feat: backend native executor implement

internal/hostnginx/config_test.go

@@ -0,0 +1,55 @@
+package hostnginx
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+)
+
+const serverConfiguration = `http {
+    upstream yms-server {
+        # yms-update managed upstream begin
+        # server 10.11.1.117:8080 max_fails=1 fail_timeout=2s;
+        server 10.11.1.117:8081 max_fails=1 fail_timeout=2s;
+        # yms-update managed upstream end
+    }
+}
+`
+
+func TestActiveBackendPortReadsExactManagedBlock(t *testing.T) {
+	port, err := ActiveBackendPort([]byte(serverConfiguration))
+	if err != nil || port != 8081 {
+		t.Fatalf("unexpected active backend port: port=%d err=%v", port, err)
+	}
+}
+
+func TestRenderBackendPortPreservesConfigurationAndSwitchesOneServer(t *testing.T) {
+	rendered, err := RenderBackendPort([]byte(serverConfiguration), 8080)
+	if err != nil {
+		t.Fatalf("render backend port: %v", err)
+	}
+	port, err := ActiveBackendPort(rendered)
+	if err != nil || port != 8080 {
+		t.Fatalf("unexpected rendered backend port: port=%d err=%v", port, err)
+	}
+	if !bytes.Contains(rendered, []byte("server 10.11.1.117:8080 max_fails=1 fail_timeout=2s;")) ||
+		!bytes.Contains(rendered, []byte("# server 10.11.1.117:8081 max_fails=1 fail_timeout=2s;")) {
+		t.Fatalf("rendered configuration does not contain exact server lines:\n%s", rendered)
+	}
+}
+
+func TestManagedBlockRejectsAmbiguousOrAlteredInput(t *testing.T) {
+	tests := map[string]string{
+		"both active":    strings.Replace(serverConfiguration, "# server 10.11.1.117:8080", "server 10.11.1.117:8080", 1),
+		"missing port":   strings.Replace(serverConfiguration, "        # server 10.11.1.117:8080 max_fails=1 fail_timeout=2s;\n", "", 1),
+		"changed option": strings.Replace(serverConfiguration, "max_fails=1", "max_fails=2", 1),
+		"extra line":     strings.Replace(serverConfiguration, managedEnd, "# unexpected\n        "+managedEnd, 1),
+	}
+	for name, content := range tests {
+		t.Run(name, func(t *testing.T) {
+			if _, err := ActiveBackendPort([]byte(content)); err == nil {
+				t.Fatal("expected altered managed block rejection")
+			}
+		})
+	}
+}