Bash:通过ssh启动远程python应用程序并获取其PID [英] Bash: start remote python application through ssh and get its PID

问题描述

我正在创建一个bash脚本，将新文件从Windows机器复制到远程linux centos服务器(我使用git-shell运行此脚本)，然后我想重新启动服务器上运行的python应用程序，使用这些新文件.

I'm creating a little bash script to copy new files from a windows machine to a remote linux centos server (i run this script using the git-shell) then i want to restart the python application thats running in the server to use those new files.

问题在于，每次我运行此脚本时，我都想在再次启动之前结束实际的运行过程，因此我想获取启动过程的pid并将其保存到远程主机中的文件中，因此我可以从那里下一次我运行该程序读它并杀死它.

The problem is that everytime i run this script i want to end the actual running process before i start it again, so i want to get the pid of the process i start and save it to a file in the remote host so i can read it from there the next time i run the program and kill it.

到目前为止，我的代码与此类似:

My code by now looks similar to this:

echo "Copying code files to server..."
# The destination folder has to exist in the server
scp -r ./python/ root@myserver:/root/

echo "Checking for running processes..."

if ssh root@myserver 'ls dmr.pid >/dev/null'; then
    echo "PID file exists, reading file..."
    PID=$(ssh root@myserver 'cat dmr.pid')

    # Terminate the actual process
    echo "Terminating the process with PID '$PID'..."
    ssh root@myserver 'kill $PID'
else
    echo "PID file doesn't exist, not known processes running"
fi

# Restart the server and get the PID
echo "Restarting the server..."
ssh root@myserver 'python /root/python/run_dev_server.py > /dev/null 2>&1 &'

SERV_PID=$(ssh root@myserver 'echo $!')

echo "Saving PID to file dmr.pid"
ssh root@myserver "echo '$SERV_PID' > \"dmr.pid\""

echo "Sucesfully finished!"

重要的几行是:

ssh root@myserver 'python /root/python/run_dev_server.py > /dev/null 2>&1 &'
SERV_PID=$(ssh root@myserver 'echo $!')

这个问题是脚本完成了，但是文件和$ SERV_PID变量一样都是空的.

the problem with this is that the script finishes but the file ends up empty as well as the $SERV_PID variable.

如果我不重定向输出，只是做这样的事情:

And if i dont redirect the outputs and just do something like this:

SERV_PID=$(ssh root@myserver 'python /root/python/run_dev_server.py & echo $!')

在重新启动服务器"之后，我陷入了困境，从不获取PID或包含该PID的文件，甚至脚本的末尾.

i get stuck after "Restarting the server" and never get the PID or the file that will contain it or even the end of the script.

但是，如果我在控制台中运行此命令:

But if i run this right in the console:

ssh root@myserver 'python /root/python/run_dev_server.py & echo $!'

我在终端上打印了一个PID.

i get a PID printed to the terminal.

任何对此的建议，将不胜感激.

Any advice on this would be really appreciated.

推荐答案

感谢Kingslndian，我通过执行一个执行我所需的三个步骤的命令来解决了该问题，从而避免了在不同的shell中运行的问题:

Thanks to Kingslndian i solved it by making one single command that did the three steps i required, so with that avoided the problem of running in different shells:

 ssh root@myserver 'python /root/python/run_dev_server.py > /dev/null 2>&1 & echo $! > "dmr.pid"'

这篇关于Bash:通过ssh启动远程python应用程序并获取其PID的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！