Azure CNI

This guide explains how to set up Cilium in combination with Azure CNI. In this hybrid mode, the Azure CNI plugin is responsible for setting up the virtual network devices as well as address allocation (IPAM). After the initial networking is setup, the Cilium CNI plugin is called to attach BPF programs to the network devices set up by Azure CNI to enforce network policies, perform load-balancing, and encryption.

Note

If you are looking to install Cilium on Azure AKS, see the guide Installation on Azure AKS for a complete guide also covering cluster setup.

Create an AKS + Cilium CNI configuration

Create a chaining.yaml file based on the following template to specify the desired CNI chaining configuration:

apiVersion: v1
kind: ConfigMap
metadata:
  name: cni-configuration
  namespace: cilium
data:
  cni-config: |-
    {
      "cniVersion": "0.3.0",
      "name": "azure",
      "plugins": [
        {
          "type": "azure-vnet",
          "mode": "transparent",
          "bridge": "azure0",
          "ipam": {
             "type": "azure-vnet-ipam"
           }
        },
        {
          "type": "portmap",
          "capabilities": {"portMappings": true},
          "snat": true
        },
        {
           "name": "cilium",
           "type": "cilium-cni"
        }
      ]
    }

Create the cilium namespace:

kubectl create namespace cilium

Deploy the ConfigMap:

kubectl apply -f chaining.yaml

Deploy Cilium

Note

First, make sure you have Helm 3 installed.

If you have (or planning to have) Helm 2 charts (and Tiller) in the same cluster, there should be no issue as both version are mutually compatible in order to support gradual migration. Cilium chart is targeting Helm 3 (v3.0.3 and above).

Setup Helm repository:

helm repo add cilium https://helm.cilium.io/

Deploy Cilium release via Helm:

helm install cilium cilium/cilium --version 1.8.1 \
  --namespace cilium \
  --set global.cni.chainingMode=generic-veth \
  --set global.cni.customConf=true \
  --set global.nodeinit.enabled=true \
  --set nodeinit.azure=true \
  --set global.cni.configMap=cni-configuration \
  --set global.tunnel=disabled \
  --set global.masquerade=false

This will create both the main cilium daemonset, as well as the cilium-node-init daemonset, which handles tasks like mounting the BPF filesystem and updating the existing Azure CNI plugin to run in ‘transparent’ mode.

Restart existing pods

The new CNI chaining configuration will not apply to any pod that is already running in the cluster. Existing pods will be reachable and Cilium will load-balance to them but policy enforcement will not apply to them and load-balancing is not performed for traffic originating from existing pods. You must restart these pods in order to invoke the chaining configuration on them.

If you are unsure if a pod is managed by Cilium or not, run kubectl get cep in the respective namespace and see if the pod is listed.

Validate the Installation

You can monitor as Cilium and all required components are being installed:

kubectl -n cilium get pods --watch
NAME                                    READY   STATUS              RESTARTS   AGE
cilium-operator-cb4578bc5-q52qk         0/1     Pending             0          8s
cilium-s8w5m                            0/1     PodInitializing     0          7s

It may take a couple of minutes for all components to come up:

cilium-operator-cb4578bc5-q52qk         1/1     Running   0          4m13s
cilium-s8w5m                            1/1     Running   0          4m12s

Deploy the connectivity test

You can deploy the “connectivity-check” to test connectivity between pods.

kubectl apply -f https://raw.githubusercontent.com/cilium/cilium/1.8.1/examples/kubernetes/connectivity-check/connectivity-check.yaml

It will deploy a series of deployments which will use various connectivity paths to connect to each other. Connectivity paths include with and without service load-balancing and various network policy combinations. The pod name indicates the connectivity variant and the readiness and liveness gate indicates success or failure of the test:

NAME                                                    READY   STATUS    RESTARTS   AGE
echo-a-5995597649-f5d5g                                 1/1     Running   0          4m51s
echo-b-54c9bb5f5c-p6lxf                                 1/1     Running   0          4m50s
echo-b-host-67446447f7-chvsp                            1/1     Running   0          4m50s
host-to-b-multi-node-clusterip-78f9869d75-l8cf8         1/1     Running   0          4m50s
host-to-b-multi-node-headless-798949bd5f-vvfff          1/1     Running   0          4m50s
pod-to-a-59b5fcb7f6-gq4hd                               1/1     Running   0          4m50s
pod-to-a-allowed-cnp-55f885bf8b-5lxzz                   1/1     Running   0          4m50s
pod-to-a-external-1111-7ff666fd8-v5kqb                  1/1     Running   0          4m48s
pod-to-a-l3-denied-cnp-64c6c75c5d-xmqhw                 1/1     Running   0          4m50s
pod-to-b-intra-node-845f955cdc-5nfrt                    1/1     Running   0          4m49s
pod-to-b-multi-node-clusterip-666594b445-bsn4j          1/1     Running   0          4m49s
pod-to-b-multi-node-headless-746f84dff5-prk4w           1/1     Running   0          4m49s
pod-to-b-multi-node-nodeport-7cb9c6cb8b-ksm4h           1/1     Running   0          4m49s
pod-to-external-fqdn-allow-google-cnp-b7b6bcdcb-tg9dh   1/1     Running   0          4m48s

Note

If you deploy the connectivity check to a single node cluster, pods that check multi-node functionalities will remain in the Pending state. This is expected since these pods need at least 2 nodes to be scheduled successfully.

Specify Environment Variables

Specify the namespace in which Cilium is installed as CILIUM_NAMESPACE environment variable. Subsequent commands reference this environment variable.

export CILIUM_NAMESPACE=kube-system

Enable Hubble

Hubble is a fully distributed networking and security observability platform for cloud native workloads. It is built on top of Cilium and eBPF to enable deep visibility into the communication and behavior of services as well as the networking infrastructure in a completely transparent manner.

  • Hubble can be configured to be in local mode or distributed mode (beta).

    In local mode, Hubble listens on a UNIX domain socket. You can connect to a Hubble instance by running hubble command from inside the Cilium pod. This provides networking visibility for traffic observed by the local Cilium agent.

    helm upgrade cilium cilium/cilium --version 1.8.1 \
       --namespace $CILIUM_NAMESPACE \
       --reuse-values \
       --set global.hubble.enabled=true \
       --set global.hubble.metrics.enabled="{dns,drop,tcp,flow,port-distribution,icmp,http}"
    

    In distributed mode (beta), Hubble listens on a TCP port on the host network. This allows Hubble Relay to communicate with all the Hubble instances in the cluster. Hubble CLI and Hubble UI in turn connect to Hubble Relay to provide cluster-wide networking visibility.

    Warning

    In Distributed mode, Hubble runs a gRPC service over plain-text HTTP on the host network without any authentication/authorization. The main consequence is that anybody who can reach the Hubble gRPC service can obtain all the networking metadata from the host. It is therefore strongly discouraged to enable distributed mode in a production environment.

    helm upgrade cilium cilium/cilium --version 1.8.1 \
       --namespace $CILIUM_NAMESPACE \
       --reuse-values \
       --set global.hubble.enabled=true \
       --set global.hubble.listenAddress=":4244" \
       --set global.hubble.metrics.enabled="{dns,drop,tcp,flow,port-distribution,icmp,http}" \
       --set global.hubble.relay.enabled=true \
       --set global.hubble.ui.enabled=true
    
  • Restart the Cilium daemonset to allow Cilium agent to pick up the ConfigMap changes:

    kubectl rollout restart -n $CILIUM_NAMESPACE ds/cilium
    
  • To pick one Cilium instance and validate that Hubble is properly configured to listen on a UNIX domain socket:

    kubectl exec -n $CILIUM_NAMESPACE -t ds/cilium -- hubble observe
    
  • (Distributed mode only) To validate that Hubble Relay is running, install the hubble CLI:

    Download the latest hubble release:

    export HUBBLE_VERSION=$(curl -s https://raw.githubusercontent.com/cilium/hubble/master/stable.txt)
    curl -LO "https://github.com/cilium/hubble/releases/download/$HUBBLE_VERSION/hubble-linux-amd64.tar.gz"
    curl -LO "https://github.com/cilium/hubble/releases/download/$HUBBLE_VERSION/hubble-linux-amd64.tar.gz.sha256sum"
    sha256sum --check hubble-linux-amd64.tar.gz.sha256sum
    tar zxf hubble-linux-amd64.tar.gz
    

    and move the hubble CLI to a directory listed in the $PATH environment variable. For example:

    sudo mv hubble /usr/local/bin
    

    Download the latest hubble release:

    export HUBBLE_VERSION=$(curl -s https://raw.githubusercontent.com/cilium/hubble/master/stable.txt)
    curl -LO "https://github.com/cilium/hubble/releases/download/$HUBBLE_VERSION/hubble-darwin-amd64.tar.gz"
    curl -LO "https://github.com/cilium/hubble/releases/download/$HUBBLE_VERSION/hubble-darwin-amd64.tar.gz.sha256sum"
    shasum -a 256 -c hubble-darwin-amd64.tar.gz.sha256sum
    tar zxf hubble-darwin-amd64.tar.gz
    

    and move the hubble CLI to a directory listed in the $PATH environment variable. For example:

    sudo mv hubble /usr/local/bin
    

    Download the latest hubble release:

    curl -LO "https://raw.githubusercontent.com/cilium/hubble/master/stable.txt"
    set /p HUBBLE_VERSION=<stable.txt
    curl -LO "https://github.com/cilium/hubble/releases/download/%HUBBLE_VERSION%/hubble-windows-amd64.tar.gz"
    curl -LO "https://github.com/cilium/hubble/releases/download/%HUBBLE_VERSION%/hubble-windows-amd64.tar.gz.sha256sum"
    certutil -hashfile hubble-windows-amd64.tar.gz SHA256
    type hubble-windows-amd64.tar.gz.sha256sum
    :: verify that the checksum from the two commands above match
    tar zxf hubble-windows-amd64.tar.gz
    

    and move the hubble.exe CLI to a directory listed in the %PATH% environment variable after extracting it from the tarball.

    Once the hubble CLI is installed, set up a port forwarding for hubble-relay service and run hubble observe command:

    kubectl port-forward -n $CILIUM_NAMESPACE svc/hubble-relay 4245:80
    hubble observe --server localhost:4245
    

    (For Linux / MacOS) For convenience, you may set and export the HUBBLE_DEFAULT_SOCKET_PATH environment variable:

    $ export HUBBLE_DEFAULT_SOCKET_PATH=localhost:4245
    

    This will allow you to use hubble status and hubble observe commands without having to specify the server address via the --server flag.

  • (Distributed mode only) To validate that Hubble UI is properly configured, set up a port forwarding for hubble-ui service:

    kubectl port-forward -n $CILIUM_NAMESPACE svc/hubble-ui 12000:80
    

    and then open http://localhost:12000/.