Installing Cilium

Last updated: 2024-02-02

There is some great documentation on Cilium on the Isovalent site and on Github. This article draws on that documentation and whittles it down to focus on using a Windows client to install Cilium on an Azure AKS cluster.

The first thing to do is head over to the releases page of the Cilium Gihub repo. We are using a Windows client so we selected the cilium-windows-amd64.tar.gz archive. Next you just need to extract the tar archive, copy the exe to your preferred location on disk and then add the location to your path. That's all there is to it!

Next we will just verify that everything is working correctly:

Next we need to create our AKS cluster. The critical thing here is that we do not install any network plug-in at this point. This is taken care of by the --network-plugin none parameter. It is normally my preference to attach the cluster to a container registry and specify a custom vm size but these parameters are optional.

 az aks create --resource-group {your-resource-group} --name {your-cluster-name} --node-count 2  --generate-ssh-keys --attach-acr {your-container-registry} --network-plugin none --node-vm-size Standard_B2s 

Once the cluster has been provisioned, we just need to get credentials:

 az aks get-credentials --resource-group {your-resource-group} --name {your-cluster-name} --overwrite-existing 

The next step may seem slightly odd, but the guidance suggests cloning the Cilium GitHub repo. This means that the Cilium Cli can point to a fresh version of the Helm values chart when you run the install onto your cluster. Clone the Cilium repo:

   git clone               

Next, we will install Cilium onto our cluster. There are two methods for this.

Method 1 - Cilium CLI
This will install Cilium into your cluster using Helm in the background - you do not have to explicitly invoke any Helm commands yourself.

 cilium install --chart-directory cilium-main/install/kubernetes/cilium --set azure.resourceGroup="{your-resource-group}"  

You should see an output something like this - with some nice colourful icons:

Method 2 - Helm
Instead of using the Cilium CLI, you can use the standard Helm install procedure:

helm repo add cilium 
helm upgrade --install cilium cilium/cilium  

Obviously, if you are using this method (and you are familiar with Cilium configuration), you can also pass in Helm overrides:

helm repo add cilium 
helm upgrade --install cilium cilium/cilium --version 1.13.0-rc3 \ 
    --namespace kube-system \ 
    --set sctp.enabled=true \ 
    --set hubble.enabled=true \ 
    --set hubble.metrics.enabled="{dns,drop,tcp,flow,icmp,http}" \ 
    --set hubble.relay.enabled=true \ 
    --set hubble.ui.enabled=true \ 
    --set hubble.ui.service.type=NodePort \ 
    --set hubble.relay.service.type=NodePort 

For a fuller discussion of options on installing Cilium in to your cluster see this article by Nico Vibert.

To validate the installation run :

cilium status --wait  

In Windows Terminal you can expect a response something like this:

Next we need to verify that network connectivity in our cluster is functioning properly:

cilium connectivity test  

These tests may take quite a while and you will see quite a long series of notifications in your terminal window:

As you can see, some tests will be skipped if they are not relevant for your current cluster configuration:

Luckily, we seem to have a clean bill of health:

That's it! Cilium is now successfully installed on our cluster!

Exploring with the Cilium API

Now that Cilium is running on our cluster, we can take a look at the resources it has installed. The first thing is to view the pods it has created. By default they are installed in the cilium-test namespace:

As well as the pods, the install also creates a number of services. As you can see, the Hubble-related services are installed into the kube-system namespace.

OK - let's dive into a Cilium container and have a look around. First we will run the kubectl exec command to get a shell to the container:

 kubectl exec -ti cilium-c7c78 -n kube-system -- bash 

You should see a prompt something like this

Endpoints are a fundamental concept in Cilium. The most simple command we can run on them is simply to get a list:

 cilium endpoint list 

This gives us a high level view of the Endpoints that reside on a particular node. Endpoints can include pods in a Kubernetes environment, VMs, or bare-metal interfaces that Cilium manages for applying network policies, routing, and visibility.

If we want to drill down into the internals of our Endpoints we can use the bpf command

 cilium bpf endpoint list 

You should now see an output like this.

This returns a hash table of the endpoints running on the local machine. It lists the BPF maps and other BPF-related state information that Cilium maintains for each endpoint. Having looked at our endpoint, the next thing we might want to do is inspect the state of our environment. The cilium connectivity test command is a very powerful tool that possibly does more than the name actually suggests. This will run tests across a number of dimensions.

  • pod to pod within a node
  • pod to pod across nodes
  • pod to nodeport
  • etc
As well as this it will also validate our network policies.

Note! We are running the command below from our terminal - not from our container session:

 cilium connectivity test 

In the screnshot below we can see detailed information about our endpoint connectivity as well as the status of our network policies:


Cilium consists of a number of components. Hubble is the observability component of Cilium and provides network visibility and security observability for cloud-native workloads. If you have ever wanted a visualisation of the flow of traffic on your Kubernetes cluster, then this is exactly what Hubble can provide. When you install Cilium, Hubble is normally disabled by default. Our first task, therefore, is obviously to enable it:

cilium hubble enable 

Once it is enabled, we will run a quick status check:

cilium status 

Things seem to be looking pretty healthy:

We can now look at the Cilium Hubble commands. We will run these commands from the Cilium container running in Kube-system We will start off with the hubble status command:

hubble status  

This will give us a summary of network flows

Next, the observe command really gives us great visibility of network activity across the entire cluster:

if we like, we can filter this by pod:

hubble observe --pod cilium-test/echo-other-node-7b55b68c-qdb22 

Observe provides an in-memory store of network activity over the past n minutes. The value for n can be configured.

We have looked at the Hubble command line - however, the service also exposes a UI. First of all, we need to enable it. For this we will exit from our container and revert to our Windows terminal:

cilium hubble enable --ui 

Once the command completes you will see that you now have a hubble-ui pod running in your cluster;

If we now run the cilium hubble ui command, Cilium will set up port forwarding and connect to the UI in a browser. This is pretty cool - you don't even need to explicity set up the port-forwrding:

Once the browser opens up we can start exploring network flows in our cluster namespaces:

If you click on a record in the grid you can get more detail for a flow:

This is a really powerful and simple UI for exploring connectivity and flows across our cluster.


This has been a very brief introduction to getting Cilium up an running in an Azure AKS cluster. Cilium is a revolutionary and enormously powerful tool - both for analytics and diagnostics as well as for managing policies or even taking complete control of all traffic on a cluster. It presents engineers with almost unlimited possibilities for inspecting, managing and re-directing traffic flows. We will explore these possibilities in future articles. Cilium is an open source CNCF project and practitioners can now obtain a CNCF approved certification. You can find more details on the Isovalent GitHub site.

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