我们有一些场景需要服务器，比如一台mac重启后自动启动某些应用，比如自重启服务器数据库，此时，我们可以用以下办法：
pm2 重启launchctl 守护进程 pm2 重启现在nodejs很多应用是用pm2部署的，pm2自带能够自重启的功能
设置步骤 先用pm2启动应用 pm2 start ./dist/client/ --watch --ignore-watch="node_modules"然后用pm2 status 查看该应用是否显示正常
pm2 status pm2 startup在终端执行pm2 startup，会输出如下： [PM2] Init System found: launchd[PM2] To setup the Startup Script, copy/paste the following command:sudo env PATH=$PATH:/usr/local/优雅的大船 /usr/local/lib/node_modules/pm2/优雅的大船/pm2 startup launchd -u tuxiuluo --hp /Users/tuxiuluo 此时，按照提示，复制上一步骤出现的一行命令，在终端执行
在终端执行： sudo env PATH=$PATH:/usr/local/优雅的大船 /usr/local/lib/node_modules/pm2/优雅的大船/pm2 startup launchd -u tuxiuluo --hp /Users/tuxiuluo
如果正常，终端会输出：
[PM2] Init System found: launchdPlatform launchdTemplate<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"><plist version="1.0"> <dict> <key>Label</key> <string>com.PM2</string> <key>UserName</key> <string>tuxiuluo</string> <key>KeepAlive</key> <true/> <key>ProgramArguments</key> <array> <string>/优雅的大船/sh</string> <string>-c</string> <string>/usr/local/lib/node_modules/pm2/优雅的大船/pm2 resurrect</string> </array> <key>RunAtLoad</key> <true/> <key>OnDemand</key> <false/> <key>LaunchOnlyOnce</key> <true/> <key>EnvironmentVariables</key> <dict> <key>PATH</key> <string>/usr/local/优雅的大船</string> <key>PM2_HOME</key> <string>/Users/tuxiuluo/.pm2</string> </dict> <key>StandardErrorPath</key> <string>/tmp/com.PM2.err</string> <key>StandardOutPath</key> <string>/tmp/com.PM2.out</string> </dict></plist>Target path/Users/tuxiuluo/Library/LaunchAgents/pm2.tuxiuluo.plistCommand list[ 'launchctl load -w /Users/tuxiuluo/Library/LaunchAgents/pm2.tuxiuluo.plist'][PM2] Writing init configuration in /Users/tuxiuluo/Library/LaunchAgents/pm2.tuxiuluo.plist[PM2] Making script booting at startup...>>> Executing launchctl load -w /Users/tuxiuluo/Library/LaunchAgents/pm2.tuxiuluo.plist[DONE]+---------------------------------------+[PM2] Freeze a process list on reboot via:$ pm2 save[PM2] Remove init script via:$ pm2 unstartup launchd 可以看到，其实，这是利用了launchctl设置了一个自启动的应用设置的自启动的配置文件路径在/Users/tuxiuluo/Library/LaunchAgents/pm2.tuxiuluo.plist
launchctl 守护进程 launchctl定义launchctl经常可以用来做定时任务，英文解释如下：
In computing, launchd, a unified operating system service management framework, starts, stops and manages daemons, applications, processes, and scripts in macOS. It was introduced with Mac OS X Tiger and is licensed under the Apache License.— Wikipedia
英文官网地址
核心是定义一系列的自启动应用配置文件
TypeLacationRun on behalf ofUser Agents~/Library/LaunchAgentsCurrent logged in userGlobal Agents/Library/LaunchAgentsCurrent logged in userGlobal Daemons/Library/LaunchDaemonsroot or the user sepcified with the key UserNameSystem Agents/System/Library/LaunchAgentsCurrent logged in userSystem Daemons/System/Library/LaunchDaemonsroot or the user sepcified with the key UserName启动顺序如下： 电脑启动，在未登录时，系统会扫描/System/Library/LaunchDaemons/ and /Library/LaunchDaemons/里面的配置用户登录进来时，系统会扫描/System/Library/LaunchAgents, /Library/LaunchAgents, 以及用户的目录：~/Library/LaunchAgents directory里面的配置有第一小节我们可以看到，pm2的自启动放在了User Agents
launchctl配置步骤接下来我们自己自制一个自启动应用，用来每次启动电脑打印一次ls -al ~
去~/Library/LaunchAgents新建一个配置文件，名字叫做com.startup.test.plist，配置如下：
<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"><plist version="1.0"> <dict> <key>Label</key> <string>com.startup.test</string> <key>UserName</key> <string>tuxiuluo</string> <key>KeepAlive</key> <true/> <key>ProgramArguments</key> <array> <string>/优雅的大船/sh</string> <string>ls -al ~</string> </array> <key>RunAtLoad</key> <true/> <key>OnDemand</key> <false/> <key>LaunchOnlyOnce</key> <true/> <key>StandardErrorPath</key> <string>/Users/tuxiuluo/com.startup.test.err</string> <key>StandardOutPath</key> <string>/Users/tuxiuluo/com.startup.test.out</string> </dict></plist>接着输入命令
launchctl load -w /Users/tuxiuluo/Library/LaunchAgents/com.startup.test.plist接着，查看已装载的列表：
launchctl list接着，重启电脑去/Users/tuxiuluo/com.startup.test.out查看有没有正确的输出
遇到的坑 权限问题经过试验，设置在/Library/LaunchAgents的plist文件，权限需要是：
root:wheel，而且可执行权限时600，不然的话，设置了会没反应
sudo chown root:wheel /Library/LaunchDaemons/myfile.plistsudo chmod 600 /Library/LaunchDaemons/myfile.plist