Lab 1: Using a declarative approach to network provisioning#

As you may have figured out by now, Kubernetes (K8s) was our guiding light in building a truly declarative automation platform — so in this lab, we'll use K8s and its tools to explore what this means.

You're probably wondering, "Why on earth should I venture into the world of Kubernetes (aka K8s) to manage my data center infrastructure, like my fabric?"

Well, the good news is that you don't need to — but that doesn't mean you shouldn't! With EDA, there is absolutely no requirement to know how to manage Custom Resources or even use K8s at all. You can use our UI or even our REST API if you're feeling adventurous. However, as you modernize your network automation toolchain, you may find that the success of K8s has brought a large number of community and enterprise integrations/tools, which you might find useful. And hey, you may even end up speaking the same language as your application folks, if that's of any interest, of course.

Let's take a look at what it may look like to use K8s and some of its tools to deploy a fabric.

Step 1: Creating a Fabric using Kubectl#

SSH into your assigned lab environment if you haven't already (you don't need EDA UI just yet):

Kubectl is the de facto CLI tool for all things K8s. It can be used to interact with a cluster and its resources.

Here is the K8s Custom Resource in the YAML format for deploying the configuration needed to create a functional fabric. This is our desired intent!

cat << 'EOF' | tee my-fabric.yaml | kubectl apply -f -
apiVersion: fabrics.eda.nokia.com/v1alpha1
kind: Fabric
metadata:
  name: sunnyvale-dc1
spec:
  borderLeafs:
    borderLeafNodeSelector: 
      - eda.nokia.com/role=borderleaf
  leafs:
    leafNodeSelector: 
      - eda.nokia.com/role=leaf
  spines:
    spineNodeSelector: 
      - eda.nokia.com/role=spine
  interSwitchLinks:
    linkSelector: 
    - eda.nokia.com/role=interSwitch
    poolIPV4: ipv4-pool
  systemPoolIPV4: systemipv4-pool
  underlayProtocol:
    asnPool: asn-pool
    protocol:
      - EBGP
  overlayProtocol:
    protocol: EBGP
EOF

apiVersion: fabrics.eda.nokia.com/v1alpha1
kind: Fabric
metadata:
  name: sunnyvale-dc1
spec:
  borderLeafs:
    borderLeafNodeSelector: 
      - eda.nokia.com/role=borderleaf
  leafs:
    leafNodeSelector: 
      - eda.nokia.com/role=leaf
  spines:
    spineNodeSelector: 
      - eda.nokia.com/role=spine
  interSwitchLinks:
    linkSelector: 
    - eda.nokia.com/role=interSwitch
    poolIPV4: ipv4-pool
  systemPoolIPV4: systemipv4-pool
  underlayProtocol:
    asnPool: asn-pool
    protocol:
      - EBGP
  overlayProtocol:
    protocol: EBGP

How easy was that? But what actually happened?

The Fabric app that comes preinstalled in EDA just created a bunch of lower-level abstractions that make up a DC fabric — inter-switch links (ISLs), BGP peers, BGP groups, interfaces, etc. These abstractions were created by the Fabric app and then translated into node-specific configurations, which were pushed to your topology!

You can also use kubectl to view the status of your newly created Fabric and all the lower-level abstractions it generated!

kubectl get isl

You may as well take a look at the other sub resource like BGP groups that were created by the same Fabric app. Using the YAML format that provides a more detailed view of the resource configuration and state.

kubectl get DefaultBGPGroup bgpgroup-ebgp-sunnyvale-dc1 -o yaml

Step 2: Trust but verify with K9s#

Let's verify that something actually happened, but this time let's use another K8s tool — a popular CLI UI called K9s.

From your terminal, simply type k9s to launch the UI.

You will be shown a list of K8s pods. Let’s take a look at our newly deployed Fabric by pressing : followed by typing fabrics and pressing enter.

Note its operational state. The Fabric emits multiple other abstractions such as Interswitch Links (ISLs); let's take a look at those!

Press : followed by isls and press enter.

To see more details about a particular ISL, press d while one of the ISLs is selected.

Step 3 (Optional): Clicky click with Headlamp UI#

While DevOps folks tend to prefer CLI tools and text editors, the UI world is also a great place to be. Again, leveraging the K8s-powered open-source ecosystem, we deployed the Headlamp UI in our cluster to provide a web-based UI for interacting with the cluster.

To access the UI, you need to fetch the login token that is patiently waiting for you in your terminal:

cat ~/hl-token

The output should be a string like this:

eyJhbGciOiJSUaaaSomeLongStringaaazI1NiIsImtpZXhwSomeLongString...

Copy the token and open up the Headlamp UI in a browser by visiting the following HTTP URL:

When prompted for the token, paste the token you copied earlier.

Using the Headlamp K8s web UI lets make a change to our Fabric resource and see its impact on DefaultBGPPeers.

Lets change the pool used for the Interswitch Links from IPv4 to IPv6.