sesispla / aci-bridge-k8s

Experimental ACI Bridge for Kubernetes

ACI Bridge for Kubernetes (experimental)

ACI Bridge for Kubernetes is an open-source connector that enables Kubernetes clusters to deploy Azure Container Instances.

This enables on-demand and nearly instantaneous container compute, orchestrated by Kubernetes, without having VM infrastructure to manage and while still leveraging the portable Kubernetes API. This will allow you to utilize both VMs and container instances simultaneously in the same K8s cluster, giving you the best of both worlds.

Please note this software is experimental and should not be used for anything resembling a production workload.

How does it Work

The ACI Bridge roughly mimics the Kubelet interface by:

• Registering into the Kubernetes data plane as a Node with unlimited capacity
• Dispatching scheduled Pods to Azure Container Instances instead of a VM-based container engine

Once the bridge is registered as a node called aci-bridge, you can use nodeName: aci-bridge in your Pod spec run the Pod via ACI. Pods without this node selector will continue to be scheduled normally.

Requirements

1. A working az command-line client
2. A Kubernetes cluster with a working kubectl

Quickstart

1. Edit examples/aci-bridge.yaml and supply environment variables
2. Run the ACI Bridge with kubectl create -f examples/aci-bridge.yaml
3. Wait for kubectl get nodes to display the aci-bridge node
4. Run an NGINX pod via ACI using kubectl create -f examples/nginx-pod.yaml
5. Access the NGINX pod via its public address

Usage

Create a Service Principal

A service principal is required to allow the ACI Bridge to create resources in your Azure subscription. You can create one using the az CLI using the instructions below.

Find your subscriptionId with the az CLI:

$ az account list -o table
Name                                             CloudName    SubscriptionId                        State    IsDefault
-----------------------------------------------  -----------  ------------------------------------  -------  -----------
Pay-As-You-Go                                    AzureCloud   12345678-9012-3456-7890-123456789012  Enabled  True

Use az to create a Service Principal that can perform operations on your subscription:

$ az ad sp create-for-rbac --role=Contributor --scopes /subscriptions/<subscription-id>
{
  "appId": "<redacted>",
  "displayName": "azure-cli-2017-07-19-19-13-19",
  "name": "http://azure-cli-2017-07-19-19-13-19",
  "password": "<redacted>",
  "tenant": "<redacted>"
}

Edit the examples/aci-bridge.yaml and input environment variables using the values above:

• AZURE_CLIENT_ID:
• AZURE_CLIENT_KEY:
• AZURE_TENANT_ID:
• AZURE_SUBSCRIPTION_ID:

Create a Resource Group

The ACI Bridge will create each container instance in a specified resource group. You can create a new resource group with:

$ az group create -n aci-test -l westus
{
  "id": "/subscriptions/<subscriptionId>/resourceGroups/aci-test",
  "location": "westus",
  "managedBy": null,
  "name": "aci-test",
  "properties": {
    "provisioningState": "Succeeded"
  },
  "tags": null
}

Edit the examples/aci-bridge.yaml and put the name of the resource group into the ACI_RESOURCE_GROUP environment variable.

Install the ACI Bridge

$ kubectl create -f examples/aci-bridge.yaml 
pod "aci-bridge" created

$ kubectl get nodes -w
NAME                        STATUS                     AGE       VERSION
aci-bridge                  Ready                      3s        1.6.6
k8s-agentpool1-31868821-0   Ready                      5d        v1.7.0
k8s-agentpool1-31868821-1   Ready                      5d        v1.7.0
k8s-agentpool1-31868821-2   Ready                      5d        v1.7.0
k8s-master-31868821-0       Ready,SchedulingDisabled   5d        v1.7.0

Install the NGINX example

$ kubectl create -f examples/nginx-pod.yaml 
pod "nginx" created

$ kubectl get po -w -o wide
NAME         READY     STATUS    RESTARTS   AGE       IP             NODE
aci-bridge   1/1       Running   0          44s       10.244.2.21    k8s-agentpool1-31868821-2
nginx        1/1       Running   0          31s       13.88.27.150   aci-bridge

Note the pod is scheduled on the aci-bridge node. It should now be accessible at the public IP listed.

Development Instructions

Local Development

<edit source>
$ make clean
$ make build
$ tsc bridge.ts
$ node bridge.js

Docker Development

make docker-build
docker tag <local-image> <remote-image>
docker push <remote-image>

Then edit examples/aci-bridge.yaml to point to the remote-image.

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.microsoft.com.

When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact [email protected] with any additional questions or comments.