MCP Gateway in Action: Zero-Code Tool Extension with Higress + Nacos

Honghao Wang

01 Dec 2025 — 4 min read

AliMei Editorial Introduction

This article presents a privatized MCP intelligent agent gateway architecture using open‑source Higress and Nacos. It enables:

Dynamic tool registration
Real-time Prompt updates
Multi-tenant security isolation
One-click production deployment without public internet or Helm

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Background

With the rapid emergence of AI assistants leveraging RAG and intelligent Q&A, traditional Q&A alone falls short for enterprise use. We require assistants that directly invoke APIs and system interfaces, functioning as intelligent agents.

We chose MCP as the communication protocol between models and interfaces due to its growing adoption. When designing an MCP Server for enterprise services, key challenges include:

Session maintenance via SSE in high-availability multi-instance deployments
Dynamic Prompt updates for faster iteration
Authorization isolation for multi-tenant cloud environments

Higress solves challenge 1, offering rich monitoring and a visual console.

Nacos addresses challenge 2 by serving as an MCP registry to store service and tool metadata.

Deployment flow:

Higress = MCP Proxy
Nacos = MCP Registry

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Architecture Overview

Both components are cloud-native and run in Kubernetes. In isolated production environments (no internet), we use community versions of Higress and Nacos and deploy directly via Docker images without Helm.

Advantages:

Zero-code tool extension
Fast Prompt update & verification through visual console
Tenant isolation via Nacos namespaces

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Private Deployment of Higress

Deployment Methods

Higress supports:

Helm
docker-compose
All-in-one Docker image

In restricted environments, we use all-in-one Docker (`Dockerfile`) to deploy all processes inside a single pod, scaling via multiple replicas.

FROM higress-registry.cn-hangzhou.cr.aliyuncs.com/higress/all-in-one:latest

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WASM Plugin Download Issue

Direct image deployment may fail due to WASM plugin download via OCI.

MCP in Higress depends on WASM plugins, so we must address this.

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WASM Plugin Independent Deployment

The plugin-server project enables HTTP-based private plugin distribution. Benefits:

Avoids network dependency on public OCI registries
Improves plugin load time

Step 1 – Deploy `plugin-server`

FROM higress-registry.cn-hangzhou.cr.aliyuncs.com/higress/plugin-server:1.0.0

Step 2 – Create K8s Service (ClusterIP)

apiVersion: v1
kind: Service
metadata:
  name: higress-plugin-server
  namespace: higress-system
spec:
  type: ClusterIP
  ports:
    - port: 80
      targetPort: 8080
  selector:
    app: higress-plugin-server

> Tip: In Kubernetes, service DNS follows

> `..svc.cluster.local`

Step 3 – Update Plugin Download URL in Higress

ENV HIGRESS_ADMIN_WASM_PLUGIN_CUSTOM_IMAGE_URL_PATTERN=http://[K8s service address]/plugins/${name}/${version}/plugin.wasm
ENV MCP_SERVER_WASM_IMAGE_URL=http://[K8s service address]/plugins/mcp-server/1.0.0/plugin.wasm

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Once configured, redeploy. Verify ports 8080 and 8443 are active.

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Configuration Sync Limitation

With all-in-one deployment inside pods:

Each pod runs independently
Built-in console config changes affect only one instance
Config files must be stored in project code and redeployed when updated

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Sticky Sessions in MCP

For SSE communication, Higress + Redis handles sticky sessions.

Example config:

mcpServer:
  enable: true
  sse_path_suffix: /sse
  redis:
    address: xxx.redis.zhangbei.rds.aliyuncs.com:6379
    username: ""
    password: "xxx"
    db: 0

Redis monitoring:

PSUBSCRIBE mcp-server-sse:*

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Custom Image Build

Official Higress images are minimal. To add enterprise tools like Alibaba Cloud SLS:

Copy all-in-one Dockerfile contents
Add extra build steps and dependencies
Update plugin paths if needed
Ensure glibc ≥ 2.18 for `envoy`

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External Access Modes

Internal Console Access (8001): View configs, no editing
External MCP Gateway Access (8080): Public client connections

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Full Dockerfile Example

FROM [Enterprise Base Image]
# Higress all-in-one build steps...

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Nacos Deployment

Deploy via:

`nacos-operator` (K8s)
Direct Docker image

FROM nacos-registry.cn-hangzhou.cr.aliyuncs.com/nacos/nacos-server:latest

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Cluster Deployment

Nacos uses Raft; requires ≥3 instances.

Static config example:

ENV MODE=cluster
ENV NACOS_SERVERS="10.0.0.1:8848 10.0.0.2:8848 10.0.0.3:8848"

> Note: Static IPs are unsuitable in cloud-native environments; use dynamic discovery.

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Dynamic Discovery via Headless Service

Create headless K8s service:

clusterIP: None
ports:
  - port: 8848
selector:
  app: mcp-nacos

Implement script to dynamically update `cluster.conf` via `nslookup` service FQDN.

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External MySQL Config

Cluster mode requires MySQL:

ENV SPRING_DATASOURCE_PLATFORM=mysql
ENV MYSQL_SERVICE_HOST=xxx.mysql.zhangbei.rds.aliyuncs.com
ENV MYSQL_SERVICE_DB_NAME=nacos
ENV MYSQL_SERVICE_USER=xxx
ENV MYSQL_SERVICE_PASSWORD=xxx

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Higress–Nacos Connection Service

Expose ports 8848 and 9848 in K8s Service for gRPC config pulls.

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Authentication Approach

We reuse existing service-level authentication rather than implementing all in Higress, to:

Lower maintenance overhead
Avoid storing sensitive keys in gateway layer

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MCP End-to-End Verification

Step 1 – Register Service & Tool in Nacos

curl -X POST 'http://127.0.0.1:8848/nacos/v1/ns/instance?...'

Step 2 – Configure MCP Source in Higress

Disable auth for quick test.

Step 3 – Connect from Cursor or Cherry Studio

Use Higress MCP gateway URL and test tool invocation.

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Diagrams

Disaster Recovery Architecture

Tools routed via URIs for isolation.

Logical Module Diagram

Multiple authentication logics coexist without conflict.

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References

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Nacos 2.4.0 Release Notes

Highlights

Config Center: Faster large-scale pushes, lower resource consumption
Service Discovery: Improved heartbeat, gateway-friendly APIs
Security: TLS mutual auth, failover enhancements, ACL refinements
Bug Fixes: High-concurrency refresh fixes, ephemeral deregistration fixed

Upgrade Steps:

Backup configs and storage
Update `nacos.properties`
Validate heartbeat/push settings
Test dependent services

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Resources

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In Summary:

This guide covers private deployment of Higress & Nacos for MCP, solving plugin isolation, sticky sessions, dynamic service discovery, and multi-tenant auth. By combining these with cloud-native patterns, enterprises can deliver secure AI-driven gateways completely offline.