My Raspbian doesn't reboot via a Python application - python

I am desperately trying to find out a way to force my Raspberry Pi running Raspbian to restart when a certain condition is met (Python script), however I got no success so far...
I have tried the following statements by using popen:
sudo reboot -i -p
sudo reboot -f
sudo shutdown -r -f now
I thought the problem could be calling it through the Python application itself, therefore I wrote a small C program to kill all running Python application and then reboot, but no success...
My Raspberry is enough powered (Red LED is always on) and all commands I described above work fine when called directly from the command window.
Any help is appreciated!
Thanks,
EDITED:
Adding my python script as required:
from subprocess import Popen, PIPE
def reboot():
echo.echo("Rebooting...")
db.write_alarm(get_alarm_status())
upload.upload_log()
reboot_statement = "sudo shutdown -r -f now"
popen_args = reboot_statement.split(" ")
Popen(popen_args, stdout=PIPE, stderr=PIPE)

Try this:
create a file called reboot.py with the following contents:
import os
os.system("shutdown -r now")
then call it like this:
sudo python reboot.py
Assuming this works you can probably invoke your original script with sudo to get it to work.

You should pass shell=True id you want the shell to process the arguments
Popen("sudo shutdown -r -f now", stdout=PIPE, stderr=PIPE, shell=True)

Related

Sleepwatcher on OS X 10.11 not executing script on wake

In installed Sleepwatcher 2.2 on OS X 10.11 and launching it via LaunchD as an agent.
It launches okay and shows up in the activity monitor.
However, I want it to fire off a python script when the computer wakes up.
My installation commands are as follows.
sudo mkdir -p /usr/local/sbin /usr/local/share/man/man8
sudo cp ~/Desktop/sleepwatcher_2.2/sleepwatcher /usr/local/sbin
sudo cp ~/Desktop/sleepwatcher_2.2/sleepwatcher.8 /usr/local/share/man/man8
sudo cp ~/Desktop/sleepwatcher_2.2/sleepwatcher/config/rc.sleep /etc
sudo cp ~/Desktop/sleepwatcher_2.2/sleepwatcher/config/rc.wakeup /etc
sudo cp ~/Desktop/sleepwatcher_2.2/sleepwatcher/config/de.bernhard-baehr.sleepwatcher-20compatibility-localuser.plist /Library/LaunchAgents
chmod +x /etc/rc.sleep
chmod +x /etc/rc.wakeup
chmod +x /usr/local/bin/test.py
My rc.wakeup file is as follows.
#!/bin/sh
/usr/local/bin/python3 /usr/local/bin/test.py
When executing Sleepwatcher at the terimnal window by typing in the following, it seems to work.
/usr/local/sbin/sleepwatcher --verbose --wakeup /usr/local/bin/test.py
However, when trying to run it as a start-up item under LaunchD, it does not seem to work execute my python script.
I have search all over and cannot figure out why it is not working when being launched in LaunchD.
Has anybody ran into this type of problem?
Thanks in advance.
I encountered similar problems so I took a different approach using another open source tool called Hammerspoon. It can provide for automation of bunch of things on MacOS including sleep/wake events. It's quite simple to replicate sleepwatcher's functionality by adding the following to Hammerspoon's ~/.hammerspoon/init.lua (or create a 'spoon') script that triggers when the machine wakes or sleeps and calls the corresponding wake and sleep scripts (in e.g. /Users/username/scripts - ensure username is changed) from sleepwatcher:
function caffeinateWatcher(eventType)
if (eventType == hs.caffeinate.watcher.systemWillSleep or
eventType == hs.caffeinate.watcher.systemWillPowerOff) then
print ("WillSleep...")
-- Execute sleep script
hs.task.new("/Users/username/scripts/rc.sleep", nil):start()
elseif (eventType == hs.caffeinate.watcher.systemDidWake) then
print ("Woken...")
-- Execute wake script
hs.task.new("/Users/username/scripts/rc.wake", nil):start()
end
end
sleepWatcher = hs.caffeinate.watcher.new(caffeinateWatcher)
sleepWatcher:start()
Note if you want Hammerspoon to launch the shell scripts you need to ensure they start with the standard bash shell header #!/bin/bash.

Fabric run command - start sh script on the remote & leaving the remote script running [duplicate]

Through Fabric, I am trying to start a celerycam process using the below nohup command. Unfortunately, nothing is happening. Manually using the same command, I could start the process but not through Fabric. Any advice on how can I solve this?
def start_celerycam():
'''Start celerycam daemon'''
with cd(env.project_dir):
virtualenv('nohup bash -c "python manage.py celerycam --logfile=%scelerycam.log --pidfile=%scelerycam.pid &> %scelerycam.nohup &> %scelerycam.err" &' % (env.celery_log_dir,env.celery_log_dir,env.celery_log_dir,env.celery_log_dir))
I'm using Erich Heine's suggestion to use 'dtach' and it's working pretty well for me:
def runbg(cmd, sockname="dtach"):
return run('dtach -n `mktemp -u /tmp/%s.XXXX` %s' % (sockname, cmd))
This was found here.
As I have experimented, the solution is a combination of two factors:
run process as a daemon: nohup ./command &> /dev/null &
use pty=False for fabric run
So, your function should look like this:
def background_run(command):
command = 'nohup %s &> /dev/null &' % command
run(command, pty=False)
And you can launch it with:
execute(background_run, your_command)
This is an instance of this issue. Background processes will be killed when the command ends. Unfortunately on CentOS 6 doesn't support pty-less sudo commands.
The final entry in the issue mentions using sudo('set -m; service servicename start'). This turns on Job Control and therefore background processes are put in their own process group. As a result they are not terminated when the command ends.
For even more information see this link.
you just need to run
run("(nohup yourcommand >& /dev/null < /dev/null &) && sleep 1")
DTACH is the way to go. It's a software you need to install like a lite version of screen.
This is a better version of the "dtach"-method found above, it will install dtach if necessary. It's to be found here where you can also learn how to get the output of the process which is running in the background:
from fabric.api import run
from fabric.api import sudo
from fabric.contrib.files import exists
def run_bg(cmd, before=None, sockname="dtach", use_sudo=False):
"""Run a command in the background using dtach
:param cmd: The command to run
:param output_file: The file to send all of the output to.
:param before: The command to run before the dtach. E.g. exporting
environment variable
:param sockname: The socket name to use for the temp file
:param use_sudo: Whether or not to use sudo
"""
if not exists("/usr/bin/dtach"):
sudo("apt-get install dtach")
if before:
cmd = "{}; dtach -n `mktemp -u /tmp/{}.XXXX` {}".format(
before, sockname, cmd)
else:
cmd = "dtach -n `mktemp -u /tmp/{}.XXXX` {}".format(sockname, cmd)
if use_sudo:
return sudo(cmd)
else:
return run(cmd)
May this help you, like it helped me to run omxplayer via fabric on a remote rasberry pi!
You can use :
run('nohup /home/ubuntu/spider/bin/python3 /home/ubuntu/spider/Desktop/baidu_index/baidu_index.py > /home/ubuntu/spider/Desktop/baidu_index/baidu_index.py.log 2>&1 &', pty=False)
nohup did not work for me and I did not have tmux or dtach installed on all the boxes I wanted to use this on so I ended up using screen like so:
run("screen -d -m bash -c '{}'".format(command), pty=False)
This tells screen to start a bash shell in a detached terminal that runs your command
You could be running into this issue
Try adding 'pty=False' to the sudo command (I assume virtualenv is calling sudo or run somewhere?)
This worked for me:
sudo('python %s/manage.py celerycam --detach --pidfile=celerycam.pid' % siteDir)
Edit: I had to make sure the pid file was removed first so this was the full code:
# Create new celerycam
sudo('rm celerycam.pid', warn_only=True)
sudo('python %s/manage.py celerycam --detach --pidfile=celerycam.pid' % siteDir)
I was able to circumvent this issue by running nohup ... & over ssh in a separate local shell script. In fabfile.py:
#task
def startup():
local('./do-stuff-in-background.sh {0}'.format(env.host))
and in do-stuff-in-background.sh:
#!/bin/sh
set -e
set -o nounset
HOST=$1
ssh $HOST -T << HERE
nohup df -h 1>>~/df.log 2>>~/df.err &
HERE
Of course, you could also pass in the command and standard output / error log files as arguments to make this script more generally useful.
(In my case, I didn't have admin rights to install dtach, and neither screen -d -m nor pty=False / sleep 1 worked properly for me. YMMV, especially as I have no idea why this works...)

Run python script from rc.local does not execute

I want to run a python script on boot of ubuntu 14.04LTS.
My rc.local file is as follows:
sudo /home/hduser/morey/zookeeper-3.3.6/bin/zkServer.sh start
echo "test" > /home/hduser/test3
sudo /home/hduser/morey/kafka/bin/kafka-server-start.sh /home/hduser/morey/kafka/config/server.properties &
echo "test" > /home/hduser/test1
/usr/bin/python /home/hduser/morey/kafka/automate.py &
echo "test" > /home/hduser/test2
exit 0
everything except my python script is working fine even the echo statement after running the python script, but the python script doesnt seem to run.
My python script is as follows
import sys
from subprocess import Popen, PIPE, STDOUT
cmd = ["sudo", "./sbt", "project java-examples", "run"]
proc = Popen(cmd, shell=False, stdout=PIPE, stdin=PIPE, stderr=STDOUT)
proc.communicate(input='1\n')
proc.stdin.close()
which works perfectly fine if executed individually.
I went through the following questions , link
I did a lot of research but couldn't find a solution
Edit : echo statements are for testing purpose only, and the second actual command (not considering the echo statements) is starting a server which keeps on running, and even the python script starts a listener which runs on an infinite loop, if this is any help
The Python script tries to launch ./sbt. Are you sure of what if the current directory when rc.local runs? The rule is always use absolute paths in system scripts
Do not run the Python script in background, run it in foreground. Do not exit from its parent script. Better call another script from "rc.local" that does all the job of "echo" and script launching.
Run that script from "rc.local"; not in background (no &).
You do not need "sudo" as "rc.local" is run as root.
If you want to run python script at system boot there is an alternate solution which i have used.
1:Create sh file like sample.sh and copy paste following content
#!/bin/bash
clear
python yourscript.py
2:Now add a cron job at reboot.If you are using linux you can use as following
a:Run crontab -e(Install sudo apt-get install cron)
b:#reboot /full path to sh file > /home/path/error.log 2>&1
And restart your device

Opening a terminal application from python and running custom scripts inside it

I'm working with a software called dc_shell that has a terminal command (also called dc_shell) on a CentOS Linux server. when I run dc_shell command, I'm connected to its terminal and I'm able to run scripts/commands inside it. (This is all done manually)
So the real problem is that I want to do this task all from a Python program. Meaning that I have a Python code which does some task, and after that has to open dc_shell and run some commands inside it.
I have used subprocess.Popen before and this doesn't have any problem when I run commands like ls or other general terminal commands. But when I run dc_shell command it seems like it crashes and nothing happens, and when I try to terminate the session I get the following errors in my terminal.
Here's my code:
def run_scripts():
commandtext = 'cd ..; dc_shell-xg-t; set_app_var link_library "slow.db"; set_app_var target_library "slow.db"; set_app_var symbol_library "tsmc18.sdb";'
print(commandtext)
process = subprocess.Popen(commandtext,stdout=subprocess.PIPE, shell=True)
proc_stdout = process.communicate()[0].strip()
print(proc_stdout)
and the output is:
cd ..; dc_shell-xg-t; set_app_var link_library "slow.db"; set_app_var target_library "slow.db"; set_app_var symbol_library "tsmc18.sdb";
and nothing happens... and after terminating I get:
[User#server python]$ /bin/sh: set_app_var: command not found
/bin/sh: set_app_var: command not found
/bin/sh: set_app_var: command not found
Do you need to use dc_shell to run your commands?
If so, that should be your executable and the rest of commands your arguments.
You should never use shell=True due to security considerations (the warning in the 2.x docs for subprocess seems much clearer to me).

python subprocess output on nohup

Trying to monitor the available physical disc space of a remote machine using a python script, which executes the df -h . command using subprocess.popen.
import subprocess
import time
command = 'ssh remoteserver "df -h ."'
while True:
proc = subprocess.Popen(command,shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
output,err=proc.communicate()
print output
print err
time.sleep(60)
The script runs fine and prints the output to the terminal when run from command line
$> python2.7 script.py
Filesystem Size Used Avail Use% Mounted on
remoteserver:/home/user
555G 447G 109G 81% /home
The scripts does not produce any output or seems to be blocking when the script is started with nohup command.
$> nohup python2.7 script.py &
Would like the script to work and fetch the disc space of remote machine using the above script when started in nohup.
I'm not 100% sure of the underlying issue here, but when you invoke NOHUP in the shell, it's disconnected some of the STDIN/STDOUT from the terminal process, which I suspect it causing some of this interactions you're seeing.
Given that you're doing this from a remote machine, I'd actually recommend you look at using something like Fabric as a library to do what you're after. It's pretty straightforward, and does most of the handling of terminal sessions as well as closing things down nicely for you when you're complete.
something like:
from fabric import api
from fabric.api import env
import fabric
env.host_string = '%s#%s' % (username, remote_host)
env.disable_known_hosts = True
env.password = password
fabric.state.output['stdout'] = False
fabric.state.output['stderr'] = False
results = api.run('df -h')
You might try sending stdin=subprocess.PIPE to the subprocess command, then calling proc.stdin.close() on the next line, before the communicate() call. Or you can try changing the command to 'ssh remoteserver "df -h ." </dev/null'. Others report using FNULL = open(os.devnull, 'r') and passing in FNULL to the stdin= argument, but I'm not sure if you need to call FNULL.close() after or not.
SSH is most likely waiting for input for some reason when it is run from nohup. Perhaps it is unable to authenticate in the nohup environment and is asking for password input?
To make sure SSH is not waiting for input, try adding -o "BatchMode yes" to the ssh command and see if there are some clues in the output/error from the subprocess communicate call.

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