I am trying to kill a process with pid 38456 using Symfony with this code:
$process1 = new Process('kill -9 38456');
$process1->run();
Pitifully this doesn't work. I think this is due to permissions (Symfony only can kill its own process) but I am not sure about it.
Try to understand which user runs your code:
$process = new Process('whoami');
$process->run();
echo $process->getOutput();
If you are apache or www-data then most probably you have very limited rights.
Your options:
run your script from CLI (command-line) as root. This is the way I recommend
run the process you want to kill from your process
run web-server (apache or php-fpm) as root - very insecure
strange way - web-server can kill process not directly but for example create some file with process id to kill. Also there will be CLI process running by rout that will read this file and kill that process.
Related
I know it sounds weird, but I have a case where Deno would need to shutdown its own host (and kill its own process therefore). Is this possible?
I am specifically needing this for linux (lubuntu), if that's relevant. I guess this requires sudo rights, which sucks but would be an option.
For those interested in details: I'm coding a minecraft server software and if the server has no player for 30 minutes, it will shut itself down to save some power. A raspberry PI that runs 24/7 anyways, has a wake on lan feature, so that it can boot again. After boot, the server manager software would automatically start as a linux service.
You can create a subprocess to do this:
await Deno.run({ cmd: ["shutdown", "-h", "now"] }).status();
Concepts
Deno is capable of spawning a subprocess via Deno.run.
--allow-run permission is required to spawn a subprocess.
Spawned subprocesses do not run in a security sandbox.
Communicate with the subprocess via the stdin, stdout and stderr streams.
Use a specific shell by providing its path/name and its string input switch, e.g. Deno.run({cmd: ["bash", "-c", "ls -la"]});
See also command line - Shutdown from terminal without entering password? - Ask Ubuntu for ideas on how to avoid needing sudo to call shutdown or alternative commands that you can invoke from Deno instead.
To extend on what #mfulton2 wrote, here is how I made it work, so that I did not need to start the program with sudo rights, but still was able to shut down the computer without the use of sudo outside or within the app.
Open or create the following file: sudo nano /etc/sudoer
Add the line username ALL = NOPASSWD: /sbin/shutdown
Add this line %admin ALL = NOPASSWD: /sbin/shutdown
In your deno script, write Deno.run({ cmd: ["shutdown", "-h", "now"]}).status();
Execute script!
Keep in mind that any experienced linux user would potentially tell you that this is very dangerous (it probably is) and that it might not be the very best way. But IMHO, the damage this can cause is minor enough, as it only affects the shutdown command.
I found out that I have quite many Symfony local web server workers registered (around ~35), and the number keeps growing. I usually just start server with symfony serve and then kill it (Ctrl + \) when no longer needed. Apparently killing it leaves a worker behind, as seen in symfony server:status. Running symfony serve again just creates a new worker.
symfony server:status output:
Local Web Server
Not Running
Workers
PID 6327: /usr/bin/php7.2 -S 127.0.0.1:43653 -d variables_order=EGPCS /home/mindaugas/.symfony/php/83247c3521c3ac3990bf3f823ef473db0a9445e1-router.php
PID 24596: /usr/bin/php7.2 -S 127.0.0.1:37789 -d variables_order=EGPCS /home/mindaugas/.symfony/php/83247c3521c3ac3990bf3f823ef473db0a9445e1-router.php
PID 6575: /usr/bin/php7.4 -S 127.0.0.1:42505 -d variables_order=EGPCS /home/mindaugas/.symfony/php/83247c3521c3ac3990bf3f823ef473db0a9445e1-router.php
PID 41550: /usr/bin/php7.4 -S 127.0.0.1:36313 -d variables_order=EGPCS /home/mindaugas/.symfony/php/83247c3521c3ac3990bf3f823ef473db0a9445e1-router.php
...
Environment Variables
None
So my questions regarding this:
#1: is it possible to quickly kill the server? I assume symfony server:stop is more correct way, but that requires additional console window and entering the command.
#2: how to kill those workers that are registered from previous sessions? Trying e.g. kill 6327 says that there's no such process. Also they're not gone after system restart.
Those extra workers are bothering me because for each one of them the server log output in the console is duplicated. So right now on each request to the server I get around 3k lines of log output in the console. Which makes it pretty useless.
I have the same problem after upgrading to Symfony CLI version v4.19.0...
My (very) bad workaround:
rm /home/myusername/.symfony/var/83247c3521c3ac3990bf3f823ef473db0a9445e1/*
Edit: this answer is not accurate, as hinted a by #CrSrr's answer above.
The symfony command adds data to both the ./log and ./var directories. Deleting entries in only one of those does not remove the appearance of non-existent workers in the project directory. I was fooled by checking status in a directory where the server:start had never been run.
A bug report is on file with symfony here.
Just faced with a similar issue. The PIDs were not to be found.
PS G:\workspace\joined> symfony server:status
Local Web Server
Not Running
Workers
PID 7732: C:\php\php-cgi.exe -b 63801 -d error_log=C:\Users\George\.symfony\log\e79ad2f4b30a2f0a35c3b5ab08772770b382a3d6.log
PID 19324: C:\php\php-cgi.exe -b 62927 -d error_log=C:\Users\George\.symfony\log\e79ad2f4b30a2f0a35c3b5ab08772770b382a3d6.log
PID 17968: C:\php\php-cgi.exe -b 50197 -d error_log=C:\Users\George\.symfony\log\e79ad2f4b30a2f0a35c3b5ab08772770b382a3d6.log
PID 14040: C:\php\php-cgi.exe -b 55075 -d error_log=C:\Users\George\.symfony\log\e79ad2f4b30a2f0a35c3b5ab08772770b382a3d6.log
Environment Variables
None
In the Windows OS, the log files are kept in %USERPROFILE%.symfony. There's most likely a similar location in your home directory. Deleting all the contents of that directory allowed a new Windows Terminal app to show:
PS G:\workspace> symfony server:status
Local Web Server
Not Running
Workers
No Workers
Environment Variables
None
do symfony serve:stopto stopped the server and do against symfony serve to run the server good luck
I have a dockerised Nginx server created with openresty base image. When a particular endpoint is called it need to update nginx config dynamically. For the changes to reflect I am trying to reload the nginx soon after the changes in config.
with in the container i am able to reload nginx server using /usr/local/openresty/nginx/sbin/nginx -s reload
when i try to use the same with in lua as below ,It doesn't shoot any error but the config changes aren't getting reflected.
os.execute("/usr/local/openresty/nginx/sbin/nginx -s reload ")
You can skip calling nginx altogether and just send a HUP signal to the master process using LuaJITs FFI.
local process = require 'ngx.process'
local ffi = require 'ffi'
ffi.cdef 'int kill(int pid, int sig);'
ffi.C.kill(process.get_master_pid(), 1)
However, this doesn't fix the permissions problem.
One idea that could work is:
Set up a named pipe with mkfifo and make it so your nginx-user can write to it
Enable the Priviliged Agent worker process.
Set the privileged worker up to listen for input on the named pipe (for example using the ngx.pipe module to open cat and waiting for input) and send a HUP signal to the master process
Change your os.execute code to instead write some line of text into the named pipe to have the privileged agent reload the server.
EDIT: If you dislike the cat hack, you might want to have a look at https://github.com/slact/ngx_lua_ipc
It might be possible to use IPC to keep the whole thing self-contained within a single nginx server instance, without any file access.
This command would be run with nginx worker process privileges, and you need to be a root in order to execute this command. You can try to make a particular script for this (lets assume its name would be /usr/local/openresty/nginx/sbin/reload-nginx.sh:
#!/bin/sh
/usr/local/openresty/nginx/sbin/nginx -s reload
set the owner of this script no nginx process user (lets assume its name is nginx), and set the suid bit on this script
chown nginx /usr/local/openresty/nginx/sbin/reload-nginx.sh
chmod +x /usr/local/openresty/nginx/sbin/reload-nginx.sh
chmod u+s /usr/local/openresty/nginx/sbin/reload-nginx.sh
and try to execute this script from your lua code:
os.execute("/usr/local/openresty/nginx/sbin/nginx-reload.sh")
Below is by code for spawing a fcgi script for nginx.
spawn-fcgi -d /home/ubuntu/workspace -f /home/ubuntu/workspace/index.py -a 127.0.0.1 -p 9001
Now, lets I want to make changes to the index.py script and reload with out bring down the system. How do reload the spawned program so the next connections are using the updated program while the others finish? For now I am killing the spawned process and running command again. I am hoping for something more graceful.
I tried this by the way.
sudo kill -1 `sudo lsof -t -i:9001
I have recently made something similar for node.js.
The idea is to have index.py as a very simple bootstrap script (which doesnât actually change much over time). It should catch SIGHUP, and reload/reread the application files (which are expected to change frequently).
I am writing a file syncing application where I collect event from the filesystem whenever the file is modified and than later I copy it over to remote share via rsync over ssh. In my setup I have a slot which is connected to a QTimer. Each 5 seconds I pick a file from a sqlite db for synchronization and start a QProcess::start with the following parameters
/usr/bin/rsync -a /aufs/another-test-folder/testfile286.txt --rsh="ssh -p 8023" user#myserver.de:/home/neox/another-test-folder/testfile286.txt --rsync-path="mkdir -p /home/neox/another-test-folder && rsync"
I have at most 2 rsync processes running in parallel. This results in a process tree:
MyApp
\_rsync
| \_ssh
|_rsync
\_ssh
The problem is that sometimes the application hangs and the ps says that ssh processes have gone zombie. First I have tried to kill MyApp with SIGKILL but no luck. Than I moved on to kill rsync and ssh but still no luck. The whole tree hangs. And if I try to start the daemon from another console or even try to ssh to another box, I can't. My idea here is that somewhere ssh blocks some IO resources. Any idea how to solve this?
P.S. This happens randomly and not often