Demo NIOS script to execute remote (ssh) console commands using pexpect. The script allows for the execution of show commands, shutdown/reboot, and set promote_master.
It is implemented as a library or for use as a CLI that can be called, for example, via the ansible command module.
Python 3.7+
You can install the latest version of Python 3.x by downloading the appropriate installer for your system from python.org.
Note
If you are running MacOS Catalina (or later) Python 3 comes pre-installed. Previous versions only come with Python 2.x by default and you will therefore need to install Python 3 as above or via Homebrew, Ports, etc.
By default the python command points to Python 2.x, you can check this using the command:
$ python -V
To specifically run Python 3, use the command:
$ python3
Important
Mac users will need the xcode command line utilities installed to use pip3, etc. If you need to install these use the command:
$ xcode-select --install
Note
If you are installing Python on Windows, be sure to check the box to have Python added to your PATH if the installer offers such an option (it's normally off by default).
Non-standard modules:
- pexpect
Complete list of modules:
import logging import sys import argparse import configparser import pexpect
The simplest way to install and maintain the tools is to clone this repository:
% git clone https://github.com/ccmarris/nios_console_cmds
Alternative you can download as a Zip file.
The script utilise a the same gm.ini file format as the demo nios api scripts for simplicity. However, since this connects to a specified member via remote console, this is used only for administrator credentials.
The gm.ini file is used by the scripts to define the details to connect to to Grid Master. A sample inifile is provided and follows the following format:
[NIOS] gm = '192.168.1.10' api_version = 'v2.12' valid_cert = 'false' user = 'admin' pass = 'infoblox'
You can use either an IP or hostname for the Grid Master. This inifile should be kept in a safe area of your filesystem.
Use the --config/-c option to override the default ini file.
The script support -h or --help on the command line to access the options available:
% ./nios_console_cmds.py --help
usage: nios_console_cmds.py [-h] [-c CONFIG] -m MEMBER -C COMMAND [-p] [-D DELAY] [-d]
NIOS Remote Comsole Access
optional arguments:
-h, --help show this help message and exit
-c CONFIG, --config CONFIG
Overide Config file
-m MEMBER, --member MEMBER
Name or IP of Grid Member
-C COMMAND, --command COMMAND
show command or promote_master
-p, --promote Promote GMC to GM
-D DELAY, --delay DELAY
Set delay on promotion
-d, --debug Enable debug messages
Run a show command against a Grid Member:
% ./nios_console_cmds.py --config gm.ini -m 10.10.10.10 --command 'show status'
Enable debug:
% ./nios_console_cmds.py --config gm.ini -m 10.10.10.10 --command 'show status' --debug
Reboot member:
% ./nios_console_cmds.py --config gm.ini -m 10.10.10.10 --command 'reboot' --yes
Note
Where a command needs a confirmation use --yes to send a confirmation to proceed. Otherwise a no response will be sent in response to the command.
Promoting a GMC to GM, should always be performed after a concious decision has been made to perform a promotion. The intention here is not to allow for a fully automated promotion of a GMC.
To use the promotion function, a specific command promote_master is used. An additional safeguard must also be used to enable the command by adding the --promote option.
Examples:
% ./nios_console_cmds.py -c ~/configs/localgm.ini -m 10.101.101.101 -C 'promote_master' WARNING:root:Safeguard prevented promotion % ./nios_console_cmds.py -c ~/configs/localgm.ini -m 10.101.101.101 -C 'promote_master' --promote ERROR: Promotion failed ERROR: set promote_master Unable to promote: This member is already the grid master % ./nios_console_cmds.py -c ~/configs/localgm.ini -m 10.101.101.101 -C 'promote_master' --promote
This project is licensed under the 2-Clause BSD License - please see LICENSE file for details.
Thanks to Alex Del Rio for bringing the use case and to both Alex and Steve Makousky for testing in their labs.