Setting up Cilium in AWS ENI mode

Note

The AWS ENI integration is still subject to some limitations. See Limitations for details.

Create an AWS cluster

Setup a Kubernetes on AWS. You can use any method you prefer, but for the simplicity of this tutorial, we are going to use eksctl. For more details on how to set up an EKS cluster using eksctl, see the section Installation on AWS EKS.

eksctl create cluster --name test-cluster --without-nodegroup

Disable VPC CNI (aws-node DaemonSet) (EKS only)

If you are running an EKS cluster, you should delete the aws-node DaemonSet.

Cilium will manage ENIs instead of VPC CNI, so the aws-node DaemonSet has to be deleted to prevent conflict behavior.

Note

Once aws-node DaemonSet is deleted, EKS will not try to restore it.

kubectl -n kube-system delete daemonset aws-node

Deploy Cilium

Note

First, make sure you have Helm 3 installed. Helm 2 is no longer supported.

Setup Helm repository:

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

Deploy Cilium release via Helm:

helm install cilium cilium/cilium --version 1.9.0 \
  --namespace kube-system \
  --set eni=true \
  --set ipam.mode=eni \
  --set egressMasqueradeInterfaces=eth0 \
  --set tunnel=disabled \
  --set nodeinit.enabled=true

Note

The above options are assuming that masquerading is desired and that the VM is connected to the VPC using eth0. It will route all traffic that does not stay in the VPC via eth0 and masquerade it.

If you want to avoid masquerading, set masquerade=false. You must ensure that the security groups associated with the ENIs (eth1, eth2, …) allow for egress traffic to outside of the VPC. By default, the security groups for pod ENIs are derived from the primary ENI (eth0).

Create a node group

eksctl create nodegroup --cluster test-cluster --nodes 2

Validate the Installation

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

kubectl -n kube-system get pods --watch
NAME                                    READY   STATUS              RESTARTS   AGE
cilium-operator-cb4578bc5-q52qk         0/1     Pending             0          8s
cilium-s8w5m                            0/1     PodInitializing     0          7s
coredns-86c58d9df4-4g7dd                0/1     ContainerCreating   0          8m57s
coredns-86c58d9df4-4l6b2                0/1     ContainerCreating   0          8m57s

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
coredns-86c58d9df4-4g7dd                1/1     Running   0          13m
coredns-86c58d9df4-4l6b2                1/1     Running   0          13m

Deploy the connectivity test

You can deploy the “connectivity-check” to test connectivity between pods. It is recommended to create a separate namespace for this.

kubectl create ns cilium-test

Deploy the check with:

kubectl apply -n cilium-test -f https://raw.githubusercontent.com/cilium/cilium/v1.9/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:

$ kubectl get pods -n cilium-test
NAME                                                     READY   STATUS    RESTARTS   AGE
echo-a-76c5d9bd76-q8d99                                  1/1     Running   0          66s
echo-b-795c4b4f76-9wrrx                                  1/1     Running   0          66s
echo-b-host-6b7fc94b7c-xtsff                             1/1     Running   0          66s
host-to-b-multi-node-clusterip-85476cd779-bpg4b          1/1     Running   0          66s
host-to-b-multi-node-headless-dc6c44cb5-8jdz8            1/1     Running   0          65s
pod-to-a-79546bc469-rl2qq                                1/1     Running   0          66s
pod-to-a-allowed-cnp-58b7f7fb8f-lkq7p                    1/1     Running   0          66s
pod-to-a-denied-cnp-6967cb6f7f-7h9fn                     1/1     Running   0          66s
pod-to-b-intra-node-nodeport-9b487cf89-6ptrt             1/1     Running   0          65s
pod-to-b-multi-node-clusterip-7db5dfdcf7-jkjpw           1/1     Running   0          66s
pod-to-b-multi-node-headless-7d44b85d69-mtscc            1/1     Running   0          66s
pod-to-b-multi-node-nodeport-7ffc76db7c-rrw82            1/1     Running   0          65s
pod-to-external-1111-d56f47579-d79dz                     1/1     Running   0          66s
pod-to-external-fqdn-allow-google-cnp-78986f4bcf-btjn7   0/1     Running   0          66s

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 for Cluster-Wide Visibility

Hubble is the component for observability in Cilium. To obtain cluster-wide visibility into your network traffic, deploy Hubble Relay and the UI with the following Helm upgrade command on your existing installation (Cilium agent pods will be restarted in the process).

helm upgrade cilium cilium/cilium --version 1.9.0 \
   --namespace $CILIUM_NAMESPACE \
   --reuse-values \
   --set hubble.listenAddress=":4244" \
   --set hubble.relay.enabled=true \
   --set hubble.ui.enabled=true

Once the Hubble UI pod is started, use port forwarding for the hubble-ui service. This allows opening the UI locally on a browser:

kubectl port-forward -n $CILIUM_NAMESPACE svc/hubble-ui --address 0.0.0.0 --address :: 12000:80

And then open http://localhost:12000/ to access the UI.

Hubble UI is not the only way to get access to Hubble data. A command line tool, the Hubble CLI, is also available. It can be installed by following the instructions below:

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.

Similarly to the UI, use port forwarding for the hubble-relay service to make it available locally:

kubectl port-forward -n $CILIUM_NAMESPACE svc/hubble-relay --address 0.0.0.0 --address :: 4245:80

In a separate terminal window, run the hubble status command specifying the Hubble Relay address:

$ hubble --server localhost:4245 status
Healthcheck (via localhost:4245): Ok
Current/Max Flows: 5455/16384 (33.29%)
Flows/s: 11.30
Connected Nodes: 4/4

If Hubble Relay reports that all nodes are connected, as in the example output above, you can now use the CLI to observe flows of the entire cluster:

hubble --server localhost:4245 observe

If you encounter any problem at this point, you may seek help on Slack.

Tip

Hubble CLI configuration can be persisted using a configuration file or environment variables. This avoids having to specify options specific to a particular environment every time a command is run. Run hubble help config for more information.

For more information about Hubble and its components, see the Observability section.

Limitations

  • The AWS ENI integration of Cilium is currently only enabled for IPv4.
  • When applying L7 policies at egress, the source identity context is lost as it is currently not carried in the packet. This means that traffic will look like it is coming from outside of the cluster to the receiving pod.

Troubleshooting

Make sure to disable DHCP on ENIs

Cilium will use both the primary and secondary IP addresses assigned to ENIs. Use of the primary IP address optimizes the number of IPs available to pods but can conflict with a DHCP agent running on the node and assigning the primary IP of the ENI to the interface of the node. A common scenario where this happens is if NetworkManager is running on the node and automatically performing DHCP on all network interfaces of the VM. Be sure to disable DHCP on any ENIs that get attached to the node or disable NetworkManager entirely.