fix(traffic): 流量录制代理默认只监听 127.0.0.1，避免默认开放代理暴露 (#129) (#130)

traffic/proxy_test.go

@@ -57,3 +57,24 @@ func TestSetUpstreamProxyStoreClear(t *testing.T) {
 		t.Fatalf("invalid set mutated upstream to %v, want nil", got)
 	}
 }
+
+func TestProxyAddr(t *testing.T) {
+	cases := []struct {
+		addr string
+		want string
+	}{
+		// Bare :port means "bind all interfaces" — the legacy default. The URL
+		// agents consume must still point at loopback so they reach the local proxy.
+		{":8788", "http://127.0.0.1:8788"},
+		// Explicit loopback — the current default since #129 (open proxy exposure).
+		{"127.0.0.1:8788", "http://127.0.0.1:8788"},
+		// Explicit all-interface bind is still supported (remote capture via SSH).
+		{"0.0.0.0:8788", "http://0.0.0.0:8788"},
+	}
+	for _, c := range cases {
+		got := (&Traffic{addr: c.addr}).ProxyAddr()
+		if got != c.want {
+			t.Errorf("ProxyAddr(%q) = %q, want %q", c.addr, got, c.want)
+		}
+	}
+}

traffic/traffic.go

@@ -200,8 +200,14 @@ func hostOnly(hostport string) string {
 	return hostport
 }
 
-// ProxyAddr returns the address workers should set as HTTP(S)_PROXY.
-func (t *Traffic) ProxyAddr() string { return "http://127.0.0.1" + t.addr }
+// ProxyAddr returns the address workers should set as HTTP(S)_PROXY. A bare
+// ":port" means "bind all interfaces" (legacy default), so map it to loopback.
+func (t *Traffic) ProxyAddr() string {
+	if strings.HasPrefix(t.addr, ":") {
+		return "http://127.0.0.1" + t.addr
+	}
+	return "http://" + t.addr
+}
 
 // SetUpstreamProxy points every captured request at a global egress proxy
 // (http/https/socks5, optional user:pass in the URL). An empty raw string clears