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Istio integration

Calico policy integrates with Istio to allow you to write policies that enforce against application layer attributes like HTTP methods or paths as well as against cryptographically secure identities. In this lab we will enable this integration and test it out.

Install FlexVolume driver

Calico uses a FlexVolume driver to enable secure connectivity between Felix and the Dikastes container running in each pod. It mounts a shared volume into which Felix inserts a Unix Domain Socket.

On each node in the cluster, execute the following commands to install the FlexVolume driver binary.

sudo mkdir -p /usr/libexec/kubernetes/kubelet-plugins/volume/exec/nodeagent~uds
sudo docker run --rm \
  -v /usr/libexec/kubernetes/kubelet-plugins/volume/exec/nodeagent~uds:/host/driver \
  calico/pod2daemon-flexvol:v3.8.0

Verify the uds binary is present

ls -lh /usr/libexec/kubernetes/kubelet-plugins/volume/exec/nodeagent~uds

Result

total 5.0M
-r-xr-x--- 1 root root 5.0M Jul 25 22:31 uds

Enable policy sync API

Application layer policy requires the policy sync API to be enabled on Felix. To do this cluster-wide, modify the default FelixConfiguration to set the field policySyncPathPrefix to /var/run/nodeagent. The following example uses sed to modify your existing default config before re-applying it.

calicoctl get felixconfiguration default --export -o yaml | \
sed -e '/  policySyncPathPrefix:/d' \
    -e '$ a\  policySyncPathPrefix: /var/run/nodeagent' > felix-config.yaml
calicoctl apply -f felix-config.yaml

Installing Istio

Install Istio 1.1.7, including mutually authenticated TLS for service to service communication.

curl -L https://git.io/getLatestIstio | ISTIO_VERSION=1.1.7 sh -
cd $(ls -d istio-*)
kubectl apply -f install/kubernetes/helm/istio-init/files/
kubectl apply -f install/kubernetes/istio-demo-auth.yaml

Note: If an “unable to recognize” error occurs after applying install/kubernetes/istio-demo-auth.yaml it is likely a race condition between creating an Istio CRD and then a resource of that type. Re-run the kubectl apply.

Updating the Istio sidecar injector

The sidecar injector automatically modifies pods as they are created to work with Istio. This step modifies the injector configuration to add Dikastes, a Calico component, as sidecar containers.

Apply the following ConfigMap to enable injection of Dikastes alongside Envoy.

   kubectl apply -f https://docs.projectcalico.org/v3.8/manifests/alp/istio-inject-configmap-1.1.7.yaml

Adding Calico authorization services to the mesh

Apply the following manifest to configure Istio to query Calico for application layer policy authorization decisions

kubectl apply -f https://docs.projectcalico.org/v3.8/manifests/alp/istio-app-layer-policy.yaml

Adding namespace labels

Application layer policy is only enforced on pods that are started with the Envoy and Dikastes sidecars. Pods that do not have these sidecars will only enforce standard Calico network policy.

You can control this on a per-namespace basis. To enable Istio and application layer policy in a namespace, add the label istio-injection=enabled.

Label the default namespace, which you will use for the tutorial.

kubectl label namespace default istio-injection=enabled

Test application layer policy

You can test application layer policy by following the Application Layer Policy tutorial.