Azure Container Instances (ACI) provide a hosted environment for running containers in Azure. When using ACI, there is no need to manage the underlying compute infrastructure, Azure handles this management for you. When running containers in ACI, you are charged by the second for each running container.
The Azure Container Instances provider for the Virtual Kubelet configures an ACI instance as a node in any Kubernetes cluster. When using the Virtual Kubelet ACI provider, pods can be scheduled on an ACI instance as if the ACI instance is a standard Kubernetes node. This configuration allows you to take advantage of both the capabilities of Kubernetes and the management value and cost benefit of ACI.
This document details configuring the Virtual Kubelet ACI provider.
- Prerequiste
- Quick set-up with the ACI Connector
- Manual set-up
- Validate the Virtual Kubelet ACI provider
- Schedule a pod in ACI
- Upgrade the ACI Connector
- Remove the Virtual Kubelet
This guide assumes that you have a Kubernetes cluster up and running (can be minikube
) and that kubectl
is already configured to talk to it.
Other pre-requesites are:
- A Microsoft Azure account.
- Install the Azure CLI.
- Install the Kubernetes CLI.
- Install the Helm CLI.
Install az
by following the instructions for your operating system.
See the full installation instructions if yours isn't listed below.
brew install azure-cli
Download and run the Azure CLI Installer (MSI).
- Add the azure-cli repo to your sources:
echo "deb [arch=amd64] https://packages.microsoft.com/repos/azure-cli/ wheezy main" | \ sudo tee /etc/apt/sources.list.d/azure-cli.list
- Run the following commands to install the Azure CLI and its dependencies:
sudo apt-key adv --keyserver packages.microsoft.com --recv-keys 52E16F86FEE04B979B07E28DB02C46DF417A0893 sudo apt-get install apt-transport-https sudo apt-get update && sudo apt-get install azure-cli
Install kubectl
by running the following command:
az aks install-cli
Helm is a tool for installing pre-configured applications on Kubernetes.
Install helm
by running the following command:
brew install kubernetes-helm
- Download the latest Helm release.
- Decompress the tar file.
- Copy helm.exe to a directory on your PATH.
curl https://raw.githubusercontent.com/kubernetes/helm/master/scripts/get | bash
Now that we have all the tools, we will set up your Azure account to work with ACI.
First let's identify your Azure subscription and save it for use later on in the quickstart.
-
Run
az login
and follow the instructions in the command output to authorizeaz
to use your account -
List your Azure subscriptions:
az account list -o table
-
Copy your subscription ID and save it in an environment variable:
Bash
export AZURE_SUBSCRIPTION_ID="<SubscriptionId>"
PowerShell
$env:AZURE_SUBSCRIPTION_ID = "<SubscriptionId>"
The Azure cli can be used to install the ACI provider. We like to say Azure's provider or implementation for Virtual Kubelet is the ACI Connector. For this section Virtual Kubelet's specific ACI provider will be referenced as the the ACI Connector. If you continue with this section you can skip sections below up to "Schedule a pod in ACI", as we use Azure Container Service (AKS) to easily deploy and install the connector, thus it is assumed that you've created an AKS cluster.
To install the ACI Connector use the az cli and the aks namespace. Make sure to use the resource group of the aks cluster you've created and the name of the aks cluster you've created. You can choose the connector name to be anything. Choose any command below to install the Linux, Windows, or both the Windows and Linux Connector.
Note: You need to specify the --aci-resource-group, due to a bug in the az cli. The resource groupis the auto-generated. To find the name navigate to the Azure Portal resource groups, scroll down and find the name that matches MC_aks cluster name_aks rg_location.
-
Install the Linux ACI Connector
Bash
az aks install-connector --resource-group <aks cluster rg> --name <aks cluster name> --os-type linux --connector-name myaciconnector --aci-resource-group <auto-generated aks cluster rg>
-
Install the Windows ACI Connector
Bash
az aks install-connector --resource-group <aks cluster rg> --name <aks cluster name> --os-type windows --connector-name myaciconnector --aci-resource-group <auto-generated aks cluster rg>
-
Install both the Windows and Linux ACI Connectors
Bash
az aks install-connector --resource-group <aks cluster rg> --name <aks cluster name> --os-type both --connector-name myaciconnector --aci-resource-group <auto-generated aks cluster rg>
Now you are ready to deploy a pod to the connector so skip to the "Schedule a pod in ACI" section.
To use Azure Container Instances, you must provide a resource group. Create one with the az cli using the following command.
export ACI_REGION=eastus
az group create --name aci-group --location "$ACI_REGION"
export AZURE_RG=aci-group
This creates an identity for the Virtual Kubelet ACI provider to use when provisioning resources on your account on behalf of Kubernetes.
-
Create a service principal with RBAC enabled for the quickstart:
az ad sp create-for-rbac --name virtual-kubelet-quickstart -o table
-
Save the values from the command output in environment variables:
Bash
export AZURE_TENANT_ID=<Tenant> export AZURE_CLIENT_ID=<AppId> export AZURE_CLIENT_SECRET=<Password>
PowerShell
$env:AZURE_TENANT_ID = "<Tenant>" $env:AZURE_CLIENT_ID = "<AppId>" $env:AZURE_CLIENT_SECRET = "<Password>"
You will need to enable ACI in your subscription:
```cli
az provider register -n Microsoft.ContainerInstance
```
Run these commands to deploy the virtual kubelet which connects your Kubernetes cluster to Azure Container Instances.
If your cluster is an AKS cluster:
export VK_RELEASE=virtual-kubelet-for-aks-0.1.3
For any other type of Kubernetes cluster:
export VK_RELEASE=virtual-kubelet-0.1.1
RELEASE_NAME=virtual-kubelet
NODE_NAME=virtual-kubelet
CHART_URL=https://github.com/virtual-kubelet/virtual-kubelet/raw/master/charts/$VK_RELEASE.tgz
curl https://raw.githubusercontent.com/virtual-kubelet/virtual-kubelet/master/scripts/createCertAndKey.sh > createCertAndKey.sh
chmod +x createCertAndKey.sh
. ./createCertAndKey.sh
helm install "$CHART_URL" --name "$RELEASE_NAME" \
--set env.azureClientId="$AZURE_CLIENT_ID",env.azureClientKey="$AZURE_CLIENT_SECRET",env.azureTenantId="$AZURE_TENANT_ID",env.azureSubscriptionId="$AZURE_SUBSCRIPTION_ID",env.aciRegion="$ACI_REGION",env.aciResourceGroup="$AZURE_RG",env.nodeName="$NODE_NAME",env.nodeOsType=<Linux|Windows>,env.apiserverCert=$cert,env.apiserverKey=$key,rbac.install=false
If your cluster has RBAC enabled set rbac.install=true
Output:
NAME: virtual-kubelet
LAST DEPLOYED: Thu Feb 15 13:17:01 2018
NAMESPACE: default
STATUS: DEPLOYED
RESOURCES:
==> v1/Secret
NAME TYPE DATA AGE
virtual-kubelet-virtual-kubelet Opaque 3 1s
==> v1beta1/Deployment
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
virtual-kubelet-virtual-kubelet 1 1 1 0 1s
==> v1/Pod(related)
NAME READY STATUS RESTARTS AGE
virtual-kubelet-virtual-kubelet-7bcf5dc749-6mvgp 0/1 ContainerCreating 0 1s
NOTES:
The virtual kubelet is getting deployed on your cluster.
To verify that virtual kubelet has started, run:
```cli
kubectl --namespace=default get pods -l "app=virtual-kubelet-virtual-kubelet"
To validate that the Virtual Kubelet has been installed, return a list of Kubernetes nodes using the kubectl get nodes command. You should see a node that matches the name given to the ACI connector.
kubectl get nodes
Output:
NAME STATUS ROLES AGE VERSION
virtual-kubelet-myconnector-linux Ready <none> 2m v1.8.3
aks-nodepool1-39289454-0 Ready agent 22h v1.7.7
aks-nodepool1-39289454-1 Ready agent 22h v1.7.7
aks-nodepool1-39289454-2 Ready agent 22h v1.7.7
Create a file named virtual-kubelet-test.yaml
and copy in the following YAML. Replace the nodeName
value with the name given to the virtual kubelet node.
apiVersion: v1
kind: Pod
metadata:
name: helloworld
spec:
containers:
- image: microsoft/aci-helloworld
imagePullPolicy: Always
name: helloworld
resources:
requests:
memory: 1G
cpu: 1
ports:
- containerPort: 80
name: http
protocol: TCP
- containerPort: 443
name: https
dnsPolicy: ClusterFirst
nodeName: virtual-kubelet-myconnector-linux
tolerations:
- key: azure.com/aci
effect: NoSchedule
Notice that Virtual-Kubelet nodes are tainted by default to avoid unexpected pods running on them, i.e. kube-proxy, other virtual-kubelet pods, etc. To schedule a pod to them, you need to add the tolerations to your pod spec:
tolerations:
- key: azure.com/aci
effect: NoSchedule
Run the application with the kubectl create command.
kubectl create -f virtual-kubelet-test.yaml
Use the kubectl get pods command with the -o wide
argument to output a list of pods with the scheduled node.
kubectl get pods -o wide
Notice that the helloworld
pod is running on the virtual-kubelet
node.
NAME READY STATUS RESTARTS AGE IP NODE
aci-helloworld-2559879000-8vmjw 1/1 Running 0 39s 52.179.3.180 virtual-kubelet
To validate that the container is running in an Azure Container Instance, use the az container list Azure CLI command.
az container list -o table
Output:
Name ResourceGroup ProvisioningState Image IP:ports CPU/Memory OsType Location
------------------------------- --------------- ------------------- ------------------------ --------------- --------------- -------- ----------
helloworld-2559879000-8vmjw myResourceGroup Succeeded microsoft/aci-helloworld 52.179.3.180:80 1.0 core/1.5 gb Linux eastus
If you've installed Virtual Kubelet with the Azure cli so you're using the ACI Connector implementation, then you are also able to upgrade the connector to the latest release. Run the following command to upgrade your ACI Connector.
az aks upgrade-connector --resource-group <aks cluster rg> --name <aks cluster name> --connector-name myconnector --os-type linux
You can remove your Virtual Kubelet node by deleting the Helm deployment. Run the following command:
helm delete virtual-kubelet --purge
If you used the ACI Connector installation then use the following command to remove the the ACI Connector from your cluster.
az aks remove-connector --resource-group <aks cluster rg> --name <aks cluster name> --connector-name myconnector --os-type linux