Zero. Premise of use

Create an aggregation project in which each module is an independent springboot project

The springcloud version should correspond to the springboot version, otherwise an error will be reported

1, Introduction to components used

assembly	effect
nacos	Registry (service registration and discovery), configuration center (dynamic configuration management)
Ribbon	load balancing
Feign	Declarative Http client (calling remote services)
Sentinel	Service fault tolerance (current limiting, degradation, fusing)
Gateway	API gateway (weblux programming mode)
Sleuth	Call chain monitoring
Seata	Original Fescar, i.e. distributed transaction solution

2, Introducing dependencies in common modules

1. Each microservice project will have a common module to introduce some common dependencies and configurations
2. When this dependency is introduced, other dependencies of spring cloud Alibaba do not need to write the version number
3. Note that the version number should correspond to the springboot version

<dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.2.3.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

3, Nacos

1. Download nacos and start

Link: https://github.com/alibaba/nacos/releases

Open the downloaded folder and click Startup in bin CMD run

2. Registration Center

Public module introduces registry dependency

<dependency>
     <groupId>com.alibaba.cloud</groupId>
     <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>

1. Specify the nacos address and service name in each micro service yml (to know which service is registered)

spring:
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
  application:
    name: mall-coupon

2. Use the @ EnableDiscoveryClient annotation to enable service registration and discovery

After joining, you can register with the registration center

Visit Nacos at http://127.0.0.1:8848/nacos The account and password are all Nacos

You can see that the service has been registered

3. Configuration center

1. Import dependency

Import dependency in common module

  <dependency>
      <groupId>com.alibaba.cloud</groupId>
      <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
  </dependency>

2. Create a new bootstrap yml

Priority is higher than application yml

spring:
  application:
    name: mall-coupon
  cloud:
    nacos:
      config:
        server-addr: 127.0.0.1:8848

3. Test the original configuration

1. In application YML new value added

2. @ Value get Value

3. Interface output value

@RestController
@RequestMapping("/coupon")
public class couponController {
	@Value("${nacosConfigTest.name}")
	private String name;
	@Value("${nacosConfigTest.value}")
	private String value;

	@Resource
	MemberFeignService memberFeignService;

	@GetMapping("/test")
	public String  test(){
		String s = memberFeignService.memberFeignTest();
		String result = "This is the return interface of the caller module calling the callee module:"+s;
		return result;
	}


	@GetMapping("/configTest")
	public String configTest(){
		return "Value obtained:"+name+":"+value;
	}

}

4. The value obtained by the interface at this time

4. nacos new configuration

1. New configuration

2. Input the information that needs dynamic configuration into the configuration content

3. Use @ RefreshScope on the interface class

4. At this point, the interface return value becomes dynamic configuration

4. Namespace (configuration isolation)

By default, all new configurations are in the public space

For example, during development, we have 1, development environment 2, deployment environment 3 and test environment

1. Add a new development, deployment and test environment in the nacos namespace
2. Click the configuration list to add several environments

3. Create the same configuration as above in the dev environment
4. In bootstrap YML new namespace

spring:
  application:
    name: mall-coupon
  cloud:
    nacos:
      config:
        server-addr: 127.0.0.1:8848
        file-extension: yaml #Specify yml file
        namespace: e9b627cb-44b1-480e-a46e-2ea019fe2656  # Namespace id

5. At this time, the configuration in the test environment is taken

5. Configure grouping

1. Fill in groups when adding configurations
2. In bootstrap YML add specified group

spring:
  application:
    name: mall-coupon
  cloud:
    nacos:
      config:
        server-addr: 127.0.0.1:8848
        file-extension: yaml #Specify yml file
        namespace: e9b627cb-44b1-480e-a46e-2ea019fe2656  # Namespace id
        group: test  #Group name

3. In this case, the value of the specified group is taken

4, Feign declarative remote call

1. Public module introduces openfeign dependency

   <dependency>
         <groupId>org.springframework.cloud</groupId>
         <artifactId>spring-cloud-starter-openfeign</artifactId>
         <version>2.2.9.RELEASE</version>
   </dependency>

2. The interface is normally written in one module and called by another module

1. The member module (called module) writes the interface normally

2. coupon module (calling module) creates a feign package and an interface class to specifically call the interface of member module

3. Use @ feignclient ("mall member") on the interface class to specify the service name on nacos

4. Write the interface path of the full member module (called module)

3. Use @ EnableFeignClients on the calling module startup class to open feign

The coupon module (caller) opens feign and specifies the package name

Test call

4. feign performance optimization

Feign's underlying client implementation:
1. URLConnection: the default implementation does not support connection pool
2. Apache HttpClient: support connection pool
3. OKHttp: support connection pool

Therefore, optimizing feign mainly includes:
1. Use the connection pool instead of the default URLConnection
2. Log level, preferably basic or none

Introduce dependency

 <dependency>
     <groupId>io.github.openfeign</groupId>
     <artifactId>feign-httpclient</artifactId>
 </dependency>

Configure yml

feign:
  client:
    config:
      default: # default global configuration
        loggerLevel: BASIC #At the log level, BASIC is the most BASIC request and response information
  httpclient:
    enabled: true # Switch supporting httpClient
    max-connections: 200 #maximum connection
    max-connections-per-route: 50 # Maximum connections per path

5, Gateway gateway

Common functions: route forwarding, permission verification, current limit control, etc

1. Build

1. New gateway module

2. Rely on

<!--  Common module-->
 <dependency>
     <groupId>com.example.mall</groupId>
     <artifactId>mall-common</artifactId>
     <version>0.0.1-SNAPSHOT</version>
 </dependency>
 <!--  gateway-->
 <dependency>
     <groupId>org.springframework.cloud</groupId>
     <artifactId>spring-cloud-starter-gateway</artifactId>
     <version>2.2.9.RELEASE</version>
 </dependency>

3. @ EnableDiscoveryClient enable service registration

4. Create a new bootstrap YML and application yml

bootstrap.yml

spring:
  application:
    name: mall-gateway
  cloud:
    nacos:
      config:
        server-addr: 127.0.0.1:8848
        namespace: 6d405b31-5f62-4105-b8a6-339cc0b8464e

application.yml

server:
  port: 88
spring:
  application:
    name: mall-gateway
  cloud:
    nacos:
      config:
        server-addr: 127.0.0.1:8848

5. New gateway namespace and configuration

6. Exclude data source related configurations

Because we have introduced the common module, the gateway does not need to configure the data source, and it is not ruled out that the data source configuration will report an error

2. New forwarding gateway configuration (yml)

server:
  port: 88
spring:
  application:
    name: mall-gateway
  cloud:
    nacos:
      config:
        server-addr: 127.0.0.1:8848
    #Gateway configuration
    gateway:
      routes:
        - id: coupon
          uri: http://127.0.0.1:8881 / # request address to go
         # uri: lb://The target address lb of the mall coupling # route is load balancing, followed by the service name
          predicates:  # Routing assertion is to judge whether the request meets the conditions of routing rules
            - Query=url,coupon      # If the URL has / coupon, go to the uri address above. For example: url=coupon
           # - Path=/coupon/**      # This url is matched according to the path. It meets the requirements as long as it starts with / coupon
		   #- After=2037-01-20T17:42:47.789-07:00[Asia/Shanghai]  # You can access it after this time
			
        - id: member
          uri: http://127.0.0.1:8882 / # request address to go
          # uri: lb://The target address lb of the mall member # route is load balancing, followed by the service name
          predicates: # Routing assertion is to judge whether the request meets the conditions of routing rules
            - Query=url,member    # If the URL has / coupon, go to the upper uri address url=member
           # - Path=/member/**      # This url is matched according to the path. It meets the requirements as long as it starts with / member

test

Spring provides 11 basic predict factories:

name	explain	Example
After	Is a request after a certain point in time	- After=2037-01-20T17:42:47.789-07:00[America/Denver]
Before	Is a request before a certain point in time	- Before=2031-04-13T15:14:47.433+08:00[Asia/Shanghai]
Between	Is a request before two points in time	- Between=2037-01-20T17:42:47.789-07:00[America/Denver], 2037-01-21T17:42:47.789-07:00[America/Denver]
Cookie	The request must contain some cookie s	- Cookie=chocolate, ch.p
Header	The request must contain some header s	- Header=X-Request-Id, \d+
Host	The request must be to access a host (domain name)	- Host=.somehost.org,.anotherhost.org
Method	The request mode must be the specified mode	- Method=GET,POST
Path	The request path must conform to the specified rules	- Path=/red/{segment},/blue/**
Query	The request parameter must contain the specified parameter	-Query=name, Jack or - Query=name
RemoteAddr	The ip address of the requester must be in the specified range	- RemoteAddr=192.168.1.1/24
Weight	Weight processing

3. Route filter GatewayFilterFactory

spring provides 31 different routing filter factories.

name	explain
AddRequestHeader	Add a request header to the current request
RemoveRequestHeader	Remove a request header from the request
AddResponseHeader	Add a response header to the response result
RemoveResponseHeader	There is a response header removed from the response result
RequestRateLimiter	Limit requested traffic
. . .

test
1. Add configuration
2. Get request header in interface
3. Added to request header
4. Effective for all routing requests
5. Code

server:
  port: 88
spring:
  application:
    name: mall-gateway
  cloud:
    nacos:
      config:
        server-addr: 127.0.0.1:8848
    #Gateway configuration
    gateway:
      routes:
        - id: coupon
          uri: http://127.0.0.1:8881 / # request address to go
         # uri: lb://The destination address lb of the coupon # route is load balancing, followed by the service name
          predicates:  # Routing assertion is to judge whether the request meets the conditions of routing rules
            #- Query=url,coupon      # If the URL has / coupon, go to the uri address above. For example: url=coupon
            - Path=/coupon/**      # This url is matched according to the path. It meets the requirements as long as it starts with / coupon
            #- After=2037-01-20T17:42:47.789-07:00[Asia/Shanghai]  # You can access it after this time
          #filters: #filter
            #- AddRequestHeader=Truth,niubi!  #Add request header

        - id: member
          uri: http://127.0.0.1:8882 / # request address to go
          # uri: lb://The target address lb of the member # route is load balancing, followed by the service name
          predicates: # Routing assertion is to judge whether the request meets the conditions of routing rules
            #- Query=url,member    # If the URL has / coupon, go to the upper uri address url=member
            - Path=/member/**      # This url is matched according to the path. It meets the requirements as long as it starts with / member

      default-filters: #The default filter will take effect for all routing requests
        - AddRequestHeader=Truth,niubi!

4. Global filter

The difference between GetewayFilter and GetewayFilter is that GetewayFilter is defined through configuration, and the processing logic is fixed. The logic of GlobalFilter needs to be implemented by writing code.
This is defined by implementing the GlobalFilter interface.

Case: define global filter, intercept and judge user identity
Requirement: define a global filter, intercept the request, and judge whether the requested parameters meet the following conditions:
1. Is there authorization in the parameter
2. Whether the authorization parameter value is admin
If both are met, release, otherwise intercept

@Order(-1)  // Multiple filters, the smaller the value, the higher the priority
@Component
public class AuthorizationFilter implements GlobalFilter {
	@Override
	public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
		// 1. Get request header
		ServerHttpRequest request = exchange.getRequest();
		MultiValueMap<String, String> params = request.getQueryParams();
		// 2. Gets the authorization parameter in the parameter
		String auth = params.getFirst("authorization");
		// 3. Judge whether the parameter value is equal to admin
		if ("admin".equals(auth)){
			// 4. Yes, release
			return	chain.filter(exchange);
		} // 5. No, intercept
		// Set status code
		exchange.getResponse().setStatusCode(HttpStatus.UNAUTHORIZED);
		return exchange.getResponse().setComplete();
	}
}

test
correct
FALSE

5. Filter execution sequence

Each filter must specify an order value. The smaller the order value, the higher the priority and the higher the execution order
.
GlobalFilter specifies the order value by implementing the @ order annotation, which we specify ourselves
.
The order of routing filter and defaultFilter is specified by Spring. By default, it is incremented from 1 in the order of declaration (that is, yml configuration. The higher the above, the higher)
.
When the order value of the filter is the same, it will be executed in the order of defaultfilter > routing filter > globalfilter.

6. Cross domain problem handling

Cross domain: domain name inconsistency is cross domain, mainly including
1. Different domain names: www.taobao.com COM and www.taobao.com Org and www.jd.com com
2. The domain name is the same, but the ports are different: 8080 and 8081
Cross domain problem: the browser prohibits cross domain ajax requests between the initiator of the request and the server, and the request is intercepted by the browser
Solution: CORS

 #Gateway configuration
    gateway:
      globalcors: # Global cross domain processing
        add-to-simple-url-handler-mapping: true # Solve the problem that the options request is intercepted
        corsConfiguration:
          '[/**]':
            allowedOrigins: # Which networks are allowed for cross domain requests
              - "http://localhost:8881"
              - "http:www.leyou.com"
            allowedMethods: # Allowed cross domain ajax request mode
              - "GET"
              - "POST"
              - "DELETE"
              - "PUT"
              - "OPTIONS"
            allowedHeaders: "*"  #Header information allowed to be carried in the request
            allowCredentials: true  # Allow cookie s
            maxAge: 360000 # Validity of this cross domain detection

8. Configure all codes

server:
  port: 88
spring:
  application:
    name: mall-gateway
  cloud:
    nacos:
      config:
        server-addr: 127.0.0.1:8848
    #Gateway configuration
    gateway:
      globalcors: # Global cross domain processing
        add-to-simple-url-handler-mapping: true # Solve the problem that the options request is intercepted
        corsConfiguration:
          '[/**]':
            allowedOrigins: # Which networks are allowed for cross domain requests
              - "http://localhost:8881"
              - "http:www.leyou.com"
            allowedMethods: # Allowed cross domain ajax request mode
              - "GET"
              - "POST"
              - "DELETE"
              - "PUT"
              - "OPTIONS"
            allowedHeaders: "*"  #Header information allowed to be carried in the request
            allowCredentials: true  # Allow cookie s
            maxAge: 360000 # Validity of this cross domain detection
      routes:
        - id: coupon
          uri: http://127.0.0.1:8881 / # request address to go
         # uri: lb://The destination address lb of the coupon # route is load balancing, followed by the service name
          predicates:  # Routing assertion is to judge whether the request meets the conditions of routing rules
            #- Query=url,coupon      # If the URL has / coupon, go to the uri address above. For example: url=coupon
            - Path=/coupon/**      # This url is matched according to the path. It meets the requirements as long as it starts with / coupon
            #- After=2037-01-20T17:42:47.789-07:00[Asia/Shanghai]  # You can access it after this time
          #filters: #filter
            #- AddRequestHeader=Truth,niubi!  #Add request header

        - id: member
          uri: http://127.0.0.1:8882 / # request address to go
          # uri: lb://The target address lb of the member # route is load balancing, followed by the service name
          predicates: # Routing assertion is to judge whether the request meets the conditions of routing rules
            #- Query=url,member    # If the URL has / coupon, go to the upper uri address url=member
            - Path=/member/**      # This url is matched according to the path. It meets the requirements as long as it starts with / member

      default-filters: #The default filter will take effect for all routing requests
        - AddRequestHeader=Truth,niubi!

To be added......