Integrations

This guide describes AppSwitch’s integration with Kubernetes and Istio.

Kubernetes

AppSwitch can serve as the network backend for Kubernetes. In a Kubernetes cluster, AppSwitch can be deployed with the DaemonSet spec like below. The only required customization before creating the DaemonSet is args: a comma-separated list of one or more of existing nodes in the AppSwitch cluster (Eg., args: ["--neighbors","<ip1>,<ip2>"]). For simplicity and availability, all nodes in the Kubernetes cluster shown by kubectl get nodes can be added.

---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: kube-appswitch
  namespace: kube-system
  labels:
    k8s-app: appswitch
spec:
  selector:
    matchLabels:
      name: kube-appswitch
  template:
    metadata:
      labels:
        name: kube-appswitch
    spec:
      hostNetwork: true
      hostPID: true
      containers:
      - name: appswitch-daemon
        image: appswitch/ax
        args: ["--neighbors","<ip1>,<ip2>"]
        resources:
          requests:
            cpu: "200m"
            memory: "200Mi"
          limits:
            cpu: "200m"
            memory: "200Mi"
        securityContext:
          privileged: true
        volumeMounts:
        - name: bin
          mountPath: /usr/bin
        - name: sock
          mountPath: /var/run/appswitch
      volumes:
        - name: bin
          hostPath:
            path: /usr/bin
        - name: sock
          hostPath:
            path: /var/run/appswitch

Then the DaemonSet itself can be created as follows.

$ kubectl create -f kube-daemonset.yaml

At this point, the Kubernetes cluster is primed to run applications based on AppSwitch. The pod spec needs a few small changes to use AppSwitch. This sample nginx pod spec illustrates those changes:

apiVersion: v1
kind: Pod
metadata:
  name: nginx
spec:
  containers:
  - name: nginx
    image: nginx
    command: ['/usr/bin/ax','run','--ip','1.1.1.1',nginx, '-g', 'daemon off;']
    ports:
    - containerPort: 80
    volumeMounts:
      - name: bin
        mountPath: /usr/bin/ax
      - name: run
        mountPath: /var/run/appswitch
  volumes:
    - name: bin
      hostPath:
        path: /usr/bin/ax
    - name: run
      hostPath:
        path: /var/run/appswitch

This creates an nginx pod enabled to run with AppSwitch. The changes from a typical nginx pod spec are:

• command is prefixed with ax and its parameters
• /usr/bin/ax and /var/run/appswitch host paths are mounted into the container

The application can be deployed to the cluster the normal way.

$ kubectl create -f nginx.yaml

Once deployed, you can connect to this nginx pod from any node in the cluster as follows.

$ ax run --ip 2.2.2.2 curl -I 1.1.1.1
HTTP/1.1 200 OK
Server: nginx/1.12.2
Date: Tue, 20 Mar 2018 21:21:22 GMT
Content-Type: text/html
Content-Length: 3700
Last-Modified: Wed, 18 Oct 2017 08:08:18 GMT
Connection: keep-alive
ETag: "59e70bf2-e74"
X-Backend-Server: host2
Accept-Ranges: bytes

Istio

AppSwitch is integrated with Istio to serve as a highly efficient dataplane through the AppSwitch Istio agent that consumes Pilot (XDS) API and conveys traffic management policies to AppSwitch.