With Paramiko , you can do a ssh2 secure connection via python, you can also use remote command, file transfer and ssh proxy, etc.

Install paramiko:

To install paramiko, we need the dependencies python-dev ,and modules pycrypto and ecdsa.

apt-get install python-dev

Centos:

yum -y install python-devel

pip install pycrypto ecdsa

Then install paramiko

pip install paramiko

To test the success of the installation:

# python
Python 2.6.6 （r266： 84292， Jul 10 2013， 22： 48： 45）
[GCC 4.4.7 20120313 （Red Hat 4.4.7-3） ] on linux2
Type "help"， "copyright"， "credits" or "license" for more information.
>>> import paramiko
>>>

If there is no error message, then it means you installed the module successfully.

core class

There are two core classes: SSHClient class and SFTPClient class.

1, SSHClient class

We can use the methods to connect, transport, build channel, and verify.

Here is a simple example:

hostname='192.168.10.110'
username='administrator'
password='adminpassword'
paramiko.util.log_to_file('syslogin.log')   #write the paramiko logging to a log file 
client=SSHClient()                          #Create a ssh client objectclient.load_system_host_keys()              #Get the host key from ./ssh/know_hosts, if the host is not in this file, use following line and comment this line out.
client.set_missing_host_key_policy(paramiko.AutoAddPolicy())   # Automatically add the unknown host to the known_host
client.connect(hostname=hostname, username=username, password=password)
stdin, stdout, stderr=client.exec_command('free -m') #execute the command 'free -m' to show the free memory
print stdout.read()
stdout.readlines()
client.close() #terminate the ssh connection

set_missing_host_key_policy(policy) : Set policy to use when connecting to servers without a known host key.

Specifically:

A policy is a “policy class” (or instance thereof), namely some subclass of MissingHostKeyPolicy such as RejectPolicy (the default), AutoAddPolicy, WarningPolicy, or a user-created subclass.

Reference: http://docs.paramiko.org/en/2.4/api/client.html

Parameters:

hostname (str) – the server to connect to port (int) – the server port to connect to username (str) – the username to authenticate as (defaults to the current local username) password (str) – Used for password authentication; is also used for private key decryption if passphrase is not given. passphrase (str) – Used for decrypting private keys. pkey (PKey) – an optional private key to use for authentication key_filename (str) – the filename, or list of filenames, of optional private key(s) and/or certs to try for authentication timeout (float) – an optional timeout (in seconds) for the TCP connect allow_agent (bool) – set to False to disable connecting to the SSH agent look_for_keys (bool) – set to False to disable searching for discoverable private key files in ~/.ssh/ compress (bool) – set to True to turn on compression sock (socket) – an open socket or socket-like object (such as a Channel) to use for communication to the target host gss_auth (bool) – True if you want to use GSS-API authentication gss_kex (bool) – Perform GSS-API Key Exchange and user authentication gss_deleg_creds (bool) – Delegate GSS-API client credentials or not gss_host (str) – The targets name in the kerberos database. default: hostname gss_trust_dns (bool) – Indicates whether or not the DNS is trusted to securely canonicalize the name of the host being connected to (default True). banner_timeout (float) – an optional timeout (in seconds) to wait for the SSH banner to be presented. auth_timeout (float) – an optional timeout (in seconds) to wait for an authentication response.

2. exec_command

Execute a command on the SSH server. A new Channel is opened and the requested command is executed. The command’s input and output streams are returned as Python file-like objects representing stdin, stdout, and stderr.

Parameters:

command (str) – the command to execute bufsize (int) – interpreted the same way as by the built-in file() function in Python timeout (int) – set command’s channel timeout. See Channel.settimeout environment (dict) –a dict of shell environment variables, to be merged into the default environment that the remote command executes within. Warning Servers may silently reject some environment variables; see the warning in Channel.set_environment_variable for details.

Returns:

the stdin, stdout, and stderr of the executing command, as a 3-tuple