i use the following class to run commands via SSH on a remote server:
class ShellHandler:
def __init__(self, host, user, psw):
self.ssh = paramiko.SSHClient()
self.ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
self.ssh.connect(host, username=user, password=psw, port=22)
channel = self.ssh.invoke_shell()
self.stdin = channel.makefile('wb')
self.stdout = channel.makefile('r')
self.shell = channel
def __del__(self):
self.ssh.close()
def ftp(self):
ftp_client = self.ssh.open_sftp()
return ftp_client
def execute(self, cmd):
"""
:param cmd: the command to be executed on the remote computer
:examples: execute('ls')
execute('finger')
execute('cd folder_name')
"""
cmd = cmd.strip('\n')
self.stdin.write(cmd + '\n')
finish = 'end of stdOUT buffer. finished with exit status'
echo_cmd = 'echo {} $?'.format(finish)
self.stdin.write(echo_cmd + '\n')
shin = self.stdin
self.stdin.flush()
shout = []
sherr = []
exit_status = 0
for line in self.stdout:
if str(line).startswith("FINISHED"): # add "; echo FINISHED" to the end of commands that take much longer to excute
break
if str(line).startswith(cmd) or str(line).startswith(echo_cmd):
# up for now filled with shell junk from stdin
shout = []
elif str(line).startswith(finish):
# our finish command ends with the exit status
exit_status = int(str(line).rsplit(maxsplit=1)[1])
if exit_status:
# stderr is combined with stdout.
# thus, swap sherr with shout in a case of failure.
sherr = shout
shout = []
break
else:
# get rid of 'coloring and formatting' special characters
shout.append(re.compile(r'(\x9B|\x1B\[)[0-?]*[ -/]*[@-~]').sub('', line).
replace('\b', '').replace('\r', ''))
# first and last lines of shout/sherr contain a prompt
if shout and echo_cmd in shout[-1]:
shout.pop()
if shout and cmd in shout[0]:
shout.pop(0)
if sherr and echo_cmd in sherr[-1]:
sherr.pop()
if sherr and cmd in sherr[0]:
sherr.pop(0)
return shin, shout, sherr
i run my commands as follows:
server= ShellHandler(ip_address, username, password)
cmd = avamar.execute("whoami")
output = cmd[1]
it almost works most of the time, but sometimes it gets stuck and when I check my log file, this is all it says:
DEBUG - [chan 0] Unhandled channel request "keepalive@openssh.com"
what does this output mean, and how to fix it. I'd appreciate it if anyone can point me in the right direction.
