Spring boot admin 日志_springboot admin 日志

前言

以前写过Spring Boot Admin的使用教程，还配置了各种路径参数。最近有留言说client的log怎么查看，其实log这个没写是因为，不能满足性能与管理的需要，ELK技术很成熟，搜索也是，备份管理都有现成的，但是估计有些小公司不需要这样的技术，只需要可以快速查看的日志入口就可以了。下面来试试。

1. SBA log示例

此次使用consul + admin + client

1. 1 consul启动

由于我的电脑是macos，只需要./consul agent -dev即可，win更容易，直接双击启动

1.2 admin server

pom依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>spring-boot-admin</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
 
    <artifactId>admin-derver</artifactId>
 
    <dependencies>
        <dependency>
            <groupId>de.codecentric</groupId>
            <artifactId>spring-boot-admin-starter-server</artifactId>
            <version>2.3.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.3.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
            <version>2.3.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-consul-discovery</artifactId>
            <version>2.2.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.30</version>
        </dependency>
    </dependencies>
</project>

bootMain类

package com.feng.admin.server;
 
import de.codecentric.boot.admin.server.config.EnableAdminServer;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
 
@SpringBootApplication
@EnableAdminServer
@EnableDiscoveryClient
public class ServerMain {
    public static void main(String[] args) {
        SpringApplication.run(ServerMain.class, args);
    }
}

application

server.port=8082
spring.application.name=AdminServer
 
 
management.endpoint.health.show-details=always
management.endpoints.web.exposure.include=*
 
spring.cloud.consul.host=localhost
spring.cloud.consul.port=8500
spring.cloud.consul.discovery.service-name=${spring.application.name}

1.3 admin client

client同理，复制AdminServer，即可去除<artifactId>spring-boot-admin-starter-server</artifactId>依赖即可，去除AdminServer注解，修改端口

查看结果 

2. client log改造

所谓的log实时查看是client提供一个读取本地文件的接口，然后admin定时调用显示，达到实时展示的效果。需要2步即可

2.1 application增加

management.endpoint.logfile.external-file=/Users/huahua/logs/boot.log

还有其他方式，后面说

2.2 增加logback-spring.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <property name="APP_Name" value="logback" />
    　　　<contextName>${APP_Name}</contextName>
    <!--定义日志文件的存储地址 勿在 LogBack 的配置中使用相对路径，请根据需求配置路径-->
    <property name="LOG_HOME" value="/Users/huahua/logs/" />
 
    <!-- 彩色日志依赖的渲染类 -->
    <conversionRule conversionWord="clr" converterClass="org.springframework.boot.logging.logback.ColorConverter" />
    <conversionRule conversionWord="wex" converterClass="org.springframework.boot.logging.logback.WhitespaceThrowableProxyConverter" />
    <conversionRule conversionWord="wEx" converterClass="org.springframework.boot.logging.logback.ExtendedWhitespaceThrowableProxyConverter" />
    <!-- 彩色日志格式 -->
    <property name="CONSOLE_LOG_PATTERN"
              value="${CONSOLE_LOG_PATTERN:-%clr(%d{yyyy-MM-dd HH:mm:ss.SSS}){faint} %clr(${LOG_LEVEL_PATTERN:-%5p}) %clr(${PID:- }){magenta} %clr(---){faint} %clr([%15.15t]){faint} %clr(%-40.40logger{39}){cyan} %clr(LN:%L){faint} %m%n${LOG_EXCEPTION_CONVERSION_WORD:-%wEx}}" />
 
    <!-- 控制台输出 -->
    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
            <pattern>${CONSOLE_LOG_PATTERN}</pattern>
            <charset>utf8</charset>
        </encoder>
    </appender>
 
    <!-- 按照每天生成日志文件 -->
    <appender name="FILE"  class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${LOG_HOME}/boot.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <!--日志文件输出的文件名-->
            <FileNamePattern>${LOG_HOME}/boot-%d{yyyy-MM-dd}.log</FileNamePattern>
            <!--日志文件保留天数-->
            <MaxHistory>3</MaxHistory>
        </rollingPolicy>
        <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
            <!--格式化输出：%d表示日期，%thread表示线程名，%-5level：级别从左显示5个字符宽度%msg：日志消息，%n是换行符-->
            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50}:%L - %msg%n</pattern>
        </encoder>
    </appender>
 
    <logger name="org.springframework.boot.actuate.endpoint.web.servlet" level="trace"/>
 
    <!-- 日志输出级别  ，注意：如果不写<appender-ref ref="FILE" /> ，将导致springbootadmin找不到文件，无法查看日志 -->
    <root level="INFO">
        <appender-ref ref="STDOUT" />
        <appender-ref ref="FILE" />
    </root>
</configuration>

注意这个，必须为trace，可以打印actuator的HTTP requestmapping信息

<logger name="org.springframework.boot.actuate.endpoint.web.servlet" level="trace"/>

重点关注logfile接口，这个接口必须配置参数才能出现

2.3 效果如下

F12可以看到，页面在定时请求

3. 原理分析

根源在一个自动配置上

public class LogFile {
    public static final String FILE_NAME_PROPERTY = "logging.file.name";
    public static final String FILE_PATH_PROPERTY = "logging.file.path";
 
 
 
package org.springframework.boot.actuate.autoconfigure.logging;
 
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.boot.actuate.autoconfigure.endpoint.condition.ConditionalOnAvailableEndpoint;
import org.springframework.boot.actuate.logging.LogFileWebEndpoint;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.condition.ConditionMessage;
import org.springframework.boot.autoconfigure.condition.ConditionOutcome;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.autoconfigure.condition.SpringBootCondition;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.boot.logging.LogFile;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ConditionContext;
import org.springframework.context.annotation.Conditional;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;
import org.springframework.core.type.AnnotatedTypeMetadata;
import org.springframework.util.StringUtils;
 
/**
 * {@link EnableAutoConfiguration Auto-configuration} for {@link LogFileWebEndpoint}.
 *
 * @author Andy Wilkinson
 * @author Christian Carriere-Tisseur
 * @since 2.0.0
 */
@Configuration(proxyBeanMethods = false)
@ConditionalOnAvailableEndpoint(endpoint = LogFileWebEndpoint.class)
@EnableConfigurationProperties(LogFileWebEndpointProperties.class)
public class LogFileWebEndpointAutoConfiguration {
 
	@Bean
	@ConditionalOnMissingBean
    //条件式，很关键，默认条件是false
	@Conditional(LogFileCondition.class)
	public LogFileWebEndpoint logFileWebEndpoint(ObjectProvider<LogFile> logFile,
			LogFileWebEndpointProperties properties) {
		return new LogFileWebEndpoint(logFile.getIfAvailable(), properties.getExternalFile());
	}
 
	private static class LogFileCondition extends SpringBootCondition {
 
		@Override
        //条件判定
		public ConditionOutcome getMatchOutcome(ConditionContext context, AnnotatedTypeMetadata metadata) {
			Environment environment = context.getEnvironment();
			String config = getLogFileConfig(environment, LogFile.FILE_NAME_PROPERTY);
			ConditionMessage.Builder message = ConditionMessage.forCondition("Log File");
			if (StringUtils.hasText(config)) {
				return ConditionOutcome.match(message.found(LogFile.FILE_NAME_PROPERTY).items(config));
			}
			config = getLogFileConfig(environment, LogFile.FILE_PATH_PROPERTY);
			if (StringUtils.hasText(config)) {
				return ConditionOutcome.match(message.found(LogFile.FILE_PATH_PROPERTY).items(config));
			}
			config = environment.getProperty("management.endpoint.logfile.external-file");
			if (StringUtils.hasText(config)) {
				return ConditionOutcome.match(message.found("management.endpoint.logfile.external-file").items(config));
			}
			return ConditionOutcome.noMatch(message.didNotFind("logging file").atAll());
		}
 
		private String getLogFileConfig(Environment environment, String configName) {
			return environment.resolvePlaceholders("${" + configName + ":}");
		}
 
	}
 
}

所以logging.file.name、logging.file.path、management.endpoint.logfile.external-file都可以开启条件

logging.file.path配置要注意，这个是个坑，会默认spring.log的文件，logging.file.name不会

public String toString() {
        return StringUtils.hasLength(this.file) ? this.file : (new File(this.path, "spring.log")).getPath();
    }

另外可以看到LogFileWebEndpointProperties这个配置

所以management.endpoint.logfile.externalFile也是可以的，实际上

Spring在解析properties时会在Spring缓存的Map中，把management.endpoint.logfile.external-file的key会转换成management.endpoint.logfile.externalFile。

 

最终的结果是实例化LogFileWebEndpoint，创建endpoint的requestmapping接口映射

/*
 * Copyright 2012-2019 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
package org.springframework.boot.actuate.logging;
 
import java.io.File;
 
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
 
import org.springframework.boot.actuate.endpoint.annotation.Endpoint;
import org.springframework.boot.actuate.endpoint.annotation.ReadOperation;
import org.springframework.boot.actuate.endpoint.web.annotation.WebEndpoint;
import org.springframework.boot.logging.LogFile;
import org.springframework.core.io.FileSystemResource;
import org.springframework.core.io.Resource;
 
/**
 * Web {@link Endpoint @Endpoint} that provides access to an application's log file.
 *
 * @author Johannes Edmeier
 * @author Phillip Webb
 * @author Andy Wilkinson
 * @since 2.0.0
 */
@WebEndpoint(id = "logfile")
public class LogFileWebEndpoint {
 
	private static final Log logger = LogFactory.getLog(LogFileWebEndpoint.class);
 
	private File externalFile;
 
	private final LogFile logFile;
 
	public LogFileWebEndpoint(LogFile logFile, File externalFile) {
		this.externalFile = externalFile;
		this.logFile = logFile;
	}
 
	@ReadOperation(produces = "text/plain; charset=UTF-8")
    //最终是requestmapping，访问这个方法，本质是读取文件
	public Resource logFile() {
		Resource logFileResource = getLogFileResource();
		if (logFileResource == null || !logFileResource.isReadable()) {
			return null;
		}
		return logFileResource;
	}
 
	private Resource getLogFileResource() {
		if (this.externalFile != null) {
			return new FileSystemResource(this.externalFile);
		}
		if (this.logFile == null) {
			logger.debug("Missing 'logging.file.name' or 'logging.file.path' properties");
			return null;
		}
		return new FileSystemResource(this.logFile.toString());
	}
 
}

 

总结

其实Spring Boot Admin显示client的日志原理很简单，client暴露HTTP，admin定时调用。client端取日志需要配置才能开启，是读取本地文件。

源码分析也验证了上面的观点。