学习Spring Cloud中eureka注册中心添加security认证，eureka client注册启动报错

最近使用SpringCloud在eureka server端添加security登录认证之后，eureka client注册启动一直报错，大概意思是未发现eureka server，导致注册启动失败！

2018-08-09 14:50:06.042  WARN 13256 --- [nfoReplicator-0] c.n.discovery.InstanceInfoReplicator     : There was a problem with the instance info replicator

com.netflix.discovery.shared.transport.TransportException: Cannot execute request on any known server

解决办法分两个版本用不同的方式：

• 首先老版本(Spring Cloud 2.0以下)：

1. 1在application.yml配置中添加如下配置：

security:
  basic:
    enabled: true # 开启基于HTTP basic的认证
  user:
    name: user  # 配置登录的账号是user
    password: password123 #配置登录的密码是password123

1. 2并在pom.xml中添加如下依赖：

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-security</artifactId>
</dependency>

• 新版本(Spring Cloud2.0以上)：

1. 1 在application.yml添加如下配置：

spring:
  application:
    name: eureka-server
  security:
    user:
      name: user
      password: password123

1. 2 在pom.xml中添加如下依赖：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-security</artifactId>
</dependency>

1. 3 在eureka server启动类继承WebSecurityConfigurerAdapter并重写configure方法从而打开basic这个配置，新版的spring Cloud中basic.enabled是禁用的。

security:
  basic:
    enabled: true (enabled出现红波浪线禁用状态，即失效了)
  user:
    name: user
    password: password123

通过如下代码即可解决：

@SpringBootApplication
@EnableEurekaServer
public class EurekaApplication extends WebSecurityConfigurerAdapter {
    public static void main(String[] args) {
        SpringApplication.run(EurekaApplication.class, args);
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        // Configure HttpSecurity as needed (e.g. enable http basic).
        http.sessionManagement().sessionCreationPolicy(SessionCreationPolicy.NEVER);
        http.csrf().disable();
        //注意：为了可以使用 http://${user}:${password}@${host}:${port}/eureka/ 这种方式登录,所以必须是httpBasic,
        // 如果是form方式,不能使用url格式登录
        http.authorizeRequests().anyRequest().authenticated().and().httpBasic();

    }
}