So you want to automate all the things in your network? Great! more and more enterprises are realizing the benefits of automating the network and are demanding more from their engineering staff. You’re also probably thinking about your career as well and how these automation skills will really come in handy to progress your career. Like I said, Network Automation skills are in high demand now.
So now what?
If you’re like me, you’ll jump straight into it and quickly realize that automating what can be considered the “life and blood” of an enterprise can be a daunting task. Rest assured though, there are things you can do today to begin your automation journey without needing to jump right into the deep end.
Standardize and Document
It would be remiss if I start off by saying that JC in his book “Automate Your Network” recommends starting your Automation Journey off by documenting and standardizing anything and everything in your network. For me, a big benefit of doing this before I dove into python and scripting was that I was able to bring my environment into a standard that makes building automation a very simple task.
I admit that it took me a bit of time and investment to bring my network into a working standard but once things were aligned it made the code I wrote that much more reusable.
Template all the Things!
If your like me, than you probably have a bunch of standard configuration commands stowed away in an Excel Document. You may not know it but one simple thing you can do as your start the automation journey is to convert those Excel Documents into clean (and reusable) code using the JINJA2 python library.
By templating your commands with JINJA2 you’ll immediately see the sky is the limit when it comes to where those commands can be run from. Whether you push those templates to another Python Library like pyATS / netmiko or simply document them for other team members, you’ll quickly see the benefits of “codifying” those CLI commands at an early stage.
Create Tooling for your Team
As a Senior Engineer, whenever I see a team member create a little tool or even a dashboard I get all jittery and excited. In my opinion, enabling your team is a selfless task that is often forgotten about. This is something I recommend you do (regardless of where you are along your automation journey) as it will get you working with other frameworks and you’ll be one step closer to a more automated and programmatic environment.
I already have working automation solutions and I think I can translate / refactor / at least be inspired by previous Ansible-based solutions.
Where to start?
I’ve been down the road of learning network automation from scratch – this time let’s start with simple information gathering and transformation.
Speaking of inspiration – I am going to start with a “Just the Facts” approach and go get – show interfaces status – my favourite command – into a CSV, MD, and this time let’s spice it up and also throw in an HTML page. From Genie parsed JSON.
Only this time using pure Python – no Ansible training wheels (crutches ?)
How to attack this ?
Break it down in human language and then see if we can translate it to Python is one approach. Another is to find working examples and guides provided by the Cisco team. Using a mix of the two and some other online resources here is how I did it.
The job folder is where I will keep the pyATS job file and and code file. Output will hold the 3 output files. I plan on hopefully using Jinja2 just like in Ansible so we need a Templates folder. Finally pyATS uses the concept of testbed files to setup connectivity and authentication. These are very similar to Ansible group_vars.
I’ve included a .gitignore file to keep the .pyc files out of the Git repository.
The Job file. This is a pyATS control file you can use to run the code. You can feed arguments in this way but I have not done that here.
The job file
Pretty simple so far – import the os and run the code.
First thing in the Python code is to setup the Python environment you need. Make sure to import JSON as we need to work with the Genie parsed data.
The actual code
Next we will setup Jinja2 and the File loader
Jinja2 setup
Now we import Genie and pyATS
Setup a logger
Ok so we need 3 source templates one for each file type
Turn on the logger
Let’s load up the testbed file
A testbed looks like this:
Note that yes! We CAN encrypt the string! %ENC{ } represents the pyATS encrypted string! Safe to store in Git repos!
Now some magic – we parse our command into a variable as JSON
Run the results thru the templates
While look like this:
CSVMarkdownHTML
Then we create the output files back in Python to finish the playbook
Which look like – ha! – we dont know if this works yet! Lets check it out!
The job in action
The command to run the job
Next it loads up the testbed
pyATS is very verbose but in a good verbose with valuable information about your job
Next the actual SSH connection sets up using Unicron (this is different than Ansible which uses paramiko)
Ok my device’s banner is displayed. My banner is left over from some CI/CD work but it’s the right banner – I’m in !
Some basic platform stuff gets dumped to the job log followed by my next job steps
It seems to be working so farshow interfaces status
Ok it’s fired the command! Milestone in the job reached – now it should register this result as JSON in a variable next.
Now during my development I added the following to confirm this step was working to dump the variable to the screen:
print {{ variable name }}
Print replaces debug: msg=”{{ }}” – good!
Similar to an Ansible recap we get a pyATS Easypy Report
Easypy Report > Ansible.log
The Git Add * test
I like to build suspense so I change directories up a folder and try to stage, hopefully, the 3 new files into Git
It means, seemingly, I’ve been mastering the wrong tool. That a faster, easier, and more elegant tool is available. This is ok – I feel like Ansible was primary school and I’m moving into the next stage of my life as a developer and moving up into high school with Python.
It also means I have a lot of code to refactor into Python – also fine – a good opportunity to teach my colleagues.
I also means I will be focusing less and less on Ansible I think and more and more on Python
20 years ago I was studying to become a computer programmer analyst in college writing C++, Java, Visual Basic 6, COBOL, CICS, JCL, HTML, CSS, SQL, and JavaScript and now, two decades later, I still have the magic touch and have figured out Python.
You can expect a lot more solutions like this – in fact I am going to see if I can work in my #chatbot / #voicebot capabilities into Python.
A modern approach to the Cisco IOS-XE show interfaces status command using Python pyATS / Genie and Jinja2 templating to create business-ready CSV, Markdown, and HTML files
This next post may seem like science fiction. I woke up this morning and checked that my output files – MP3 files – really did exist and that I actually made my Cisco network “talk” to me!
This post is right out of Star Trek so strap yourself in!
Can we make the network talk to us?
After my success with my #chatbot my brain decided to keep going further and further until I found myself thinking about how I could actually make this real. Like most problems let’s break it down and describe it. How much of this can I already achieve and what tools do I need to get the rest of the solution in place?
I know I can get network data back in the form of JSON (text) – so in theory all I need is a text-to-speech conversion tool.
Enter: Google Cloud !
That’s right Google Cloud offers exactly what I am looking for – a RESTful API that accepts text and returns “speech” ! With over 200 languages in both male and female voices I could even get this speech in French Canadian spoken in a dozen or so different voices!
I am getting ahead of myself but that is the vision:
Go get data, automatically, from the network (easy)
Convert to JSON (also easy)
Feed the JSON text to the Google Cloud API (in theory, also easy)
The process – Google Cloud setup
There is some Google Cloud overhead involved here and this service is “free” – for up to 1 million processed text words or 3 months whichever comes first. It also looks like you get $300 in Google bucks and only 3 months of free access to Google Cloud.
Credit card warning: You need a credit card to sign up for this. They assured me, multiple times, that this does not automatically roll over to a paid subscription after the trial expires you have to actually engage and click and accept a full registration. So I hope this turns out to be free for 3 months and no actual charges show up on my credit card. But in the name of science fiction I press on.
So go setup a Google Cloud account and then your first project and eventually you will land on a page that looks like this.
Enable an API and search for text
Enable this API and investigate the documentation and examples if you like.
Now Google Cloud APIs are very secure to the point of confusion. So I have not fully ironed out the whole automation pipeline yet – mainly because of how complex their OAuth2 requests seem to be – but for now I have a work around I will show you to at least achieve the theoretical goal. We can circle back and mess with the authentication later. (Agile)
Setup OAuth2 credentials (or a Service Account if you want to use a JSON file they provide you)
Make sure it is a Web Application
This will provide you your clientID and secret.
For most OAuth2 that’s all you need – maybe I am missing the correct OAuth2 token URL to request a token but for now there is another tool you can use to get a token.
Google has an OAuth2 Developer Playground you can use to get a token while we figure out the OAuth stuff in the background
Follow the steps to select the API you want to develop (Cloud Text-To-Speech)
Then in the next step you can request and receive a development token
You can also refresh this token / request a new token. So copy that Access Token we will need it for Postman / Ansible in the next steps.
Moving to Postman
Normally under my collection I would setup my OAuth – here is the screenshot of the settings I’m just not sure of. And here is the missing link to full automation.
So far so good here
Again, this might be something trivial and I am 99% sure its because I have not setup this redirection or linked the two things but it was getting late and I wanted to get this working and not get stuck in the OAuth2 weeds
First here is what I think I have right:
Token name: Google API Auth URL: https://accounts.google.com/o/oauth2/auth Access Token URL: https://accounts.google.com/o/oauth2/token Client ID: Client Secret: Scope: https://www.googleapis.com/auth/cloud-platform
But what I’m not really sure what to do with is this Callback URL – I don’t have one of those ?
Callback URL: This is my problem I am really not sure what I need to do here ?
I believe I need to add it here:
But I have no cookie crumbs to follow all of the ? help icons are sort of “This is where your Authorized redirect URLs go” and thats it ?
Open call to Google Cloud Development – I just need this last little step then the rest of this can be automated
Anyway moving along – pretending we have this OAuth2 working – we can cheat for now using the OAuth2 Playground method.
So here is the Postman request:
We want a new POST request in the Google Cloud API Postman Collection. The URL is:
So cheat (for now) and grab the token from the OAuth2 Playground and then in your Postman Request Authorization tab – select Bearer Token and paste in your token. From my experience this will likely start with ya29 (so you know you have the right data here to paste in)
Tab over to Headers and double-check you have Bearerya29.(your key here)
As far as the body goes – again we want RAW JSON
Now for the science fiction – in the body, in JSON, we setup what text we want to what speech
The canned example they provide
So we need the input (text) which is the text string we want converted.
We then select our voice – including the languageCode and name (and there are over 200 to choose from) – and the gender of the voice we want.
Lastly we want the audioConfig including the audioEncoding – and since MP3 was life for me in the mid to late 90s – let’s go with MP3 !
Hit Send and fire away!
Good start – a 200 OK with 52KB of data returned. It is returned as a JSON string:
Incredible stuff – this is the human voice pattern saying the text string – expressed as a base64-encoded audio string !
Ok – very cool stuff – but what am I supposed to do with it?
Fortunately Google Cloud has the insight we need
Hey – it’s exactly where we are at ! We have the audioContent and now we need to decode it!
Since I am still developing in my Windows world with Postman let’s decode our canned example
Carefully right-click copy (don’t actually click the link Postman will spawn a GET tab against the URL thinking you are trying to follow the URL along)
Now create a standard text (.txt) file in a C:\temp\decode folder and paste in the buffered response
I’ve highlighted the “audioContent”: “ – you have to strip this out / delete it as well as the last trailing “ at the end of the string – we just want the data starting with // and beyond to the end of the string
Lauch cmd and change to the C:\Temp\Decode folder and run the command
certutil -decode sample.txt sample.mp3
As you see if your text file was valid you should get a completed successfully response from the certutil utility. If not – check your string again for leading and trailing characters.
Otherwise – launch the file and have a listen!
How cool is that?!?!?
Enter: Network Automation
As I’ve said before anything I can make with with Postman I can automate with the Ansible URI module! But instead of some static text – I plan on getting network information back and having my network talk to me!
The playbook:
First we will prompt for credentials to authenticate
Now – let’s start with something relatively simple – can I “ask” the Core what IOS version it’s running? Sure – let’s go get the Ansible Facts, of which the IOS version is one of them, and pass the results along to the API !
For now we will hard code our token – again once I figure this out I will just have another previous Ansible URI step to go get my token with prompted ClientID / Client Secret at the start of the playbook along with the Cisco credentials. Again, temporary work around
Again because I have used body_format: json I can write the body in YAML.
Ok so for our body let’s have some fun and try an English (US) WaveNet-AMale.
For the actual text lets mix a static string “John the Lab Core is running version” and then the magic Ansible Facts variable {{ ansible_facts[‘net_version’] }}
And see if this works
We need to register the response from the Google Cloud API and delegate the task to the localhost:
So now we need to parse and get just the base64-audio string into a text file. Just like in Postman this is contained in the json.audioContent key:
Now we have to decode the file! But this time with a Linux utility not a Windows utility
We can call the shell from Ansible easily to do this task:
Now in theory this should all work and I should get a text file and an MP3 file. Let’s run the playbook!
Lets check if Git picked a new file!
Ok ! What does it sound like!?!
Ok this is incredible!
Let’s try some Genie / pyATS parsing and some different languages !
Copy and paste and rename the previous playbook and call the new file GoogleCloudTextToSpeech_Sh_Int_Status.yml
Replace the ios_facts task with the following tasks
So now for our actual API call we want to conditionally loop over each interface if is DOWN / DOWN (meaning not UP / UP and not administratively DOWN)
Now as an experiment – let’s use French – Canadian in a FemaleWavenet voice.
Does this also translatethe English text to French? Do do I need to write the text en francais? Lets try it!
So this whole task now looks like this:
Now we need another loop and another condition to register the text from the results. We loop over the results of the first loop and when there is audioContent send that content to the text file.
Caution! RegEx ahead! Don’t be alarmed! Because of the “slashes” in an interface (Gigabit10/0/5) the file path will get messed up so let’s regex them to underscores
Then we need to decode the text files!
So let’s run the playbook!
So far so good – now our conditionals should kick in – we should see some items skipped in light blue text then our match hits in green
Similarly, our next step should also have skipped items and then yellow text indicating the audioContent has been captured
Which is finally converted to audio
What does it sound like!??! Did it automatically translate the text as well as convert it to speech?
TenGig
Gig
A little more fun with languages
I won’t post all the code but I’ve had a lot of fun with this !
How about the total number of port-channels on the Core – in Japanese ?!
Summary
In my opinion this Google Cloud API and network automation integration could change everything! Imagine if you will:
Global, multilingual teams
Elimination of technical text -> Human constructed phrasing, context, and simplicity
Audio files in your source of truth
Integrated with #chatops and #chatbots
Visually impaired or otherwise physical challenges with text-based operations
A talking network!
This was a lot of fun and I hope you found it interesting! I would love to hear your feedback!
As you may know I love to play with new toys. I especially love connecting new toys with my old toys. What you may not know is that I am also an avid World of Warcraft fan and player! In order to run what are known as “raids”, group content designed for 10 – 30 players, I use a program called Discord.
My goal was simple – could I send myself messages in Discord from my Ansible playbooks with network state data? Could I create a #chatbot in this way ?
As it turns out not only could I achieve this – it is actually pretty straight forward and simple to do!
Setup
There are not a lot of steps in the setup.
Download and install Discord
Setup an account
Create a Server
Create a Channel
I named my channel AutomateYourNetwork and set it up as private with invite only RBAC to see the channel
Once we have a server and channel setup we need to setup the Integrations
Now setup a WebHook
Select the channel you want your chatbot to send messages to
We will need the Webhook URL
Postman Development
As with all new API development I always start in Postman to sort out the authentication, headers, and body to POST against this new Discord Webhook.
First let’s setup a new Postman Collection called Discord; add a new POST request to this collection
For the request itself make sure you change the default GET to a POST and then use the following URL:
https://discord./com/api/webhooks/< your URL copied from Discord here>
The body is flexible but to get started let’s just use a small set of values.
Set your body to RAW JSON
And add this body (change your username unless you want this message to look like it came from me!!)
Now if you really want to see how fast / real-time / amazingly cool this is – make sure you have your Discord logged in but minimized to your system tray
Hit SEND in Postman
Your Discord should have notified you about a new message! In my system tray the icon has also changed!
Which is no surprise because back in Postman we see we received a valid 204No Content response from the API
Lets see what Discord looks like
How cool is this?!?
Integrating with Network Automation and Infrastructure as Code
Ok this is great – but can we now integrate this into our CI/CD pipeline Ansible playbooks?
Can I send myself network state data ? Can we create a #chatops bot ?
Yes we can!
Lets start with Ansible Facts – and see if we can chat ourselves the current version of a device.
First let’s setup our credential prompts
Then, let’s use ios_facts
Thats more or less all I need to do – next let’s use the URI module to send ourselves a chat!
I will break down this next URI task; first setup the URL – again after /webhooks/ {{your URL here }}
This is a POST
I like to do this next step for two reasons; one to set the body of the POST to JSON (obvious) but also to allow me to use YAML syntax in Ansible to write the body of the POST (not so obvious). Without this my body would need the JSON formatting (think moustaches and brackets) which is hard enough to write on it’s own, and very hard to write inside a YAML Ansible task
Meaning I can format the body as such (in YAML):
And, like we saw in Postman, we are expecting a 204 back and no content
Make sure you are delegating to the localhost (you dont want this step to run on your Cisco switch)
Again back to the body we are accessing the Ansible magic variable ansible_facts and the key net_version
Lets run the playbook!
Discord looks happy
And, with the power of Internet Magic, here is our message!
This is incredible – let me integrate Cisco Genie / pyATS now and send some parsed network state data next – to show the real power here
The playbook structure is more or less the same so save the Ansible Facts version playbook and copy / rename it to Show Int Status.
Keep the prompts; remove the ios_facts task and replace it with this task
Followed by the Genie parsing step
Then we need to adjust the Discord message – for my example I only want a message if, for example, an interface is configured to be UP / UP (meaning it is not administratively down) but is DOWN / DOWN (notconnected state). I don’t care about UP/UP or Administratively Down interfaces.
Again, I will break down this
Most of this is the same
Here comes my magic with Genie. We want to loop over each interface Genie has parsed into the registered variable pyatsint_status_raw.interfaces. We need to convert this dictionary into a list of items so filter it | dict2items
Now we want a condition on this loop; only call the Discord API when the {{ item.value.status }} key (that is to say each iteration in the loops status value) when it equals “notconnect“
Now we can reference the item.value for the per-interface name and the item.value.status for the notconnect status when it hits a match in the body of the message we are sending to Discord.
The task as a whole looks like this:
So we run this new playbook which sort of looks like this. Remember we have a condition so the light blue text indicates non-matches / skipped interfaces (because they are connected or admin down); green indicates a hit.
Drumroll please
And now in Discord I have this wonderful, pager-like, real-time “alert”
Now go build one!
Here is the GitHub repository – go try to build one for your network!
Ansible playbooks that chat with Discord using Ansible, Genie/pyATS, and the Discord webhooks that send network state information as a Discord message!
The security of my network keeps me up at night. Honestly it does. We live in a world where enterprise networks are defending themselves against state-sponsored attacks. But what do attackers look for? Typically, open, well-known, vulnerabilities.
Well, at least to the hackers, attackers, and even script-kiddies, these vulnerabilities are well-known. Those playing defense are often a step or two behind just identifying vulnerabilities – and often times at the mercy of patch-management cycles or operational constraints that prevent them of addressing (patching) these waiting-to-be-exploited holes in the network.
What can we do about it?
The first thing we can do is to stay informed ! But this alone can be a difficult task with a fleet of various platforms running various software versions at scale. How many flavours of Cisco IOS, IOS-XE, and NXOS platforms make up your enterprise? What version are they running? And most importantly is that version compromised?
The old way might be to get e-mail notifications (hurray more e-mail!), maybe RSS-feeds, or go device-by-device, webpage-by-webpage, looking up the version and if it’s open to attack or not.
Do you see why, now, how an enterprise becomes vulnerable? It’s tedious and time-intensive work. And the moment you are done – the data is stale – what, are you going to wake up every day and review threats like this manually? Assign staff to do this? Just accept the risk and do they best you can trying to patch quarterly ?
Enter: Automation
These types of tasks beg to be solved with automation !
So how can you do it?
Let’s just lay out a high level, human language, defined use-case / wish list.
Can we, at scale, go get the current IOS / IOS-XE / NXOS software version from a device?
Then can we send that particular version somewhere to find out if it has been compromised ?
Can we generate a report from the data above?
Technically the above is all feasible; easy even!
Yes, we can use Ansible and the Cisco Genie Parser to capture the current software version
As with any new REST API I like to start with Postman and then transform working requests into Ansible playbooks.
First, under a new or existing Cisco.com Collection, add a new request called IOS Vulnerabilities
Cisco.com uses OAuth2 authentication mechanism where you first must authenticate against one REST API (https://cloudsso.cisco.com/as/token.oauth2) which provides back authorization Bearer token used to then authenticate and authorize against subsequent Cisco.com APIs
Your Client ID and Secret are found in the API portal after you register the OpenVuln API
Let’s hard code a version and see what flaws it has
Ok so it has at least 1 open vulnerability!
Does it tell us what version fixes it?
Ok let’s check that version quickly while we are still in Postman
This version has no disclosed vulnerabilities!
One interesting thing of note – and our automation is going to need to handle it – is that if there are no flaws found we get a 404 back from the API not a 200 like our flawed response!
The Playbook
For the sake of the example I am using prompted inputs / response but these variables could easily be hardcoded and Ansible Vaulted.
So first prompt for your Cisco hosts username and password and your Cisco.com ClientID and Client Secret
Register the response
Then in the IOS.yml group_vars I have my Ansible network connections
I’ve put all IOS-platforms in this group in the hosts file to target them
Next step run the show version ios_command and register the reponse
Genie parse and register the JSON
Now we need, just like in Postman, to go get the OAuth2 token but instead of Postman we need to use the Ansible URI module
Then we have to parse this response and setup our Bearer and Token components from the response JSON.
Now that we have our token we can authenticate against the IOS open Vulernability API
There are a couple of things going on here:
We are passing the Genie parsed .version.version key to the API for each IOS host in our list
We are using the {{ token_type }} and {{ access_token }} to Authorize
We have to expect two different status codes; 200 (flaws found on a host) and 404 (no flaws for the host software version)
I’ve added until and delay to slow down / throttle the API requests as not to get a 406 back because I’ve overwhelmed the 10 requests per second upper limit
We register the JSON response from the API
As always I like to create a “nice” (easy to read) version of the output in a .json file
Note we need to Loop over each host in our playbook (using the Ansible magic variable ansible_play_hosts) so the JSON file has a data set for each host in the playbook.
Lastly we run the template module to pass the data into Jinja2 where we will create a business-ready CSV file
Which looks like this broken apart:
Like building the JSON file first we need to loop over the hosts in the playbook.
Then we check if the errorCode is defined. You could also look at the 404 status code here. Either way if you get the error it means there are no vulnerabilities.
So add a row of data with the hostname, “N/A” for most fields, and the json.errorMessage from the API (or just hardcode “No flaws” or whatever you want here; “compliant”)
Now if the errorCode is not defined it means there are open flaws and we will get back other data we need to loop into.
I am choosing to do a nested set of two loops – one for each advisory in the list of advisories per software version. Then inside that loop another loop, adding a row of data to the spreadsheet, for each BugID found as well (which is also a list).
There are a few more lists like CVEs for example – you can either loop of these as well (but we start to get into too much repetition / rows of data) – or just use regex_replace(‘,’,’ ‘) to remove all commas inside a field. The result is the list spaced out inside the cell sorted alphabetically but if you do not do this it will throw off the number of cells in your CSV
The results
What can you do with “just” a CSV file?
With Excel or simply VS Code with the Excel Preview extension – some pretty awesome things!
I can, for example, pick the ID field and filter down a particular flaw in the list – which would then provide me all the hosts affected by that bug
Or pick a host out of the list and see what flaws it has, if any. Or any of the columns we have setup in the Jinja2
Included in the report is also the SEVERITY and BASE SCORE for quick decision making or the Detailed Publication URL to get a detailed report for closer analysis.
I have a lot of new followers and people looking for materials on Network Automation @VMware published this amazing – and free and digitial – "For Dummies" guide https://t.co/PnSDGktZ6w
My good buddy Zig – who hosted me on Zigbits podcast for a 2-part Network Design (Part One) and Network Automation (Part Two – coming in February) discussion.
Here you can easily start capturing Ansible Facts for IOS and NXOS and transform the JSON into CSV and Markdown !
Also included are a bunch of valuable Genie parsed show commands which transform the response into JSON then again transforms the JSON into CSV and Markdown!
The playbooks use Prompts so you should be able to clone the repo and update the hosts file and start targeting your hosts! For full enterprise support I suggest you refactor the group_vars and remove the prompts moving to full Ansible Vault – but for portability and ease of start-up I’ve made them prompted playbooks for now.
I would love to hear how they work out for you – please comment below if you have success!
This major revision basically shifts away from lineinfile to Jinaj2 Templates for scale, performance, readability, and general best practices.
Serial 2 Info
The Cisco Serial 2 Info API receives a valid serial number and then returns structured JSON with your Cisco Contractual information !
The playbook uses the Genie parser to parse the show inventory command
After authenticating against the OAuth 2 service to get a Bearer token
It provides the API the serial number for every part per device.
The API provides the following information back:
Which we first dump into JSON and YAML files
Then template into CSV and MD
Using Jinja2
Which gives us:
Recommended Release
The other, very similar, Ansible playbook uses the Cisco Recommended Release API to create a spreadsheet with the current image on a host and the Cisco recommended version for that host given the Part ID (PID)
Here we don’t even have to use Genie to parse we can use the Ansible Facts module
And we transform again with Jinja2
And get this create report!
Please reach out to me directly if you need any help implementing these playbooks but I believe the instructions and code to be easy enough any beginner, with a little bit of refactoring and thought, could use this code as a starting point in their automation journey.
Ansible playbooks that capture serial number and PID and send them to the Cisco.com APIs transforming the response into business-ready documents. Version 2.0 uses Jinja2 templates.
One of my favourite recipes is the Hakuna Frittata both because not only am I a big fan of puns, I also enjoy this hearty vegetarian meal that even I can handle putting together.
Inspired by this simple recipe I have decided to try and document my highly successful Ansible Cisco NXOS Facts playbook that captures and transforms raw facts from the data centre into business-ready documentation – automatically.
Ansible Cisco NXOS Facts to Business-Ready Documentation Prep: 60-90 Min Cook: 2-3 Min Serves: An entire enterprise
Ingredients
1 Preheated Visual Studio Code 1 Git repository and Git 1 stick of Linux (a host with Ansible installed and SSH connectivity to the network devices) 3 pinches of Python filters 1 Cup of Ansible playbook (a YAML file with the serially executed tasks Ansible will perform) 1 Cup of Ansible module – NXOS_Facts 2 Tablespoons of Jinja2 Template 1 Teaspoon of hosts file 1 Tablespoon of group_vars 2 Raw Eggs – Cisco NXOS 7000 Aggregation Switches
Helpful Tip
This is not magic but did not necessarily come easy to me. You can use debug and print msg to yourself at the CLI. At each step that I register or have data inside a new variable I like to print it to the screen (one to see what the data, in JSON format, looks like; and two, to confirm my variable is not empty!)
Directions
1. You will need to first setup a hosts file listing your targeted hosts. I like to have a hierarchy as such:
hosts [DC:children] DCAgg DCAccess
[DCAgg] N7K01 N7K02
[DCAccess] N5KA01 N5KB01 N5KA02 N5KB02
Or whatever your logical topology resembles.
2. Next we need to be able to securely connect to the devices. Create a group_vars folder and inside create a file that matches your hosts group name – in this case DC.yml
DC.yml +
3. Create all the various output folder structure you require to store the files the playbook creates. I like something hierarchical again:
4. Create a playbooks folder to store the YAML file format Ansible playbook and a file called CiscoDCAggFacts.yml
In this playbook, which runs serially, we first capture the facts then transform them into business-ready documentation.
First we scope our targeted hosts (hosts: DCAgg)
Then we use the NXOS_Facts module to go gather all of the data. I want all the data so I choose gather_subset : – all but I could pick a smaller subset of facts to collect.
Next, and this is an important step, we take the captured data, now stored in the magic Ansible variable – {{ ansible_facts }} and put that into output files.
Using the | to_nice_json and | to_nice_yamlPython filters we can make the “RAW JSON” inside the variable (one long string if you were to look at it) into human-readable documentation.
4b. Repeatable step
NXOS Facts provides facts that can be put into the following distinct reports:
Platform information (hostname, serial number, license, software version, disk and memory information) A list of all of the installed Modules hosted on the platform A list of all IP addresses hosted on the platform A list of all VLANs hosted on the platform A list of all of the enabled Features on the platform A list of all of the Interfaces, physical and virtual, including Fabric Extenders (FEX) A list of all connected Neighbors Fan information Power Supply information
For some of these files, if the JSON data is structured in way that lends itself, I will create both a Comma-Separated Values (csv; a spreadsheet) file and a markdown (md; “html-light”) file. Some of the reports is just the csv file (IPs, Features, VLANs specifically).
The follow code can be copied 9 times and adjusted by updating the references – the task name, the template name, and the output file name – otherwise the basic structure is repeatable.
In order to create the HTML mind map you will also need mark map installed.
Another example of the code – this is the Interfaces section – notice only the name, src, and dest file names need to be updated as well as the MD and HTML file names in the shell command.
5. The Jinja2 Templates
Now that we have finished our Ansible playbook we need to create the Jinja2 templates we reference in the Ansible template module (in the src line)
Create the following folder structure to store the templates:
roles\dc\dc_agg\templates
Then, for each of the 9 templating tasks, create a matching .j2 file – for example the “base facts” as I like to call them – CiscoDCAggFacts.j2
In this template we need an If Else End If structure to test if we are templating csv or markdown then some For Loops to iterate over the JSON lists and key value pairs.
Add a header row with columns for the various fields of data. Reference your Nice JSON file to find the key value pairs.
No “For Loop” is required here just straight data from the JSON
Since its not csv it must be md; so add the appropriate markdown header rows
Then add the data row using markdown pipes for delimiters instead of commas
Close out the If
An example with For Loops might be Interfaces or Neighbors but the rest of the syntax and structure is the same
Now because there are multiple interfaces I need to loop or iterate over each interface.
Now add the row of data
Note you can include “In-line” If statements to check if a variable is defined. Some interfaces might not have a Description for example. Test if it is defined first, and if not (else) use a default of “No Description”
Other fields are imperative and do not need to be tested.
Close the Loop
Now do the markdown headers for Interfaces
Then the For Loop again and data row again but using pipes
Then close out the If statement
Complete the remaining templates. Save everything and Git commit / push up to your repo.
Cooking Time
Lets run the playbook against two fully-loaded production Nexus 7000s using the Linux time command
Two minutes in the oven !
Results
Some samples of the output.
First the Nice JSON – note the lists have been collapsed to be brief but any of the lists can be expanded in VS Code for the details
Interfaces
Neighbors
Now some prefer YAML to JSON so we have the exact same data but in YAML format as well
Now the above is already incredible but I wouldn’t call JSON and YAML files “business-ready” – for that we need a spreadsheet!
The real tasty stuff are the CSV files!
The general facts
Interfaces
Note that you can filter these csv files directly in VS Code – here I have applied a filter on all interfaces without a description
This captures all types of interfaces
Including SVIs
The Markdown provides a quickly rendered VS Code or browser experience
And the Interactive HTML is pretty neat!
Now remember we have all of these file types for all of the various facts these are just a few samples I like to hand out to the audience – for the full blown experience you can hopefully follow this recipe and cook your own Cisco NXOS Ansible Facts playbook!
Please reach out if you need any additional tips or advice ! I can be reached here or on my social media platforms.
