> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Demo Installing Cilium on Kubernetes

> This guide explains how to deploy Cilium as a Kubernetes CNI and enable Hubble observability.

In this guide, you’ll learn how to deploy Cilium as your Kubernetes CNI and enable Hubble observability. We cover both the Cilium CLI and Helm methods, validate network connectivity, and demonstrate how to watch live network flows.

## Prerequisites

* A running Kubernetes cluster (v1.18+).
* `kubectl` configured to your target context.
* Cilium CLI (`cilium`) installed.
* Hubble CLI (`hubble`) installed.

<Callout icon="lightbulb" color="#1CB2FE">
  Verify your current context before proceeding:

  ```bash theme={null}
  kubectl config current-context
  ```
</Callout>

## 1. Installation Methods Compared

| Method     | Command Example                                                                               | Best For                              |
| ---------- | --------------------------------------------------------------------------------------------- | ------------------------------------- |
| Cilium CLI | `cilium install --version 1.15.4 --wait`                                                      | Rapid installs and upgrades           |
| Helm       | `helm upgrade cilium cilium/cilium --version 1.15.4 --namespace kube-system --reuse-values …` | Advanced customizations and overrides |

<Callout icon="triangle-alert" color="#FF6B6B">
  Mixing CLI and Helm installations without `--reuse-values` can lead to configuration drift. Always double-check your values before upgrading.
</Callout>

## 2. Install Cilium with the CLI

At the time of writing, **v1.15.4** is the latest stable release. Run:

```bash theme={null}
cilium install --version 1.15.4 --wait
```

The `--wait` flag blocks until all Cilium pods and operators are ready.

Verify status:

```bash theme={null}
cilium status
```

Expected output:

```plaintext theme={null}
Cilium:
    OK
Operator:
    OK
Envoy Daemon Set:
    disabled (using embedded mode)
Hubble Relay:
    disabled
ClusterMesh:
    disabled

Deployment
    cilium-operator      Desired: 1, Ready: 1/1, Available: 1/1
DaemonSet
    cilium              Desired: 2, Ready: 2/2, Available: 2/2
...
```

## 3. Validate Network Connectivity

Before enabling Hubble, confirm that Cilium networking works end-to-end:

```bash theme={null}
cilium connectivity test
```

This can take a few minutes. A timeout like:

```plaintext theme={null}
Connectivity test failed: timeout reached waiting for deployment cilium-test/client3 to become ready
```

indicates a readiness issue in one of the test pods.

## 4. Enable Hubble Observability via Helm

To add Hubble Relay and UI, upgrade your Cilium release in the `kube-system` namespace:

```bash theme={null}
helm repo add cilium https://helm.cilium.io/
helm repo update
helm upgrade cilium cilium/cilium --version 1.15.4 \
  --namespace kube-system \
  --reuse-values \
  --set hubble.relay.enabled=true \
  --set hubble.ui.enabled=true
```

Re-check Cilium’s status:

```bash theme={null}
cilium status
```

You should now see:

```plaintext theme={null}
Hubble Relay:      OK
Hubble UI:         OK
...
Cluster Pods:      X/Y managed by Cilium
```

## 5. Port-Forward Hubble Relay & Check Status

Port-forward the Relay service locally:

```bash theme={null}
cilium hubble port-forward
```

This sets up:

```bash theme={null}
kubectl port-forward -n kube-system svc/hubble-relay --address 127.0.0.1 4245:80
```

In a new terminal, query Hubble’s health:

```bash theme={null}
hubble status
```

Sample output:

```plaintext theme={null}
Healthcheck (via localhost:4245):
Current/Max Flows: 5,818/8,190 (71.04%)
Flows/s: 22.83
Connected Nodes: 2/2
```

## 6. Observe Live Network Flows

Stream live traffic and events:

```bash theme={null}
hubble observe
```

Example event:

```plaintext theme={null}
Jul 29 20:37:53.947: 10.0.0.77:46164 (host) <-- kube-system/coredns-... to-stack FORWARDED (TCP Flags: ACK, FIN)
...
```

You have successfully installed Cilium CNI and enabled Hubble observability on your Kubernetes cluster. Next, explore Cilium network policies and advanced Hubble filtering to secure and monitor traffic in production.

## Links and References

* [Cilium Documentation](https://docs.cilium.io/)
* [Hubble Observability Guide](https://docs.cilium.io/en/stable/gettingstarted/hubble/)
* [Kubernetes Networking Concepts](https://kubernetes.io/docs/concepts/cluster-administration/networking/)

<CardGroup>
  <Card title="Watch Video" icon="video" cta="Learn more" href="https://learn.kodekloud.com/user/courses/kubernetes-networking/module/5eea49e6-caea-4e84-88a0-268ea6f263af/lesson/6fd094cb-eaab-48d6-8b81-9867ac2a277a" />

  <Card title="Practice Lab" icon="installation" cta="Learn more" href="https://learn.kodekloud.com/user/courses/kubernetes-networking/module/5eea49e6-caea-4e84-88a0-268ea6f263af/lesson/68a3d25f-d6d8-4556-a0ef-f9a68db1e9f3" />
</CardGroup>