Automating your NMS build – Part 4 Adding Custom Views

This is part four in a series of using python and the RESTful API to automate the configuration of the HP IMC network management station.  Like with all things, it’s easier to learn something when you’re able to find a good reason to use those skills. I decided to extend my python skills by figuring out how to use python to configure my NMS using the RESTful API. 

If you’re interested, check out the other posts in this series

Creating Operators

Adding Devices

Changing Device Categories

Adding Custom Views

In this post, we’re going to use the RESTful API to programatically add a custom view, and then add devices to that custom view.  For those of you who don’t know, a custom view is simply a logical grouping of devices.  In IMC custom views also form the basis of the topology maps. In fact, a custom view and a topology map are essentially the same object internally,  The difference is just whether you chose to look at it as a list of devices in the normal interface or chose to look at it in the typical topology/visio format which we all know and might-not-love. 

Why might we want to add a custom view programatically you ask? While, the answer to that might be simply that we’re lazy and it’s easier and faster.  Or it might be that you don’t want to have to look through all the different devices, or, as in my case, that you simply want an excuse to extend your python skills.  Whatever you’re reasons are, custom views are something that just don’t get used enough in my opinion. 

Custom views are a great way to be able to zoom in on the status of a specific branch, a geographic area, maybe a logical grouping of devices that support a specific application?  It really doesn’t matter and the best part is that a single device can exist in multiple custom views at the same time, so there’s really no limit to how you put these views together. It all depends on what makes sense to you. 

 

The Code

This code is a little bit more complicated than some of the other examples we’ve looked at. We’re actually going to be using multiple functions together, but the logic should be pretty easy to follow.  I’m sure there are better ways to do this, but this seems to work for me.  I’m sure I’ll be back here in a year going “Why did I write it that way!?!?!?!?!?” but for now, I hope it’s simple enough for someone else to follow and possibly get inspired. 

The main function is really just calling the other functions which we will break down below

Step 1 – Create the Custom View

In this code, we’re going to simply use this small function that I created to gather the name of the custom view ( the view_name variable ) and then use that to create the JSON payload ( the payload variable ).  The other part of the JSON payload is the autoAddDevType variable which is hard-coded to 0.  This could be used to have the system automatically add new devices of a given type, but I”m in interested in doing the automation myself here. The last part of this code will be used as the input for another function, which is the return of the view name.  You can see in the main  function in the the view_name = create_new_view() line. 

Step 2 – Get Custom Views

For the next part, we are going to need to figure out what Id was assigned to this new view, to do this we’re going to have to go through a couple of steps. The first one is to ask the NMS to send us a list of all the known custom views. The following function will request the list, which will be returned as a JSON array, and then convert it over into a python list of dictionaries so we can work with it natively as a python object. You can see this in the main function in the  view_list = get_custom_views() line

Now that we have the view_list which is the list of all the views, we’re going to have to find the ID for the new view that we just created.  We do that by by using the get_view_id() function using the view_name as the input.  Essentially, this will look through each of the views in the view_list that was returned above and let us know when the ‘name’ value is equal to the view_name value that we captured above. Once it’s equal, we then return the ‘symbolId’ which is the internal unique numeric value assigned to this particular custom view. This is the number we’re going to use to identify the view that  that we want to add devices to.  Make sense? Now that we’ve got this number, we’re going to assign it to the object view_id for use later on. 

Note: I actually could have added the devices directly to the view in the original add_custom_view code code above, but then I’d have to write the modify function later if I ever wanted to change or add new devices to the view. I’m trying to follow the DRY ( Don’t Repeat Yourself ) advice here so I just write the modify here and I can then leverage it later without having to re-write the code.  

Step 3 – Generate the Device List

We’re not going to spend too much time on this part as I’m essentially re-using the code from the Changing Device Categories blog.  It’s pretty straight forward. I’m using some user-put to gather a list of devices that we want to add to this specific view and then capture it in the dev_list object.  What’s cool about doing it this way is that the returned list will search through all the IP addresses assigned to your devices, not just the managed address which might come up in the NMS interface where you would normally perform this step. There are ways around that as well, but that’s another blog. 

Step 4 – Add Devices to Existing Custom View

This last step is where things come together. We’re going to run the add_device_to_view(dev_list, view_id) function which is using the dev_list generated in step 3 and the view_id that we captured at the end of step 2 as the inputs.  Essentially, we’re just saying here  “ add all the devices I want to the view I just created “. 

Wrapping it Up

So this is just an example of how you can tie a few pieces of code together to help automate something that might otherwise take you a lot of manual labour. In this case, just a bunch of mouse clicks and depending on the fact that you were able to manually identify all the devices you wanted to add to a specific view.  Personally, I’d rather leave the hard work to the computers and move on to something that requires my brain.

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Automating your NMS build – Part 3 Changing Device Categories

In the first couple of posts in this series, we created some operators, then we added some devices.   In this post we’re going to look at something a little more complicated. In this post, we’re going to link a couple of different python functions together to meet the requirement which is to change a device from one category to another.

A bit about Device Categories

For those of you haven’t used HP’s Intelligent Management Centre before, the system automatically categorizes any discovered device, usually based upon SNMP sysobjectid. What this means is that when you run an auto discovery, the majority of your infrastructure will be properly classified right out of the box.

Screen Shot 2015 07 07 at 11 11 51 PM

This works great for devices which are SNMP enabled, as well as some other devices like ESX machines ( Virtual Devices ) which use SOAP as the management protocol, but it fails pretty miserably when dealing with devices which don’t support anything more than PING.  IMC’s default behaviour is to put anything which doesn’t respond to SNMP in the Desktop Category.

IP Phones aren’t smart

I’ve had customers who decided to discover all of their expensive IP phones and suddenly found out that none of them were classified properly. The problem with IP phones is that they are usually pretty stupid devices. Low memory, weak CPUs. Most of the processing/thinking is done by the PBX. I’ve never seen an IP phone that supports SNMP.

In this case we have two choices

  1. Manually change each IP phone from the Desktop category into the Voice category one device at a time.
  2. Use the RESTful API and a bit of code to do it wihile we go have a coffee

Filtering First

So the first thing we need to do is to identify the IP phones from the rest of the devices in the Desktop category. Thankfully, this is where having a well designed network can come in REALLY handy. Most Voice networks are designed so that the IP phones are automatically put into a voice vlan. This means that all phones SHOULD be in the same layer 3 network range.

The first piece of code we need to write is a simple piece of code which will allow the user to identify which of the categories they want to filter by. Although this might sound strange, we actually need to make sure that we only grab the DESKTOP devices in a specific subnet range. Imagine if you accidentally move the router or switch for this subnet into the voice category too. Really sucks leaving when you lose your router, right?

In this piece of code, we’re simply creating a dictionary which creates the link between the categoryId, which is the number IMC internally uses to identify the defined categories and the labels we humans use to identify them.  In a nutshell, this simply prints out the available categories.  Why you ask? Because the human running this script needs to known which categories they want to filter by.

This next performs two different functions

  1. Filters all known devices by the categories listed above
  2. Filters all known devices by an IP range.

Combining the two of them we’re able to easily fine all of the devices that have been classified in the Desktop Category in the L3 subnet of the IP phones and return that as a dictionary which contains, among other things, the device IDs which we’ll need in the next step.

Putting it all together

So the last piece of code is where the magic actually happens.

First we assign the output of the filtering function above into the variable called dev_list.  Essentially, this is a list of devices which meet the search criteria of the filtering function.

In our case, this means the list will consists of all the IP phones in the specific subnet that we filtered.

From there, we use the items in dev_list as input into a for loop which changes them into the new category.  ( see how we use the same print_category function from above? )

Wrapping it up

Hopefully this is a fairly useful example of how putting a few basic python functions together can help to substantially cut down on the amount of time it takes to perform what’s really a simple task. That’s the whole point of automation right?

As I continue learning, I can already see there a bunch of ways to improve this code, but hopefully having a simple working example will help people who are a couple of steps behind me on this journey take another step forward.

If you’re ahead of me on this journey and have suggestions, please feel free to comment!

@netmanchris