Amazon Web Services

Calico Cloud provides the following advantages when running in Amazon Web Services (AWS):

• Network Policy for Containers: Calico Cloud provides fine-grained network security policy for individual containers.
• No Overlays: Within each VPC subnet Calico Cloud doesn't need an overlay, which means high performance networking for your containers.
• No 50 Node Limit: Calico Cloud allows you to surpass the 50 node limit, which exists as a consequence of the AWS 50 route limit when using the VPC routing table.

Routing traffic within a single VPC subnet

Since Calico Cloud assigns IP addresses outside the range used by AWS for EC2 instances, you must disable AWS src/dst checks on each EC2 instance in your cluster as described in the AWS documentation. This allows Calico Cloud to route traffic natively within a single VPC subnet without using an overlay or any of the limited VPC routing table entries.

Routing traffic across different VPC subnets / VPCs

If you need to split your deployment across multiple AZs for high availability then each AZ will have its own VPC subnet. To use Calico Cloud across multiple different VPC subnets or peered VPCs, in addition to disabling src/dst checks as described above you must also enable IPIP encapsulation and outgoing NAT on your Calico Cloud IP pools.

See the IP pool configuration reference for information on how to configure Calico Cloud IP pools.

By default, Calico Cloud's IPIP encapsulation applies to all container-to-container traffic. However, encapsulation is only required for container traffic that crosses a VPC subnet boundary. For better performance, you can configure Calico Cloud to perform IPIP encapsulation only across VPC subnet boundaries.

To enable the "CrossSubnet" IPIP feature, configure your Calico Cloud IP pool resources to enable IPIP and set the mode to "CrossSubnet".

note

This feature was introduced in Calico Cloud v2.1, if your deployment was created with an older version of Calico Cloud, or if you if you are unsure whether your deployment is configured correctly, follow the Configuring IP-in-IP guide which discusses this in more detail.

The following kubectl command will create or modify an IPv4 pool with CIDR 192.168.0.0/16 using IPIP mode CrossSubnet. Adjust the pool CIDR for your deployment.

kubectl apply -f - <<EOF
apiVersion: projectcalico.org/v3
kind: IPPool
metadata:
  name: ippool-cs-1
spec:
  cidr: 192.168.0.0/16
  ipipMode: CrossSubnet
EOF

Enabling workload-to-WAN traffic

To allow Calico Cloud networked containers to reach resources outside of AWS, you must configure outgoing NAT on your Calico Cloud IP pool.

AWS will perform outbound NAT on any traffic which has the source address of an EC2 virtual machine instance. By enabling outgoing NAT on your Calico Cloud IP pool, Calico Cloud will NAT any outbound traffic from the containers hosted on the EC2 virtual machine instances.

The following kubectl command will create or modify an IPv4 pool with CIDR 192.168.0.0/16 using IPIP mode CrossSubnet and enables outgoing NAT. Adjust the pool CIDR for your deployment.

kubectl apply -f - <<EOF
apiVersion: projectcalico.org/v3
kind: IPPool
metadata:
  name: ippool-1
spec:
  cidr: 192.168.0.0/16
  ipipMode: CrossSubnet
  natOutgoing: true
EOF

Using AWS networking

Calico Cloud supports the AWS VPC CNI plugin, which creates ENI interfaces for the pods that fall within the VPC of the cluster. Routing to these pods is automatically handled by AWS.

We recommend using the AWS VPC CNI plugin with federation as it provides seamless IP connectivity between your AWS cluster and a remote cluster. Ensure that you use version 1.1 or later.

Install the AWS VPC CNI plugin in your Kubernetes cluster as follows.

1. Download the AWS VPC CNI manifest.

   curl \
   https://raw.githubusercontent.com/aws/amazon-vpc-cni-k8s/v1.11.4/config/master/aws-k8s-cni.yaml \
   -O

2. By default, the AWS CNI plugin performs SNAT for any packet routed outside the VPC. You must disable SNAT on external packets to allow clusters in other VPCs or connected via VPN to communicate with pods.

   caution

   Required for federation.

   To disable SNAT on external packets, open the AWS VPC CNI manifest in your favorite editor and add an AWS_VPC_K8S_CNI_EXTERNALSNAT environment variable set to true in the aws-node container. An example follows.

   kind: DaemonSet
   apiVersion: apps/v1
   # kubernetes versions before 1.9.0 should use extensions/v1beta1
   metadata:
     name: aws-node
     namespace: kube-system
     labels:
       k8s-app: aws-node
   spec:
     updateStrategy:
       type: RollingUpdate
     selector:
       matchLabels:
         k8s-app: aws-node
     template:
       metadata:
         labels:
           k8s-app: aws-node
         annotations:
           scheduler.alpha.kubernetes.io/critical-pod: ''
       spec:
         serviceAccountName: aws-node
         hostNetwork: true
         tolerations:
           - operator: Exists
         containers:
           - image: 602401143452.dkr.ecr.us-west-2.amazonaws.com/amazon-k8s-cni:v1.3.4
             imagePullPolicy: Always
             ports:
               - containerPort: 61678
                 name: metrics
             name: aws-node
             env:
               - name: AWS_VPC_K8S_CNI_LOGLEVEL
                 value: DEBUG
               - name: MY_NODE_NAME
                 valueFrom:
                   fieldRef:
                     fieldPath: spec.nodeName
               - name: AWS_VPC_K8S_CNI_EXTERNALSNAT
                 value: 'true'
   note

   For details see the Amazon VPC CNI Plugin Version 1.1 release notes.

3. Apply the manifest using kubectl.

   kubectl apply -f aws-k8s-cni.yaml

4. Follow the instructions to install Calico Cloud on AWS.