Kirk Byers Python for Network Engineers Videos

Over the last three months I’ve been transitioning back over to network engineering. When I first started working in IT, my role was as a network technician, but slowly I took on more and more systems administration and engineering, and the work I was doing was mostly with PowerShell.

As a result, my Python skills have atrophied over the years since I was so focused on PowerShell, and if there’s one thing I’ve learned while being put in charge of managing thousands of switches, it’s that I need some scripting in place to handle mass changes.

 

Python Logo

The perfect class to get myself back in the Python game was from reddit, offered by Kirk Byers called “Python for Network Engineers“. It’s a introductory course on some Python basics, which for offered enough to get me going again.

I’m putting this list of the videos online for myself since I hate referencing my emails all the time, but if someone else finds it useful, awesome.

Lesson 1: Why Python, the Shell, and Strings
Lesson 2: Numbers, Files, Lists, and Linters
Lesson 3: Conditionals and Loops
Lesson 4: Dictionaries, Exceptions, and Regular Expressions
Lesson 5: Functions and the Python Debugger
Lesson 6: Netmiko
Lesson 7: Jinja2, YAML and JSON
Lesson 8: Libraries, PIP, and Virtual Environments

Lesson 1: Why Python, the Shell, and Strings

  1. Introduction 
    Video https://vimeo.com/243034300
    Length is 7 minutes
  2. Why Learn Programing?
    Video https://vimeo.com/243905715
    Length is 1 minute
  3. Why Python?
    Video https://vimeo.com/243909371
    Length is 3 minutes
  4. Python2 versus Python3
    Video https://vimeo.com/243912631
    Length is 2 minutes
  5. Characteristics of Python
    Video https://vimeo.com/243918300
    Length is 5 minutes
  6. The Python Interpreter Shell
    Video https://vimeo.com/242411259
    Length is 9 minutes
  7. IPython
    Video https://vimeo.com/242460561
    Length is 4 minutes
  8. Printing to stdout and Reading from stdin
    Video https://vimeo.com/243028886
    Length is 6 minutes
  9. Dir, Help, and Variables
    Video https://vimeo.com/243480156
    Length is 10 minutes
  10. Python Strings (Part 1)
    Video https://vimeo.com/243481392
    Length is 6 minutes
  11. Python Strings (Part 2)
    Video https://vimeo.com/243482081
    Length is 8 minutes
  12. Python Strings (Part 3)
    Video https://vimeo.com/243482871
    Length is 10 minutes
  13. Python String Formatting (Part 1)
    Video https://vimeo.com/243936489
    Length is 12 minutes
  14. Python String Formatting (Part 2)
    Video https://vimeo.com/243956669
    Length is 4 minutes

Lesson 2: Numbers, Files, Lists, and Linters

  1. Numbers
    Video https://vimeo.com/244128549
    Length is 9 minutes
  2. Files
    Video https://vimeo.com/244127459
    Length is 10 minutes
  3. Lists
    Video https://vimeo.com/244257596
    Length is 6 minutes
  4. List Slices
    Video https://vimeo.com/244259492
    Length is 4 minutes
  5. Lists are Mutable
    Video https://vimeo.com/244287000
    Length is 5 minutes
  6. Tuples
    Video https://vimeo.com/244153105
    Length is 3 minutes
  7. Using .join()
    ​Video https://vimeo.com/245464488
    Length is 3 minutes
  8. sys.argv
    Video https://vimeo.com/245464766
    Length is 2 minutes
  9. Linters
    Video https://vimeo.com/245102246
    Length is 6 minutes

Lesson 3: Conditionals and Loops

  1. Conditionals
    Video https://vimeo.com/245104620
    Length is 8 minutes
  2. Boolean Logic (Booleans, Ternary Operator, None)
    Video https://vimeo.com/245112558
    Length is 8 minutes
  3. Python For Loops
    Video https://vimeo.com/245466297
    Length is 5 minutes
  4. For Loops (Enumerate)
    Video https://vimeo.com/245477015
    Length is 6 minutes
  5. For Loops (Break and Continue)
    Video https://vimeo.com/245478016
    Length is 9 minutes
  6. While Loops
    Video https://vimeo.com/245545155
    Length is 5 minutes
  7. Loops Miscellaneous
    Video https://vimeo.com/245552604
    Length is 6 minutes

Lesson 4: Dictionaries, Exceptions, and Regular Expressions

  1. Dictionaries
    Video https://vimeo.com/246157566
    Length is 6 minutes
  2. Dictionaries Methods
    Video https://vimeo.com/246163031
    Length is 7 minutes
  3. Sets
    Video https://vimeo.com/246167477
    Length is 9 minutes
  4. Exceptions
    Video https://vimeo.com/246174686
    Length is 15 minutes
  5. Regular Expressions (Part1)
    Video https://vimeo.com/246184715
    Length is 15 minutes
  6. Regular Expressions (Part2)
    Video https://vimeo.com/246532117
    Length is 7 minutes
  7. Regular Expressions (Part3)
    Video https://vimeo.com/246534450
    Length is 8 minutes
  8. Regular Expressions, Other Methods
    Video https://vimeo.com/246535038
    Length is 4 minutes

Lesson 5: Functions and the Python Debugger

  1. Functions (Part1)
    Video link https://vimeo.com/247570174
    Length is 8 minute
  2. Functions (Part2)
    Video link https://vimeo.com/247581011
    Length is 11 minutes
  3. Misc Topics (Part1)
    Video link https://vimeo.com/247582360
    Length is 10 minutes
  4. Misc Topics (Part2)
    Video link https://vimeo.com/247655574
    Length is 8 minutes
  5. Python Debugger (pdb)
    Video link https://vimeo.com/247724017
    Length is 10 minutes

Lesson 6: Netmiko

  1. Netmiko Introduction and Basics 
    Video link https://vimeo.com/254569911
    Length is 8 minutes
  2. Netmiko Show Commands
    Video link https://vimeo.com/254578980
    Length is 13 minutes
  3. Netmiko and Prompting
    Video link https://vimeo.com/254587832
    Length is 12 minutes
  4. Netmiko and TextFSM
    Video link https://vimeo.com/254611876
    Length is 10 minutes
  5. Netmiko Config Changes
    Video link https://vimeo.com/254614073
    Length is 8 minutes
  6. Netmiko Troubleshooting
    Video link https://vimeo.com/254786724
    Length is 9 minutes

Lesson 7: Jinja2, YAML and JSON

  1. Jinja2 Basics
    Video link https://vimeo.com/257997257
    Length is 7 minutes
  2. Jinja2 For-Loops and Conditionals
    Video link https://vimeo.com/257999160
    Length is 9 minute
  3. Jinja2 and CSV
    Video link https://vimeo.com/258142987
    Length is 5 minutes
  4. Jinja2 Dictionaries and Nested Loops
    Video link https://vimeo.com/258145504
    Length is 11 minutes
  5. YAML Basics
    Video link https://vimeo.com/258161182
    Length is 9 minutes
  6. YAML Part2
    Video link https://vimeo.com/258169427
    Length is 10 minutes
  7. Using Python to Write YAML
    Video link https://vimeo.com/258171559
    Length is 3 minutes
  8. JSON
    Video link https://vimeo.com/258178243
    Length is 5 minutes
  9. Managing Data Structures
    Video link https://vimeo.com/258181273
    Length is 5 minutes

Lesson 8: Libraries, PIP, and Virtual Environments

  1. Importing Libraries
    Video link https://vimeo.com/259422351
    Length is 5 minutes
  2. sys.path and PYTHONPATH
    Video link https://vimeo.com/259423316
    Length is 7 minutes
  3. pip
    Video link https://vimeo.com/259424573
    Length is 7 minutes
  4. Virtual Environments
    Video link https://vimeo.com/259426537
    Length is 6 minutes
  5. Creating a Simple Python Module
    Video link https://vimeo.com/259427586
    Length is 4 minutes

Quickie: PXE 0xC0000001 Error in SCCM

When you’re imaging/PXE-booting in SCCM, I think the “0xC0000001” error is one of the strangest errors to troubleshoot, because the source of the error is related to some problem/conflict between TFTP and the network adapter of the machine you’re imaging — but then sometimes it has to do with the network adapter of your distribution point.

Windows Boot Manager Error 0xC0000001

I have encountered multiple solutions to this problem, and here are some of them from other blogs:

There are others.

However for me, I had the following scenario, and my solution turned out to be quite simple.

Context:

  • Trying to image Pentium-based, 4 GB HP ProBook x360 11 G1 EE laptops
  • From a VMWare DP, the machines receive the boot image just fine.
  • From a Hyper-V DP, ‘0xC0000001’ error occurs on these laptops.
    • For the sake of curiosity, I did the three items above (change reg key, changed network adapter properties, and even reinstalled WDS). None of these worked.
    • I reverted all those settings and put the DP back in a ‘vanilla’ state

I found this behavior to be really odd. Why would it download the boot image on one just fine, but not on the other? Perhaps the boot image needs network adapter?

Well, it turns out the solution for this model laptop was to add the network adapter driver* to the boot image. We generally don’t add network drivers to boot images unless necessary, which in this case it turned out it was.

And that was that. If you don’t know how to add drivers to the boot image, I’m not going to reinvent the wheel, but I will direct you to this website that has a decent how-to.

Happy SCCM-ing!

(Edit 20180710 – clarified the use of a driver)

(Edit 20190702 – Added Windows Updates as a potential cause).

Quick Thoughts: KVM Host Validation FUSE Failure – virt-host-validate

Here’s a quickie fix.

Was doing a fresh KVM install on CentOS 7, and tried to validate the install with running “virt-host-validate”, but I was getting one item failing and couldn’t find a fix. The error:

LXC: Checking if device /sys/fs/fuse/connections exists : FAIL (Load the ‘fuse’ module to enable /proc/ overrides)

LXC: Checking if device /sys/fs/fuse/connections exists : FAIL (Load the 'fuse' module to enable /proc/ overrides)

The fix: just reinstall FUSE:

Problem solved: LXC: Checking if device /sys/fs/fuse/connections exists : PASS

SCCM: Using 7-Zip to Deploy Large Packages/Applications

One PITA problem to deal in SCCM with when deploying large application installs like AutoDesk Inventor or Adobe Creative Cloud is the sheer size of the install, which can be 10-20 GBs in size. Well after a fellow Twitterer asked about zipping packages and so forth for deploying large packages and applications in SCCM, I responded with something I do at my organization, and thought I’d share the info. This probably isn’t really anything new, but it’s what I’ve done to solve the problem.

Gizmo from Gremlins
I couldn’t think of an image for this post, so you get Gizmo.

Deploying large packages over the network can take awhile; one solution to this is to compress the contents into a package/application, deploy the compressed contents with the 7-zip executable (and dll), then use the 7-zip .exe to uncompress the contents on the remote device. After the install is complete, just remove the uncompressed contents, and Bob’s your uncle.

This requires the 7z.exe and 7z.dll files, and of course the compressed package in whatever format you want (I prefer .7z).

Below is a batch file I use to perform this task, and I’m using AutoDesk Inventor 2017 as an example. I also have a Github page that has the complete install and uninstall for AutoDesk Inventor.