test(e2e): add routing matcher module e2e test suite

Verify node-level routing matchers via a two-proxy relay: a forward
proxy whose only chain node carries matcher Host(`tcp-echo`) is only
eligible for a matching Host, so the request is relayed upstream to the
echo server; a non-matching Host is excluded (no eligible node) and never
reaches the echo server. Mirrors the resolver/ingress e2e pattern.

tests/e2e/routing_test.go

@@ -0,0 +1,81 @@
+package e2e
+
+import (
+	"context"
+	"io"
+	"testing"
+
+	"github.com/stretchr/testify/suite"
+	"github.com/testcontainers/testcontainers-go"
+)
+
+// RoutingSuite verifies node-level routing matchers. A forward proxy's only
+// chain node relays to an upstream proxy, but the node carries a matcher
+// Host(`tcp-echo`) so it is only eligible for requests whose Host matches. A
+// request to tcp-echo:5678 is matched, relayed upstream, and reaches the echo
+// server ("hello-gost"); a request to a non-matching host is excluded (no
+// eligible node) and never reaches the echo server.
+type RoutingSuite struct {
+	suite.Suite
+	ctx        context.Context
+	echoC      testcontainers.Container
+	proxyC     testcontainers.Container
+	upstreamC  testcontainers.Container
+}
+
+func (s *RoutingSuite) SetupSuite() {
+	s.ctx = context.Background()
+
+	echoC, err := RunEchoContainer(s.ctx, SharedNetworkName)
+	s.Require().NoError(err)
+	s.echoC = echoC
+
+	proxyC, err := RunGostContainerWithOptions(s.ctx, SharedNetworkName,
+		"testdata/routing/server.yaml", []string{"gost-proxy"}, []string{"8080/tcp"})
+	s.Require().NoError(err)
+	s.proxyC = proxyC
+
+	upstreamC, err := RunGostContainerWithOptions(s.ctx, SharedNetworkName,
+		"testdata/routing/upstream.yaml", []string{"gost-upstream"}, []string{"8081/tcp"})
+	s.Require().NoError(err)
+	s.upstreamC = upstreamC
+}
+
+func (s *RoutingSuite) TearDownSuite() {
+	for _, c := range []testcontainers.Container{s.proxyC, s.upstreamC, s.echoC} {
+		if c != nil {
+			c.Terminate(s.ctx)
+		}
+	}
+}
+
+// proxyRequest sends an HTTP GET to target through the matcher-gated proxy and
+// returns the response body.
+func (s *RoutingSuite) proxyRequest(target string) string {
+	cmd := []string{
+		"curl", "-s",
+		"-x", "http://gost-proxy:8080",
+		target,
+	}
+	_, out, err := s.echoC.Exec(s.ctx, cmd)
+	s.Require().NoError(err)
+	body, err := io.ReadAll(out)
+	s.Require().NoError(err)
+	return string(body)
+}
+
+// TestMatchedHost verifies that a request whose Host matches the node matcher is
+// relayed upstream and reaches the echo server.
+func (s *RoutingSuite) TestMatchedHost() {
+	s.Require().Contains(s.proxyRequest("http://tcp-echo:5678/"), "hello-gost")
+}
+
+// TestUnmatchedHost verifies that a request whose Host does not match the node
+// matcher is excluded (no eligible node) and never reaches the echo server.
+func (s *RoutingSuite) TestUnmatchedHost() {
+	s.Require().NotContains(s.proxyRequest("http://other.local:5678/"), "hello-gost")
+}
+
+func TestRoutingSuite(t *testing.T) {
+	suite.Run(t, new(RoutingSuite))
+}

tests/e2e/testdata/routing/server.yaml

@@ -0,0 +1,27 @@
+# Forward proxy gated by a node-level routing matcher. The only chain node is a
+# relay to an upstream proxy, but it is only eligible when the request Host
+# matches Host(`tcp-echo`). A request to tcp-echo:5678 matches, is relayed
+# upstream, and reaches the echo server ("hello-gost"); a request to any other
+# host is excluded (no eligible node) and never reaches the echo server.
+services:
+  - name: proxy
+    addr: ":8080"
+    handler:
+      type: http
+      chain: chain-0
+    listener:
+      type: tcp
+
+chains:
+  - name: chain-0
+    hops:
+      - name: hop-0
+        nodes:
+          - name: node-0
+            addr: gost-upstream:8081
+            matcher:
+              rule: 'Host(`tcp-echo`)'
+            connector:
+              type: http
+            dialer:
+              type: tcp

tests/e2e/testdata/routing/upstream.yaml

@@ -0,0 +1,9 @@
+# Upstream relay target for the routing matcher test: a plain forward proxy
+# that reaches the echo server directly.
+services:
+  - name: proxy
+    addr: ":8081"
+    handler:
+      type: http
+    listener:
+      type: tcp