Spring Boot调用 Shell 脚本实现看门狗功能

Spring Boot调用 Shell 脚本实现看门狗功能

需要实现看门狗功能，定时检测另外一个程序是否在运行，使用 crontab 仅可以实现检测程序是否正在运行，无法做到扩展，如：手动重启、程序升级(如果只需要实现自动升级功能可以使用 inotify)等功能；最后决定使用 Spring Boot 调用 Shell 脚本来实现

一、脚本

1.1 启动脚本

#!/bin/bash

ps -ef | grep "demo-app-0.0.1-SNAPSHOT.jar" | grep -v "grep"

if [ "$?" -eq 0 ]

then

# sleep

echo $(date "+%Y-%m-%d %H:%M:%S") "process already started!"

else

nohup java -jar -server /project/watchdog/demo-app-0.0.1-SNAPSHOT.jar &

echo $(date "+%Y-%m-%d %H:%M:%S") "process has been started!"

fi

1.2 重启脚本

#!/bin/bash

pid=`ps -ef | grep "demo-app-0.0.1-SNAPSHOT.jar" | grep -v "grep" | awk '{print $2}'`

for id in $pid

do

kill -9 $id

echo "killed $id"

done

nohup java -jar -server /project/watchdog/demo-app-0.0.1-SNAPSHOT.jar &

echo $(date "+%Y-%m-%d %H:%M:%S") "process has been restarted!"

二、功能实现

将脚本放置在程序的资源目录下，每次程序启动时将脚本读取到指定位置，然后再通过定时任务执行脚本

配置内容：

shell:

directory: /project/watchdog

startupFileName: startup.sh

restartFileName: restart.sh

@Configuration

@ConfigurationProperties(prefix = "shell")

public class ShellProperties {

private String directory;

private String startupFileName;

private String restartFileName;

/* getter & setter */

public String getFullName(String fileName) {

return directory + File.separator + fileName;

}

}

2.1 启动时将脚本读取到指定位置

@Component

public class InitRunner implements CommandLineRunner {

@Autowired

private ShellProperties shellProperties;

@Autowired

ResourceLoader resourceLoader;

@Override

public void run(String... args) throws Exception {

generateFile(shellProperties.getStartupFileName());

generateFile(shellProperties.getRestartFileName());

}

private void generateFile(String fileName) throws IOException {

String fileFullName = shellProperties.getFullName(fileName);

File file = new File(fileFullName);

if(file.exists()) {

return;

}

// 如果文件已存在，FileWriter 会先删除再新建

FileWriter fileWriter = new FileWriter(fileFullName);

Resource resource = resourceLoader.getResource("classpath:" + fileName);

InputStream inputStream = resource.http://getInputStream();

InputStreamReader inputStreamReader = new InputStreamReader(inputStream);

BufferedReader bufferedReader = new BufferedReader(inputStreamReader);

String data;

while ((data = bufferedReader.readLine()) != null) {

fileWriter.write(data + "\n");

}

bufferedReader.close();

inputStreamReader.close();

inputStream.close(dVqEDRSjdQ);

fileWriter.close();

// 设置权限，否则会报 Permission denied

file.setReadable(true);

file.setWritable(true);

file.setExecutable(true);

}

}

2.2 定时任务定时任务执行脚本

@Component

public class ShellTask {

private static final Logger logger = LoggerFactory.getLogger(ShellTask.class);

@Autowired

private ShellProperties shellProperties;

@Scheduled(cron = "0/10 * * * * ? ")

public void start() throws IOException {

executeShell(shellProperties.getStartupFileName());

}

private void executeShell(String fileName) throws IOException {

String fileFullName = shellProperties.getFullName(fileName);

File file = new File(fileFullName);

if(!file.exists()) {

logger.error("file {} not existed!", fileFullName);

return;

}

ProcessBuilder processBuilder = new ProcessBuilder(fileFullName);

processBuilder.directory(new Fihttp://le(shellProperties.getDirectory()));

Process process = processBuilder.start();

// String input;

// BufferedReader stdInput = new BufferedReader(new InputStreamReader(process.getInputStream()));

// BufferedReader stdError = new BufferedReader(new InputStreamReader(process.getErrorStream()));

// while ((input = stdInput.readLine()) != null) {

// logger.info(input);

// }

// while ((input = stdError.readLine()) != null)dVqEDRSjdQ {

// logger.error(input);

// }

int runningStatus = 0;

try {

runningStatus = process.waitFor();

} catch (InterruptedException e) {

logger.error("shell", e);

}

if(runningStatus != 0) {

logger.error("failed.");

}else {

logger.info("success.");

}

}

}

2.3 扩展

本例只实现了定时检测程序是否运行，如果没有运行则启动程序；如有需要可以添加接口，调用接口重启程序；或者添加定时任务定时检测程序是否有更新，如果有更新则下载新的 jar 包然后重启程序

看门狗程序自己可以使用 crontab 定时检测是否正在运行，模仿上面的启动脚本编写看门狗的启动脚本，然后添加定时任务：

crontab -e

*/10 * * * * /project/watchdog/watchdog.sh

sudo systemctl reload crond.service

完整代码：github

参考：java去调用并执行shell脚本以及问题总结

总结

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