I’m planning a small blog post series about Cisco configuration backup with
Netbox and Gitlab.
My idea is to “control” which devices are backed up by Netbox with
Device Type, Site, IPv4 address and Status (“Active”).
Based on above information the script should then login with SSH to the
devices, send a couple of commands like banner, wr mem,
copy run scp to start a file transfer to save the configuration on a
SCP host temporary directory.
The configuration files are then checked in into a GitLab repository so it’s
easy to track and compare configuration files.
To outline the idea, I made the drawing shown below.
Low Level functions to connect to devices with pexpect
Function for Cisco Switch (IOS)
Because of different CLI syntax, the devices (or type of device) need their own
function. For example the syntax for a Cisco switch (IOS) is different than the
syntax of a Cisco Wireless Controller (AirEOS).
I’m connecting always with a “secure channel” (SSH) to the devices.
pexpect is straight forward
(expect/sendline) so I am not going into the detail.
What I like to do is to set an exec banner with the date and the information
that a backup was done. After changing the banner it’s always a good idea
to save the configuration in case the administrator forgot it ;)
After the wr mem command the configuration file is copied with SCP
(Secure Copy) to the hosts tmp directory. In my case the script and the tmp
directory is on the virtual machine where my Netbox installation is running.
If something goes wrong (for example script cannot log in or switch is down) the
code is in a try/except block to handle errors.
Function for Cisco Wireless Controller
The same principle is valid for a Cisco Wireless Controller, however the CLI
syntax is different. Instead of the IOS commands, AirEOS ueses save config,
transfer upload. Please note that a file transfer with SCP is not possible,
therefore I’m using SFTP (Secure FTP) to have a secure communication channel.
Function for Cisco ASA Firewall
The Cisco ASA Firewall runs into a dialog when I use the scp command.
To handle this dialog, I am just sending a newline in the assumption that
the provided parameters are correct.
This is now the script output with the low level device functions.
As expected, the .cfg files are now waiting in the /tmp directory for the Gitlab
repo checkin function…