Multihost actions toolbox


License
GPL-3.0+
Install
pip install stitches==0.15

Documentation

Stitches library

Overview

Stitches is a wrapper around Paramiko (https://github.com/paramiko/paramiko) and python-rpyc (http://rpyc.readthedocs.org/en/latest/). It allows you to create connections to remote hosts and perform various shell/python actions on remote hosts. The library has 3 main parts: Connection, Expect and Structure

Connection

Connection class represents connection to remote host.

Shell commands usage example: import stitches

  In [1]: con = stitches.connection.Connection('ec2host.eu-west-1.compute.amazonaws.com', key_filename='/home/user/.pem/eu-west-1-iam.pem', username='ec2-user')
  
  # Return value
  In [2]: con.recv_exit_status("ls -la /etc/passwd")
  Out[2]: 0

  In [3]: con.recv_exit_status("ls -la /non/existing/file")
  Out[3]: 2

  # Getting output
  In [4]: sin, sout, serr = con.exec_command("ls -la /etc/passwd /non/existing/file")

  In [5]: print sout.read()
  -rw-r--r--. 1 root root 1383 Sep  9 07:37 /etc/passwd

  In [6]: print serr.read()
  ls: cannot access /non/existing/file: No such file or directory

  # Timeout during command execution
  In [7]: print con.recv_exit_status("sleep 30", timeout=3)
  None

  # Some commands (e.g. sudo) require pty:
  In [1]: print con.recv_exit_status("sudo id", get_pty=True)
  0

RPyC example: # Built-in function open() on remote host In [1]: fd = con.rpyc.builtins.open('/etc/redhat-release')

 In [2]: print fd.read()
 Red Hat Enterprise Linux Server release 6.4 (Santiago)

 # Module on remote host
 In [3]: con.rpyc.modules.os.stat("/etc/passwd")
 Out[3]: posix.stat_result(st_mode=33188, st_ino=140905, st_dev=51777L, st_nlink=1, st_uid=0, st_gid=0, st_size=1383, st_atime=1382614681, st_mtime=1378726667, st_ctime=1378726667)

Expect

Expect class is being used for expect-like testing. Example:

 # Expect sub-string in output
 In [1]: stitches.expect.Expect.ping_pong(con, "cat /etc/redhat-release", 'Red Hat')
 Out[1]: True

 # Failure will raise ExpectFailed exception:
 In [2]: stitches.expect.Expect.ping_pong(con, "cat /etc/redhat-release", 'Debian')
 ---------------------------------------------------------------------------
 ExpectFailed                              Traceback (most recent call last)
 ...
 ExpectFailed: cat /etc/redhat-release
 Red Hat Enterprise Linux Server release 6.4 (Santiago)
 [ec2-user@ip-10-234-98-44 ~]$
 
 # Matching
 In [3]: stitches.Expect.enter(con, 'cat /etc/redhat-release')
 Out[3]: 24

 In [4]: stitches.expect.Expect.match(con, re.compile('.*release ([0-9,\.]*).*', re.DOTALL))
 Out[4]: ['6.4']

 # Run a command and expect an exit status (0 by default)
 In [5]: stitches.expect.Expect.expect_retval(con "cat /etc/redhat-release /foo")
 ---------------------------------------------------------------------------
 ExpectFailed                              Traceback (most recent call last)
 ...
 stitches.expect.ExpectFailed: Got 1 exit status (0 expected)
 cmd: cat /etc/redhat-release /foo
 stdout: Red Hat Enterprise Linux release 8.0 Beta (Ootpa)

 stderr: cat: /foo: No such file or directory

Structure

Structure class is being used to create whole testing setup with multiple hosts performing different roles. Structure is usually created based on YAML file:

Example YAML: Config: {param_a: a, param_b: b} Instances: - {private_hostname: hosta.compute.amazonaws.com, public_hostname: hosta.eu-west-1.compute.amazonaws.com, role: A_ROLE, username: ec2-user, key_filename: /home/user/.pem/eu-west-1-iam.pem} - {private_hostname: hostb.compute.amazonaws.com, public_hostname: hostb.eu-west-1.compute.amazonaws.com, role: B_ROLE, username: root, key_filename: /home/user/.pem/eu-west-1-iam.pem}

Usage example: In [1]: s = stitches.Structure()

 In [2]: s.setup_from_yamlfile('/tmp/str.yaml')
 
 # Now `Structure` object has connections to all instances, we can do whatever we want:

 In [3]: s.Instances['A_ROLE'][0].recv_exit_status('id')
 Out[3]: 0

 # And we have config as well:
 In [4]: s.config['param_a']
 Out[4]: 'a'

Dependencies

Stitches needs some external dependencies:

  • python-paramiko
  • python-plumbum
  • python-rpyc

python-paramiko version in Fedora-19 is OK, plumbum and rpyc should be at least:

  • python-plumbum-1.1.0_gitebe4cc4-2.fc18.noarch
  • python-rpyc-3.3.0git40daa0c6-2.fc18.noarch

Pre-built RPMs can be obtained here: https://rhuiqerpm.s3.amazonaws.com/index.html

Reporting issues

radek at redhat dot com