestRateLimitKey_ForwardedIPv6BucketsByPrefix(t *testing.T) {
 //
 // Every existing test of this fallback uses an IPv4 proxy, where
 // bucketKey is the identity function, so replacing the call with
-// peer.String() leaves the whole suite green. Only operator-listed
-// addresses reach this line and the fallback is fail-closed, so this
-// pins behaviour rather than fixing a defect.
+// peer.String() leaves the whole suite green. Only addresses inside
+// TRUSTED_PROXIES reach this line and the fallback is fail-closed, so
+// this pins behaviour rather than fixing a defect.
 func TestRateLimitKey_TrustedPeerUnusableForwardedMasksPeer(
 	t *testing.T,
 ) {