we are using python3 on our Linux machines
I am trying to pass the variable IP , in cmd
#!/usr/bin/python3
import sys, os, logging
import subprocess
IP = '127.0.0.1'
COMMAND = "ping -c 3 IP"
subprocess.call(COMMAND, shell=True)
subprocess.Popen(COMMAND,stdin=subprocess.PIPE,stdout=subprocess.PIPE, shell=True).stdout.read()
since we get the error about ping: unknown host IP
I am thinking how to pass the IP variable , so later I can execute the cmd with subprocess.call and subprocess.Popen
Instead of providing COMMAND as a string, it's safer to provide it as a list instead and leave shell at its default value of False. That way, you don't have to perform shell escaping in case any arguments contain "special" characters like spaces:
COMMAND = ["ping", "-c", "3"]
subprocess.call(COMMAND + [IP])
You need to insert the contents of IP into COMMAND. Here, you can simply add the strings like this:
COMMAND = "ping -c 3 " + IP
Related
I have an issue where when I print a command that I want the python script to run, it prints in perfect syntax, however, when I try to use that exact same variable in order to run the command using os.system() it won't run and gives me an error. See Below:
wholecommand = '''python3 mysshpass.py --password "%s" ssh %s "%s" ''' % (password, sshprefix, runcommand)
print(wholecommand)
response = os.system(wholecommand)
So in this instance I've defined the command I want to run based off of some random variables but when I run this code it returns with the following:
python3 mysshpass.py --password "***" ssh root#10.245.10.72 "echo -e '***
***' | passwd"
ssh: Could not resolve hostname \357\273\27710.245.10.72: Name or service not known
The issue here is that for whatever reason my script is inserting \357\273\277 into the thread where the ip address goes and I just can't figure out why.
I am using this code for executing command on remote server.
import subprocess
import sys
COMMAND="ls"
ssh = subprocess.Popen(["ssh", "%s" % HOST, COMMAND],
shell=False,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
result = ssh.stdout.readlines()
if result == []:
error = ssh.stderr.readlines()
print >>sys.stderr, "ERROR: %s" % error
else:
print result
When I try to execute this script, I get prompt for password. Is there any way I could avoid it, for example, can I enter password in script somehow? Also, password should be encrypted somehow so that people who have access to the script cannot see it.
Why make it so complicated? Here's what I suggest:
1) Create a ssh config section in your ~/.ssh/config file:
Host myserver
HostName 50.50.50.12 (fill in with your server's ip)
Port xxxx (optional)
User me (your username for server)
2) If you have generated your ssh keypair do it now (with ssh-keygen). Then upload with:
$ ssh-copy-id myserver
3) Now you can use subprocess with ssh. For example, to capture output, I call:
result = subprocess.check_output(['ssh', 'myserver', 'cat', 'somefile'])
Simple, robust, and the only time a password is needed is when you copy the public key to the server.
BTW, you code will probably work just fine as well using these steps.
One way is to create a public key, put it on the server, and do ssh -i /path/to/pub/key user#host or use paramiko like this:
import paramiko
import getpass
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
p = getpass.getpass()
ssh.connect('hostname', username='user', password=p)
stdin, stdout, stderr = ssh.exec_command('ls')
print stdout.readlines()
ssh.close()
You should use pexpect or paramiko to connect to remote machine,then spawn a child ,and then run subprocess to achieve what you want.
Here's what I did when encountering this issue before:
Set up your ssh keys for access to the server.
Set up an alias for the server you're accessing. Below I'll call it remote_server.
Put the following two lines at the end of ~/.bash_profile.
eval $(ssh-agent -s)
ssh-add
Now every time you start your shell, you will be prompted for a passphrase. By entering it, you will authenticate your ssh keys and put them 'in hand' at the start of your bash session. For the remainder of your session you will be able to run commands like
ssh remote_server ls
without being prompted for a passphrase. Here ls will run on the remote server and return the results to you. Likewise your python script should run without password prompt interruption if you execute it from the shell.
You'll also be able to ssh to the server just by typing ssh remote_server without having to enter your username or password every time.
The upside to doing it this way is that you should be doing this anyway to avoid password annoyances and remembering funky server names :) Also you don't have to worry about having passwords saved anywhere in your script. The only potential downside is that if you want to share the python script with others, they'll have to do this configuring as well (which they should anyway).
You don't really need something like pexpect to handle this. SSH keys already provide a very good and secure solution to this sort of issue.
The simplest way to get the results you want would probably be to generate an ssh key and place it in the .ssh folder of your device. I believe github has a pretty good guide to doing that, if you look into it. Once you set up the keys correctly on both systems, you won't actually have to add a single line to your code. When you don't specify a password it will automatically use the key to authenticate you.
While subprocess.Popen might work for wrapping ssh access, this is not the preferred way to do so.
I recommend using paramiko.
import paramiko
ssh_client = paramiko.SSHClient()
ssh_client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh_client.connect(server, username=user,password=password)
...
ssh_client.close()
And If you want to simulate a terminal, as if a user was typing:
chan=ssh_client.invoke_shell()
def exec_cmd(cmd):
"""Gets ssh command(s), execute them, and returns the output"""
prompt='bash $' # the command line prompt in the ssh terminal
buff=''
chan.send(str(cmd)+'\n')
while not chan.recv_ready():
time.sleep(1)
while not buff.endswith(prompt):
buff+=ssh_client.chan.recv(1024)
return buff[:len(prompt)]
Example usage: exec_cmd('pwd')
If you don't know the prompt in advance, you can set it with:
chan.send('PS1="python-ssh:"\n')
You could use following.
import subprocess
import sys
COMMAND="ls"
ssh = subprocess.Popen("powershell putty.exe user#HOST -pw "password", stdout=PIPE, stdin=PIPE, stderr=STDOUT)
result = ssh.stdout.readlines()
if result == []:
error = ssh.stderr.readlines()
print >>sys.stderr, "ERROR: %s" % error
else:
print result
I want to run my python script from my local machine. But the python script named script.py is in remote server and it has some arguments and parameters.
I have tried:
#!/usr/bin/python
import paramiko
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect(hostname='x.x.x.x', port=22, username='root', password='passwd')
stdin, stdout, stderr=ssh.exec_command('python /root/file/script.py') #It has some argument I want to use them from my local machine
for i in stdout.readlines():
print i.strip('\r\n')
ssh.close()
script.py has some arguments. how should I change this script in order to use arguments of script.py from my local machine?
It is more tricky than one would think, thanks to ssh not supporting argument lists:
import sys
try:
from pipes import quote # python 2
except ImportError:
from shlex import quote # python 3
ssh.exec_command('python /root/file/script.py ' +
' '.join([quote(i) for i in sys.argv[1:]])
)
When running python myprogram.py argument\ with" quotes\" and spaces", this should pass 'argument with quotes" and spaces' as 1 argument to the other program. Though I wouldn't vouch for paramiko always doing the right thing.
I need to ssh into the server and execute few commands and process the response using subprocess. Here's my code
command = 'ssh -t -t buildMachine.X.lan; sudo su - buildbot ; build-set sets/set123'
print "submitting command"
result = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE, stdin=subprocess.PIPE)
print "got response"
response,err = result.communicate()
print response
This is getting stuck. I have seen other threads talking about passing a list instead of string to subprocess and removing shell=True.. I did that too but didn't work.
Ultimately I need the result of last command i.e. build-set in order to extract some information out of it.. help?
I figured the solution by using univerio's comment
The command needs to be
command = 'ssh -t -t buildMachine.X.lan \'sudo su - buildbot \'build-set sets/set123\'\''
Individual commands are like argument to previous command. This works.
I have change my hosts file,so how to change hostname.my system is ubuntu.
eg my hosts file:
192.168.0.100 host1.mydomain.com
192.168.0.101 host2.mydomain.com
I wanna the hostname file under /etc/hostname of host1 to host1.mydomain.com,the hostname file of host2 to host2.mydomain.com
how to do that using fabric?
I have to ssh every host and edit the hostname file,does fabric can do this?
I didn't mean to use hostname command but to edit the /etc/hostname file.
I mean how to use fabric to do that:
such as:
def update_hostname():
get("/etc/hosts","hosts")
hosts_content = file("hosts")
**hostname = ·get the hostname corespond to ip·**
get("/etc/hostname","hostname")
update `hostname file`
put("hostname","/etc/hostname")
how get the ip? because fabric do the job on every host, and the hostname is correspond to each host. I need to know the which host the job is working and then get the ip back,then get the hostname correspond the the ip,and final update the hostname file.
Fabric is just a SSH wrapper, so what you're looking at is LINUX specific, not frabric or python specific.
from fabric.api import run
run('hostname your-new-name')
run('echo your-new-hostname > /etc/hostname')
And just do a run(..edit..) according to your linux dist?
Or just do:
from subprocess import Popen, PIPE
hosts = open('/etc/networking/hosts', 'rb')
for hostline in hosts.readlines():
ip, name = hostline.split(' ')
command = ['ssh', '-t', 'root#' + host.strip('\r\n ,;), ' ', "echo " + name.strip('\r\n ,;) + " > /etc/hostname",]
stdout, stderr = Popen(command, stdout=PIPE, stderr=PIPE).communicate()
hosts.close()
Note: /etc/networking/hosts might be placed somewhere else for you.
The important part here is that you loop through the /hosts file, and ssh to each machine echoing the given hostname to that machine.
def hostname():
'''
function to change the hostname of the ubuntu server
'''
server_hostname = prompt ("The Hostname for the server is :")
sed ("/etc/hostname", before='current hostname', after='%s' % (server_hostname), use_sudo=True,backup='')
sudo ("init 6")
This will change the hostname according to your choice.
in your fabric script you'll need to...
ssh into the machine as a user permitted to edit the hosts file ( via permissions or groups ). if you need to sudo into a user, search StackOverflow for issues regarding sudo and Fabric -- you'll need to tweak your fabfile to not prompt for a password.
fabric can have an awkward way to deal with reading/writing/opening files. you'll may be best off by cd into the right directory. something like...
with cd('/etc/')
run('echo new_hostname hostname')