refactor: simplify Node SSR parsing and validation

internal/hostnginx/nodessr.go

@@ -99,36 +99,48 @@ func parseNodeSsrBlock(content []byte) (nodeSsrBlock, error) {
 	servers := make([]nodeSsrServer, 0, 2)
 	seen := make(map[int]struct{}, 2)
 	for index := begin + 1; index < end; index++ {
-		trimmed := strings.TrimSpace(lines[index])
-		commented := strings.HasPrefix(trimmed, "# server ")
-		active := strings.HasPrefix(trimmed, "server ")
-		if !commented && !active {
-			if trimmed != "" {
-				return nodeSsrBlock{}, fmt.Errorf("managed Node SSR upstream contains an unexpected line: %q", trimmed)
-			}
+		server, found, err := parseNodeSsrServer(lines[index], index)
+		if err != nil {
+			return nodeSsrBlock{}, err
+		}
+		if !found {
 			continue
 		}
-		serverText := strings.TrimPrefix(trimmed, "# ")
-		fields := strings.Fields(serverText)
-		if len(fields) != 4 || fields[0] != "server" || fields[2] != "max_fails=1" || fields[3] != "fail_timeout=2s;" {
-			return nodeSsrBlock{}, fmt.Errorf("managed Node SSR upstream server line has an unsupported format: %q", trimmed)
+		if _, exists := seen[server.port]; exists {
+			return nodeSsrBlock{}, fmt.Errorf("managed Node SSR upstream contains duplicate port %d", server.port)
 		}
-		_, portText, err := net.SplitHostPort(fields[1])
-		if err != nil {
-			return nodeSsrBlock{}, fmt.Errorf("parse managed Node SSR upstream address %q: %w", fields[1], err)
-		}
-		port, err := strconv.Atoi(portText)
-		if err != nil || (port != nodeSsrPort18910 && port != nodeSsrPort28910) {
-			return nodeSsrBlock{}, fmt.Errorf("managed Node SSR upstream contains unsupported port %q", portText)
-		}
-		if _, exists := seen[port]; exists {
-			return nodeSsrBlock{}, fmt.Errorf("managed Node SSR upstream contains duplicate port %d", port)
-		}
-		seen[port] = struct{}{}
-		servers = append(servers, nodeSsrServer{line: index, port: port, commented: commented})
+		seen[server.port] = struct{}{}
+		servers = append(servers, server)
 	}
 	if len(servers) != 2 {
 		return nodeSsrBlock{}, fmt.Errorf("managed Node SSR upstream must contain exactly two servers, got %d", len(servers))
 	}
 	return nodeSsrBlock{lines: lines, servers: servers}, nil
 }
+
+// parseNodeSsrServer parses one server line inside the managed Node SSR block.
+func parseNodeSsrServer(line string, lineIndex int) (nodeSsrServer, bool, error) {
+	trimmed := strings.TrimSpace(line)
+	commented := strings.HasPrefix(trimmed, "# server ")
+	active := strings.HasPrefix(trimmed, "server ")
+	if !commented && !active {
+		if trimmed != "" {
+			return nodeSsrServer{}, false, fmt.Errorf("managed Node SSR upstream contains an unexpected line: %q", trimmed)
+		}
+		return nodeSsrServer{}, false, nil
+	}
+	serverText := strings.TrimPrefix(trimmed, "# ")
+	fields := strings.Fields(serverText)
+	if len(fields) != 4 || fields[0] != "server" || fields[2] != "max_fails=1" || fields[3] != "fail_timeout=2s;" {
+		return nodeSsrServer{}, false, fmt.Errorf("managed Node SSR upstream server line has an unsupported format: %q", trimmed)
+	}
+	_, portText, err := net.SplitHostPort(fields[1])
+	if err != nil {
+		return nodeSsrServer{}, false, fmt.Errorf("parse managed Node SSR upstream address %q: %w", fields[1], err)
+	}
+	port, err := strconv.Atoi(portText)
+	if err != nil || (port != nodeSsrPort18910 && port != nodeSsrPort28910) {
+		return nodeSsrServer{}, false, fmt.Errorf("managed Node SSR upstream contains unsupported port %q", portText)
+	}
+	return nodeSsrServer{line: lineIndex, port: port, commented: commented}, true, nil
+}

internal/transaction/node_ssr_container_deployment.go

@@ -88,9 +88,17 @@ func validateNodeSsrContainerDeployment(deployment NodeSsrContainerDeployment) e
 	if deployment.ActivePort != 18910 && deployment.ActivePort != 28910 {
 		return fmt.Errorf("Node SSR container deployment port must be 18910 or 28910: %d", deployment.ActivePort)
 	}
-	for name, value := range map[string]string{"container name": deployment.ContainerName, "image digest": deployment.ImageDigest, "container ID": deployment.ContainerID} {
-		if value == "" || strings.TrimSpace(value) != value {
-			return fmt.Errorf("exact Node SSR container %s is required", name)
+	fields := []struct {
+		name  string
+		value string
+	}{
+		{name: "container name", value: deployment.ContainerName},
+		{name: "image digest", value: deployment.ImageDigest},
+		{name: "container ID", value: deployment.ContainerID},
+	}
+	for _, field := range fields {
+		if field.value == "" || strings.TrimSpace(field.value) != field.value {
+			return fmt.Errorf("exact Node SSR container %s is required", field.name)
 		}
 	}
 	return nil