1. gateway

1.  Gateway is also called inter network connector 、 Protocol converter , Realize network interconnection above the network layer , It is only applicable to the interconnection of two networks with different high-level protocols ;

2. stay OCI In terms of the agreement ： Gateways fall into two categories , One is a connection oriented gateway , One is a connectionless gateway ;
3. stay TCP In terms of the agreement , A gateway to another network is essentially an address IP Address ; The hosts of different networks are in different networks , To achieve communication , You have to go through the gateway . It's the only one with a gateway set up IP Address ,TCP/IP In order to realize the mutual communication between different networks .

2.API gateway

API A gateway is a server , It's the only access to the system ,API The gateway encapsulates the internal architecture of the system , It provides a customized interface for the client API.Spring Cloud Gateway It is a simple and effective unified method for microservice architecture API Routing management

3. The functions that the gateway should have

1. performance ：API High availability 、 Load balancing , Fault tolerance mechanism
2. Security ： Authority authentication 、 desensitization 、 Flow cleaning 、 Back end signature （ Ensure that the whole link is trusted to call ）, The blacklist （ Restrictions on illegal calls ）
3. journal ： logging , When it comes to distributed , Full link tracking is essential
4. cache ： Data caching
5. monitor ： Record request response data ,api Time consuming analysis , Performance monitoring
6. Current limiting ： flow control , Staggered flow control , It can be defined as a variety of current limiting rules

1. Gateway dimension ： For a micro service as a whole
   Coarse grained ： Global configuration
2. API Grouped dimensions ： For a range of URL Address , It can not be in a micro service
   Fine granularity ： Local configuration
   Add dependency ：

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
</dependency>
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-alibaba-sentinel-gateway</artifactId>
</dependency>

Modify the configuration file application.yml：

 sentinel:
      filter:
        enabled: true
      datasource:
        ds1.file:
          file: classpath:router-flow.json
          ruleType: gw-flow
        ds2.file:
          file: classpath:api-flow.json #api-flow.json  Grouping of interfaces 
          ruleType: gw_api_group

Add current limiting rule gw-flow.json

[
  {
    
    "resource": " The name of the resource ： Gateway time routes.id,api grouping ：api Name of the group ",//
    "resourceMode": 0 , //0 It's the gateway ,1 yes 
    "count": 2,
    "intervalSec": 60 // timer 
  },
  // Here is an example 
  {
    
    "resource": "admin-service-api",
    "resourceMode":"1",
    "count": 1,
    "intervalSec": 60
  }
]

add to api-group.json

[
  {
    
    "apiName": "admin-service-api",
    "predicateItems": [
      {
    
        "pattern": "/admin/login"
      }
    ]
  }
]

add to Controller Get current limiting rules

@RestController
public class FlowRulesController {
    

    @GetMapping("/gw/flow/rules")
    public Set<GatewayFlowRule> getGatewayFlowRules(){
    
        return GatewayRuleManager.getRules() ;
    }

    @GetMapping("/gw/api/groups")
    public Set<ApiDefinition> getApiGroupRules(){
    
        return GatewayApiDefinitionManager.getApiDefinitions();
    }
}

• The data source of dynamic rules used ( Use nacos To configure )

    sentinel:
      transport:
        dashboard: sentinel-server:8858  # sentinel-dashboard  Put it in ecs  Inside 
      datasource:
#        ds1.file:
#          file: classpath:gw-flow.json  #  gateway  + API Current limiting of packets 
#          ruleType: gw_flow
         ds1.nacos: #com.alibaba.csp.sentinel.datasource.nacos.NacosDataSource  Use Nacos Perpetuate my sentinel  Data time , Need to add nacos-datasource Dependence 
           serverAddr: nacos-server:8848
           dataId: gw-flow
           ruleType: gw_flow
#
#        ds2.file:
#          file: classpath:api-group.json
#          ruleType: gw_api_group
         ds2.nacos:
           serverAddr: nacos-server:8848
           dataId: api-group
           ruleType: gw_api_group

Use nacos Persistence rules , Need to add dependencies

<dependency>
    <groupId>com.alibaba.csp</groupId>
    <artifactId>sentinel-datasource-nacos</artifactId>
</dependency>

7. Grayscale ： Online grayscale deployment , Can reduce the risk
8. route ： Dynamic routing rules

4. nginx And gatewau The difference between ：

1.nginx, As the gateway of the whole global , It's external , Out of the outermost ;gateway, More like a business gateway , It is mainly used to provide services for different clients , For aggregating business . Each micro service is deployed independently , Single responsibility , When providing external services, you need to have something to aggregate the business
2.nginx It's written in different languages , Should not be associated with expansion , and gateway It's different , It's like java Written , Easy to extend and maintain

5. Use Spring Cloud Gateway

1. stay gateway-server Add 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>

2. stay gateway-server Add a startup class

@SpringBootApplication
@EnableDiscoveryClient
public class GatewayServerApplication {
    

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

3. stay gateway-server Add configuration files to it

server:
  port: 80
spring:
  application:
    name: gateway-server
  cloud:
    nacos:
      discovery:
        server-addr: nacos-server:8848 #  Modify the host  file 
    gateway:
      discovery:
        locator:
          enabled: true
          lower-case-service-id: true # admin-service ADMIN-SERVICE  /admin-service/** ->  Microservices （ADMIN-SERVICE） routes: - id: admin-service_router uri: lb://admin-service #  Forward to that destination  predicates: - Path=/admin/** filters: - StripPrefix=1 #  Current end access /admin/login - >login  take admin Automatically remove  - id: member-service_router uri: lb://member-service #  Forward to that destination  predicates: - Path=/user/** filters: - StripPrefix=1 #  Current end access /user/login - >login  take user Automatically remove  - id: finance-service_router uri: lb://finance-service #  Forward to that destination  predicates: - Path=/finance/** filters: - StripPrefix=1 #  Current end access /finance/xx, Get rid of finance - id: exchange-service_router #  Routing of trading system  uri: lb://exchange-service #  Forward to that destination  predicates: - Path=/exchange/** filters: - StripPrefix=1 #  Current end access /exchange/xx,exchange - id: test_router uri: http://www.aliyun.com predicates: - Path=/product # /test->http://www.baidu.com  The gateway itself will build a request to access the address we want to access  GET:http://www.baidu.com/test #  Through the gateway to complete 2  Current limiting of three dimensions ：  Gateway dimension  + API  grouping  sentinel: transport: dashboard: sentinel-server:8858 # sentinel-dashboard  Put it in ecs  Inside  datasource: # ds1.file: # file: classpath:gw-flow.json #  gateway  + API Current limiting of packets  # ruleType: gw_flow ds1.nacos: #com.alibaba.csp.sentinel.datasource.nacos.NacosDataSource  Use Nacos Perpetuate my sentinel  Data time , Need to add nacos-datasource Dependence  serverAddr: nacos-server:8848 dataId: gw-flow ruleType: gw_flow # # ds2.file: # file: classpath:api-group.json # ruleType: gw_api_group ds2.nacos: serverAddr: nacos-server:8848 dataId: api-group ruleType: gw_api_group #  We demonstrated sentinel-dashboard  The definition of rules , And when the rules are defined , Our gateway can immediately sense （ take effect ）（nacos Can't perceive ）, But next time we restart , Will lose the rules .--》nacos redis: host: redis-server port: 6380 password: Ltd3411??