CentOS 7自定义系统服务（以Phoebus-Olog为例）

需要开启的服务：

MongoDB
ElasticSearch
Phoebus-Olog后端服务
Phoebus-Olog-web-client前端服务

配置系统服务的方式：
systemd

把spring-boot项目配置为Linux systemd服务
SpringBoot2.X 实战12-安装为systemd服务部署
正确、安全地停止SpringBoot应用服务
优雅的启动、停止、重启你的SpringBoot项目
spring boot 打成 jar 包采用 systemctl 设置自启动
springboot启动脚本start.sh和停止脚本 stop.sh

1. 创建服务启停脚本

创建脚本 /home/dongxw/modules/olog/phoebus-olog-master/phoebus-olog-service.sh，用于启停相应服务：

### This script is used to start/stop Phoebus-Olog service.MONGODB_HOME=/home/dongxw/mongodb-linux-x86_64-rhel70-5.0.6ES_HOME=/home/dongxw/elasticsearch-6.8.4
ES_PORT=9200
ES_USER=dongxwBACKEND_PORT=8080
BACKEND_DIR=/home/dongxw/modules/olog/phoebus-olog-master
JAVA_HOME=/home/dongxw/jdk-16.0.2
JAR_PACK=service-olog-2.0.5-SNAPSHOT.jar
BACKEND_LOG_DIR=$BACKEND_DIR/logsFRONTEND_PORT=3000
FRONTEND_DIR=/home/dongxw/modules/olog/phoebus-olog-web-client-1.0.6## Start MongoDB.
function start_mongodb
{cd $MONGODB_HOME./bin/mongod --dbpath db --logpath log/mongod.log -fork
}## Stop MongoDB.
function stop_mongodb
{pid=`ps -ef | grep mongod | grep -v grep | awk '{print $2}'`kill  $pid
}## Start ElasticSearch.
function start_elasticsearch
{### Cannot run elasticsearch as rootsu $ES_USER -c "$ES_HOME/bin/elasticsearch -d"
}## Stop ElasticSearch.
function stop_elasticsearch
{pid=`sudo netstat -nltp | grep -m 1 $ES_PORT | awk '{print $7}' | awk 'BEGIN {FS="/"} {print $1}'`kill  $pid
}## Start backend service.
function start_phoebus_olog_service
{cd $BACKEND_DIR/target$JAVA_HOME/bin/java -jar $JAR_PACK > $BACKEND_LOG_DIR/phoebus-olog-service_`date "+%F"`.log  &
}## Stop backend service.
function stop_phoebus_olog_service
{pid=`sudo netstat -nltp | grep $BACKEND_PORT | awk '{print $7}' | awk 'BEGIN {FS="/"} {print $1}'`kill  $pid
}## Start frontend service.
function start_phoebus_olog_web_client
{deploy_dir=$FRONTEND_DIR/buildbusybox httpd -vv -p $FRONTEND_PORT -h $deploy_dir
}## Stop frontend service.
function stop_phoebus_olog_web_client
{pid=`sudo netstat -nltp | grep $FRONTEND_PORT | awk '{print $7}' | awk 'BEGIN {FS="/"} {print $1}'`kill  $pid
}case "$1" instart)start_mongodbstart_elasticsearchstart_phoebus_olog_servicestart_phoebus_olog_web_client;;stop)stop_phoebus_olog_servicestop_phoebus_olog_web_clientstop_mongodbstop_elasticsearch;;
esac

2. 创建systemd服务脚本

创建脚本 /etc/systemd/system/phoebus-olog.service，用于systemd管理：

[Unit]
Description=Phoebus Olog service
After=network.target
Requires=[Service]
ExecStart=/bin/bash -c "/home/dongxw/modules/olog/phoebus-olog-master/phoebus-olog-service.sh start"
ExecStop=/bin/bash -c "/home/dongxw/modules/olog/phoebus-olog-master/phoebus-olog-service.sh stop"
SuccessExitStatus=143
Type=forking[Install]
WantedBy=multi-user.target

3. 启动服务

$ sudo systemctl daemon-reload
$ sudo systemctl start phoebus-olog.service
$ sudo systemctl enable phoebus-olog.service

4. 遇到问题

4.1 ExecStart/ExecStop 不支持复杂bash语法

ExecStart/ExecStop仅支持【指令参数参数 …】的形式，不接受 <、>、>>、|、&等字符，很多bash语法也不接受。
当在phoebus-olog.service脚本中的ExecStart= 和 ExecStop= 使用复杂bash语法时，无法通过systemd的语法校验：

$ sudo systemctl daemon-reload
$ sudo systemctl status -l phoebus-olog.service
· phoebus-olog.service - Phoebus Olog serviceLoaded: error (Reason: Invalid argument)Active: inactive (dead)Dec 23 19:00:07 localhost.localdomain systemd[1]: [/etc/systemd/system/phoebus-olog.service:7] Trailing garbage, ignoring.
Dec 23 19:00:07 localhost.localdomain systemd[1]: [/etc/systemd/system/phoebus-olog.service:8] Trailing garbage, ignoring.
Dec 23 19:00:07 localhost.localdomain systemd[1]: phoebus-olog.service lacks both ExecStart= and ExecStop= setting. Refusing.

systemd: Service lacks both ExecStart= and ExecStop= setting. Refusing

4.2 Java版本导致的systemd启动失败

由于systemd服务以root身份启动，所以自动读取root用户的环境变量。phoebus-olog-service.sh中未指定运行jar包的Java版本时，会优先使用环境变量中搜索到的靠前的Java版本运行，报错如下：

$ sudo systemctl status -l phoebus-olog.service
鈼?phoebus-olog.service - Phoebus Olog serviceLoaded: loaded (/etc/systemd/system/phoebus-olog.service; enabled; vendor preset: disabled)Active: failed (Result: exit-code) since Sun 2022-12-25 21:23:57 CST; 3s agoProcess: 28883 ExecStart=/bin/bash -c /home/dongxw/modules/olog/phoebus-olog-master/phoebus-olog-service.sh start (code=exited, status=0/SUCCESS)Main PID: 28885 (code=exited, status=1/FAILURE)Dec 25 21:23:57 localhost.localdomain bash[28883]: at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
Dec 25 21:23:57 localhost.localdomain bash[28883]: at java.lang.Class.forName0(Native Method)
Dec 25 21:23:57 localhost.localdomain bash[28883]: at java.lang.Class.forName(Class.java:348)
Dec 25 21:23:57 localhost.localdomain bash[28883]: at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:46)
Dec 25 21:23:57 localhost.localdomain bash[28883]: at org.springframework.boot.loader.Launcher.launch(Launcher.java:107)
Dec 25 21:23:57 localhost.localdomain bash[28883]: at org.springframework.boot.loader.Launcher.launch(Launcher.java:58)
Dec 25 21:23:57 localhost.localdomain bash[28883]: at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:88)
Dec 25 21:23:57 localhost.localdomain systemd[1]: phoebus-olog.service: main process exited, code=exited, status=1/FAILURE
Dec 25 21:23:57 localhost.localdomain systemd[1]: Unit phoebus-olog.service entered failed state.
Dec 25 21:23:57 localhost.localdomain systemd[1]: phoebus-olog.service failed.

发现是Java版本原因。当前jar包以jdk-16.0.2编译，然而通过openjdk 1.8.0_262运行，就会报该错误：

$ whereis java
java: /usr/bin/java /usr/lib/java /etc/java /usr/share/java /home/dongxw/jdk-16.0.2/bin/java /usr/share/man/man1/java.1.gz$ /usr/bin/java -version
openjdk version "1.8.0_262"
OpenJDK Runtime Environment (build 1.8.0_262-b10)
OpenJDK 64-Bit Server VM (build 25.262-b10, mixed mode)$ /usr/bin/java -jar ./target/service-olog-2.0.5-SNAPSHOT.jar
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/phoebus/olog/Application has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0at java.lang.ClassLoader.defineClass1(Native Method)at java.lang.ClassLoader.defineClass(ClassLoader.java:756)at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)at java.net.URLClassLoader.defineClass(URLClassLoader.java:468)at java.net.URLClassLoader.access$100(URLClassLoader.java:74)at java.net.URLClassLoader$1.run(URLClassLoader.java:369)at java.net.URLClassLoader$1.run(URLClassLoader.java:363)at java.security.AccessController.doPrivileged(Native Method)at java.net.URLClassLoader.findClass(URLClassLoader.java:362)at java.lang.ClassLoader.loadClass(ClassLoader.java:418)at org.springframework.boot.loader.LaunchedURLClassLoader.loadClass(LaunchedURLClassLoader.java:151)at java.lang.ClassLoader.loadClass(ClassLoader.java:351)at java.lang.Class.forName0(Native Method)at java.lang.Class.forName(Class.java:348)at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:46)at org.springframework.boot.loader.Launcher.launch(Launcher.java:107)at org.springframework.boot.loader.Launcher.launch(Launcher.java:58)at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:88)

4.3 kill -9 导致的systemd退出状态异常（failed）

kill -9导致返回状态status=9/KILL，systemd显示关闭失败（failed）：

$ sudo systemctl stop phoebus-olog.service
$ sudo systemctl status -l phoebus-olog.service
鈼?phoebus-olog.service - Phoebus Olog serviceLoaded: loaded (/etc/systemd/system/phoebus-olog.service; enabled; vendor preset: disabled)Active: failed (Result: signal) since Sun 2022-12-25 21:36:04 CST; 2s agoProcess: 30079 ExecStop=/bin/bash -c /home/dongxw/modules/olog/phoebus-olog-master/phoebus-olog-service.sh stop (code=exited, status=0/SUCCESS)Process: 29927 ExecStart=/bin/bash -c /home/dongxw/modules/olog/phoebus-olog-master/phoebus-olog-service.sh start (code=exited, status=0/SUCCESS)Main PID: 29929 (code=killed, signal=KILL)Dec 25 21:35:23 localhost.localdomain bash[29927]: Dec 25, 2022 9:35:23 PM org.phoebus.olog.Application configureTruststore
Dec 25 21:35:23 localhost.localdomain bash[29927]: INFO: using default javax.net.ssl.trustStore
Dec 25 21:35:23 localhost.localdomain bash[29927]: Dec 25, 2022 9:35:23 PM org.phoebus.olog.Application configureTruststore
Dec 25 21:35:23 localhost.localdomain bash[29927]: INFO: using default javax.net.ssl.trustStorePassword
Dec 25 21:36:04 localhost.localdomain systemd[1]: Stopping Phoebus Olog service...
Dec 25 21:36:04 localhost.localdomain sudo[30093]:     root : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/usr/bin/netstat -nltp
Dec 25 21:36:04 localhost.localdomain systemd[1]: phoebus-olog.service: main process exited, code=killed, status=9/KILL
Dec 25 21:36:04 localhost.localdomain systemd[1]: Stopped Phoebus Olog service.
Dec 25 21:36:04 localhost.localdomain systemd[1]: Unit phoebus-olog.service entered failed state.
Dec 25 21:36:04 localhost.localdomain systemd[1]: phoebus-olog.service failed.

kill -9 和 kill -15到底有什么区别呢？该如何选择呢？

4.4 spring-boot:stop失败

Default fork value for spring-boot:stop is not consistent
Spring Boot Maven Plugin

4.5 can not run elasticsearch as root

ElasticSearch不允许使用root用户启动，而systemd以root用户身份运行，因此会报错：

$ vi /home/dongxw/elasticsearch-6.8.4/logs/elasticsearch.log
...
[2022-12-26T16:53:18,615][ERROR][o.e.b.Bootstrap          ] [unknown] Exception
java.lang.RuntimeException: can not run elasticsearch as rootat org.elasticsearch.bootstrap.Bootstrap.initializeNatives(Bootstrap.java:103) ~[elasticsearch-6.8.4.jar:6.8.4]at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:170) ~[elasticsearch-6.8.4.jar:6.8.4]at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:333) [elasticsearch-6.8.4.jar:6.8.4]at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:159) [elasticsearch-6.8.4.jar:6.8.4]at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:150) [elasticsearch-6.8.4.jar:6.8.4]at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) [elasticsearch-6.8.4.jar:6.8.4]at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:124) [elasticsearch-cli-6.8.4.jar:6.8.4]at org.elasticsearch.cli.Command.main(Command.java:90) [elasticsearch-cli-6.8.4.jar:6.8.4]at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:116) [elasticsearch-6.8.4.jar:6.8.4]at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:93) [elasticsearch-6.8.4.jar:6.8.4]
[2022-12-26T16:53:18,622][WARN ][o.e.b.ElasticsearchUncaughtExceptionHandler] [unknown] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: java.lang.RuntimeException: can not run elasticsearch as rootat org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:163) ~[elasticsearch-6.8.4.jar:6.8.4]at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:150) ~[elasticsearch-6.8.4.jar:6.8.4]at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) ~[elasticsearch-6.8.4.jar:6.8.4]at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:124) ~[elasticsearch-cli-6.8.4.jar:6.8.4]at org.elasticsearch.cli.Command.main(Command.java:90) ~[elasticsearch-cli-6.8.4.jar:6.8.4]at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:116) ~[elasticsearch-6.8.4.jar:6.8.4]at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:93) ~[elasticsearch-6.8.4.jar:6.8.4]
Caused by: java.lang.RuntimeException: can not run elasticsearch as rootat org.elasticsearch.bootstrap.Bootstrap.initializeNatives(Bootstrap.java:103) ~[elasticsearch-6.8.4.jar:6.8.4]at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:170) ~[elasticsearch-6.8.4.jar:6.8.4]at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:333) ~[elasticsearch-6.8.4.jar:6.8.4]at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:159) ~[elasticsearch-6.8.4.jar:6.8.4]... 6 more

ES5之后，加"-Des.insecure.allow.root=true"参数已经不再行得通：
ELASTICSEARCH ROOT身份运行
因此需要在启动ES时，su到非root用户身份。

shell脚本里切换用户执行命令
shell 脚本之切换用户

4.6 su用户无法识别命令参数

报错：

bash: /home/dongxw/elasticsearch-6.8.4/bin/elasticsearch -d: No such file or directory

这是因为su用户的语句中忘了加“-c"，因此后边想通过su用户执行的语句被当成了单独的一条命令：

su $ES_USER "$ES_HOME/bin/elasticsearch -d"

这里"$ES_HOME/bin/elasticsearch -d"被当成了单独的命令。