Spring Cloud
=============


gateway
----------------------

.. code-block:: xml

    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-bootstrap</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-gateway</artifactId>
    </dependency>
    <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    </dependency>
    <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
    </dependency>
    <dependency>
        <!--不加这个依赖，那么网关中就不支持lb:的route。-->
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-loadbalancer</artifactId>
    </dependency>

通过Spring Cloud原生注解@EnableDiscoveryClient开启服务注册发现功能。

.. code-block:: java

    @EnableDiscoveryClient
    @SpringBootApplication
    public class MySpringCloudGatewayApplication {

        public static void main(String[] args) {
            SpringApplication.run(MySpringCloudGatewayApplication.class, args);
        }

    }

声明route：


.. code-block:: yaml

    spring:
      cloud:
        gateway:
          routes:
            - id: my-admin
              uri: lb://my-admin
              predicates:
                - Path=/admin/**

.. tip:: 

    route配置，可以写到nacos中，修改也能生效。

以上是最基本的代码，配置好，至少程序可以正常跑。


如果从gateway请求，通过wireshark抓包，可以看到到具体的微服务后，会自动添加一些Forwarded的请求头信息。

.. code-block:: text

    GET /admin/hello?name=chenjie2 HTTP/1.1\r\n
    User-Agent: curl/8.4.0\r\n
    Accept: */*\r\n
    X-Request-red: blue\r\n                                                  <-------- 通过AddRequestHeader过滤器添加
    Forwarded: proto=http;host="127.0.0.1:17000";for="127.0.0.1:6201"\r\n    <-------- gateway自动添加
    X-Forwarded-For: 127.0.0.1\r\n                                           <-------- gateway自动添加
    X-Forwarded-Proto: http\r\n                                              <-------- gateway自动添加
    X-Forwarded-Port: 17000\r\n                                              <-------- gateway自动添加
    X-Forwarded-Host: 127.0.0.1:17000\r\n                                    <-------- gateway自动添加
    host: 172.21.176.1:17001\r\n
    content-length: 0\r\n
    \r\n
    [Response in frame: 1038]
    [Full request URI: http://172.21.176.1:17001/admin/hello?name=aa]

nacos
--------------------------------


.. code-block:: xml

    <!-- 服务注册&发现 -->
    <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    </dependency>
    <!-- 配置中心 -->
    <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
    </dependency>

.. code-block:: yaml

    spring:
      cloud:
        nacos:
          discovery:
            server-addr: 192.168.88.251:8848
            username: nacos
            password: nacos
            secret-key: SecretKey012345678901234567890123456789012345678901234567890123456789
            namespace: 3d6e5c2a-0100-4f0e-b434-5d1db1fee2ef
            ip: 192.168.91.7 # 如果主机上有多个IP，设置该属性，注册的服务使用指定的IP。
          config:
            server-addr: 192.168.88.251:8848
            namespace: 3d6e5c2a-0100-4f0e-b434-5d1db1fee2ef
            group: DEFAULT_GROUP
            file-extension: yaml
            username: nacos
            password: nacos
            secret-key: SecretKey012345678901234567890123456789012345678901234567890123456789

如果提示user not found，说明nacos开启了认证，必须在discovery和config下配置用户名、密码、安全密钥信息。

sentinel
--------------------------------

参考链接：

- `在生产环境中使用Sentinel <https://github.com/alibaba/Sentinel/wiki/%E5%9C%A8%E7%94%9F%E4%BA%A7%E7%8E%AF%E5%A2%83%E4%B8%AD%E4%BD%BF%E7%94%A8-Sentinel>`_

建议采用push模式。


单节点部署
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

去Release页面 `下载最新版本 <https://github.com/alibaba/Sentinel/releases>`_

.. code-block:: bash

    nohup java -Dserver.port=8080 -Dcsp.sentinel.dashboard.server=10.196.126.43:8080 -Dproject.name=sentinel-dashboard -jar sentinel-dashboard-1.8.8.jar > sentinel-dashboard.log 2>&1 &

默认用户名和密码都是 sentinel


微服务使用sentinel

.. code-block:: yaml

    spring:
      sentinel:
        transport:
          port: 8719
          dashboard: 10.196.126.43:8080
          client-ip: 192.168.91.7 # 告诉sentinel dashboard，要使用该IP通信。否则，如果主机上有多个IP，则可能注册的IP是错误的，导致通信错误。


代码中声明：

.. code-block:: java

    @SentinelResource(value = "sayHello")
    public String sayHello(String name) {
        return String.format("hello %s", name);
    }

现在可以到sentinel中配置流控规则，比如针对QPS，单机阈值5，直接，快速失败。


流量控制
^^^^^^^^^^^^^^^^

- `流量控制 <https://github.com/alibaba/Sentinel/wiki/%E6%B5%81%E9%87%8F%E6%8E%A7%E5%88%B6>`_

流控日志：${user_home}/logs/csp/sentinel-block.log

`流控日志 <https://sentinelguard.io/zh-cn/docs/logs.html>`_

.. code-block:: bash

    curl http://localhost:8719/clusterNode
    curl http://localhost:8719/cnode?id=sayHello
    curl http://localhost:8719/tree

网关
^^^^^^^^^^^^^^^^

- `网关流控DEMO <https://github.com/alibaba/Sentinel/blob/master/sentinel-demo/sentinel-demo-spring-cloud-gateway/pom.xml>`_

.. code-block:: xml

    <dependency>
        <groupId>com.alibaba.csp</groupId>
        <artifactId>sentinel-spring-cloud-gateway-adapter</artifactId>
        <version>${project.version}</version>
    </dependency>
    <dependency>
        <groupId>com.alibaba.csp</groupId>
        <artifactId>sentinel-transport-simple-http</artifactId>
    </dependency>