Created a hta application which when button is clicked it opens a linux server and executed pre defined commands.
The below list with 2 single word commands logs into linux server and runs the cmd. it is working fine.
But for the 3rd cmd df -kh | grep -i pmon, due to some issue i am unable to run those commmands.
scrip=["pwd","date","df -kh | grep -i pmon"];
for i in scrip:
proc=Popen("plink.exe -pw xxx un#zz.com pbrun ohsdba -u orinstance "+i,shell=True,stdout=PIPE,universal_newlines=True )
output=proc.stdout.read();
print(output)
time.sleep(2)
I get the following error.
'grep' is not recognized as an internal or external command,
operable program or batch file.
Since you've set shell=True, the pipe sign is probably interpreted locally, so it tries to run grep on your local Windows machine, instead of on the linux server.
You should consider quoting the command you want to run remotely. There are some suggestions on how to quote in Python here: Python module to shellquote/unshellquote?
Related
Overview
I'm trying to use python fabric to run an ssh command as root on a remote server.
The command: nohup ./foo &
foo is expected to command run for several days. I must be able to disassociate foo from fabric's remote ssh session, and put foo in the background.
The Fabric FAQ says you should use something like screen or tmux when you run your fabric script (which runs the backgrounded command). I tried that, but my fabric script still hung. foo is not hanging.
Question
How do I use fabric to run this command on a remote server without the script hanging: nohup ./foo &
Details
This is my script:
#!/bin/sh
# Credit: https://unix.stackexchange.com/a/20895/6766
if "true" : '''\'
then
exec "/nfs/it/network_python/$OSREL/bin/python" "$0" "$#"
exit 127
fi
'''
from getpass import getpass
import os
from fabric import Connection, Config
assert os.geteuid()==0, "ERROR: Must run as root"
for host in ['host1.foo.local', 'host2.foo.local']:
# Make an ssh connection to the host...
conn = Connection(host)
# The script always hangs at this line
result = conn.run('nohup ./foo &', warn=True, hide=True)
I always open a tmux session to run the aforementioned script in; even doing so, the script hangs when I get to conn.run(), above.
I'm running the script on a vanilla CentOS 6.5 VM; it runs under python 2.7.10 and fabric 2.1.
The Fabric FAQ is unclear... I thought the FAQ wanted tmux used on the local side when I executed the Fabric script.
The correct way to fix this problem is to replace nohup in the remote command, with screen -d -m <command>. Now I can run the whole script locally with no hangs (and I don't have to use tmux in the local term).
Explicitly, I have to rewrite the last line of my script in my question as:
# Remove &, and nohup...
result = conn.run('screen -d -m ./foo', warn=True, hide=True)
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).
I'm using python fabric to deploy binaries to an ec2 server and am attempting to run them in background (a subshell).
All the fabric commands for performing local actions, putting files, and executing remote commands w/o elevated privileges work fine. The issue I run into is when I attempt to run the binary.
with cd("deploy"):
run('mkdir log')
sudo('iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8080', user="root")
result = sudo('./dbserver &', user="root") # <---- This line
print result
if result.failed:
print "Running dbserver failed"
else:
print "DBServer now running server" # this gets printed despite the binary not running
After I login to the server and ps aux | grep dbserver nothing shows up. How can I get fabric to execute the binary? The same command ./dbserver & executed from the shell does exactly what I want it to. Thanks.
This is likey reated to TTY issues, and/or that you're attempting to background a process.
Both of these are discussed in the FAQ under these two headings:
http://www.fabfile.org/faq.html#init-scripts-don-t-work
http://www.fabfile.org/faq.html#why-can-t-i-run-programs-in-the-background-with-it-makes-fabric-hang
Try making the sudo like this:
sudo('nohup ./dbserver &', user=root, pty=False)
I need to run some bash commands via Fabric API (ssh).
I have the following String in my Python module:
newCommand = command + "'`echo -ne '\\015'"
When I print this string directly in Python the output is the expected:
command'`echo -ne '\015'
However, if I try to run this command via the Fabric API the command is somehow modified into this:
/bin/bash -l -c "command'\`echo -ne '\015'"
Notice the '\' before 'echo'. Why is this happenning? The '\' is breaking my command and I can't successfuly run the command.
ps: The prefix "/bin/bash -l -c" is expected since that's how Fabric works with SSH
This is not a valid shell command:
command'`echo -ne '\015'
Even if you add the missing backtick and single quote, it's nothing like writing "command" and pressing enter.
The context your command will be run in is basically what you'd get if you'd ssh and paste a command:
clientprompt$ ssh host
Welcome to Host, User
hostprompt$ <COMMAND HERE>
You should focus your efforts on finding a single command that does what you want, and not a series of keypresses that you could write to do it (that's not how ssh works).
I use python module pysftp to connect to remote server. Below you can see python code :
import pysftp
import sys
import sqr_common
srv = pysftp.Connection(host="xxxxxx", username="xxxx",
password="xxxxx")
command = "/usr/bin/bash"
command2="APSHOME=/all/aps/msc_2012; export APSHOME; "
srv.execute(command)
srv.execute(command2)
srv.close()
Problem is that command /usr/bin/bash is an infinite process , so my script will never be executed. Can anyone help me how to choose shell on remote server for example bash and execute command in bash on remote server?? Is there any pysftp function that allows me chosing shell??
try this
/usr/bin/bash -c "APSHOME=/all/aps/msc_2012; export APSHOME; "
This problem is not specific to Python, but more like how to execute commands under specific shell.
If you need to run only single command you can run using bash -c switch
bash -c "echo 123"
You can run multiple commands ; separated
bash -c "echo 123 ; echo 246"
If you need to many commands under a specific shell, remotely create a shell script file (.bash file) an execute it
bash myscript.bash