We recently added support in Habitat Builder for Azure Container Registry (ACR). With this integration you can export to Azure Container Registry as part of your build job and use those containers inside AKS.
In this walkthrough we’ll show you how to setup the ACR integration in Habitat Builder and how to configure Azure Kubernetes Services to run the a sample Habitat application.
What are the Azure Container Registry and Azure Kubernetes Service ?
Azure Container Registry is a managed Docker container registry service used for storing private Docker container images. It’s a fully managed Azure resource and gives you local, network-close storage of your container images when deploying to Azure.
Azure Kubernetes Service (AKS) is a fully managed hosted Kubernetes environment that makes it quick and easy to deploy and manage containerized applications without container orchestration expertise. It also eliminates the burden of ongoing operations and maintenance by provisioning, upgrading, and scaling resources on demand, without taking your applications offline.
Using both of them together allows you to quickly stand up a Kubernetes cluster along with a private repository to hold the containers.
Walkthrough
We’re going to use the az and kubectl command-line tools throughout this example. If you’re using the Azure Cloud Shell both of these tools are already installed.
If you choose to install and use the CLI locally see Install Azure CLI. Once you have the Azure CLI installed it can download kubectl, the Kubernetes command line client, to manage the cluster:
Azure CLI
$ az aks install-cli
All the code used in this example is available on GitHub at https://github.com/jamesc/azure-habitat-example.
Create AKS Cluster and ACR registry
First off we need to create a new cluster and registry. You can use the following script that will:
- Create a Azure Kubernetes Service Cluster
- Create a Azure Container Registry
- Grant access to the Registry for the service principal associated with the cluster
- Create a new Service Principal to be used by Habitat Builder to publish to the registry
The credentials for the Service Principal will be outputted by the script. These will be used in the next step to configure Habitat Builder.
setup-aks-acr.sh
#!/bin/sh # # Change these for your account # RESOURCE_GROUP="habitat-aks-demo" AKS_CLUSTER_NAME="aks-demo" ACR_NAME="habitatregistry" BLDR_PRINCIPAL_PASSWORD="ThisIsVeryStrongPassword" # # No Need to change these # BLDR_PRINCIPAL_NAME="habitat-acr-registry" AKS_NODE_COUNT=1 ACR_SKU="Basic" # # Setup AKS # az group create --name $RESOURCE_GROUP --location eastus az aks create --resource-group $RESOURCE_GROUP --name $AKS_CLUSTER_NAME --node-count $AKS_NODE_COUNT --generate-ssh-keys az aks get-credentials --resource-group $RESOURCE_GROUP --name $AKS_CLUSTER_NAME # # Setup ACR # az acr create --resource-group $RESOURCE_GROUP --name $ACR_NAME --sku $ACR_SKU # # Grant Reader access to ACR from AKS # CLIENT_ID=$(az aks show --resource-group $RESOURCE_GROUP --name $AKS_CLUSTER_NAME --query "servicePrincipalProfile.clientId" --output tsv) ACR_ID=$(az acr show --name $ACR_NAME --resource-group $RESOURCE_GROUP --query "id" --output tsv) az role assignment create --assignee $CLIENT_ID --role Reader --scope $ACR_ID # Create Service Principal for Habitat Builder az ad sp create-for-rbac --scopes $ACR_ID --role Owner --password "$BLDR_PRINCIPAL_PASSWORD" --name $BLDR_PRINCIPAL_NAME BLDR_ID=$(az ad sp list --display-name $BLDR_PRINCIPAL_NAME --query "[].appId" --output tsv) echo "ID/Password for Habitat Builder Principal:" echo "ID : $BLDR_ID" echo "Password : $BLDR_PRINCIPAL_PASSWORD"
Command Output
$ ./setup-aks-acr.sh Retrying role assignment creation: 1/36 Retrying role assignment creation: 2/36 ... ... ... Configuration Details for Habitat Builder: Server URL : habitatregistry.azurecr.io Service Principal ID : 1449e154-69d5-4f44-806f-7098b8f653d6 Service Principal Password : ThisIsVeryStrongPassword
Configure builder to export to the registry
Now that you have setup the registry you need to use the Habitat Builder user interface to add the Azure Container Registry to your origin. This uses the configuration details outputted by the setup script.
Connect your packages to the registry
The final step to be carried out in the Habitat Builder user interface is to connect a plan file (we’re using the wordpress and mysql plans from the GitHub repository) and configure it to export it to our container registry. First we do this for the wordpress package which has its plan file at wordpress/plan.sh.
You can then trigger a new build of the package and follow progress in the live build output window of Habitat Builder. You’ll see a container being built and pushed to the registry.
Repeat these steps for the mysql package with a plan file at mysql/plan.sh. You can verify that the packages have been pushed using the az command-line.
Verify Registry Contents
$ az acr repository list --name habitatregistry [ "habitat/mysql", "habitat/wordpress" ]
Deploy the Habitat Operator to Kubernetes
The Habitat Operator for Kubernetes is the recommended way to integrate Habitat and Kubernetes into a unified whole. It leverages the Kubernetes API to unify communication between your Kubernetes clusters and Habitat Builder as it builds and manages your applications, and enables you to use both kubectl and the hab cli and keep all of your components in sync.
The following Kubernetes Deployment object installs the Habitat Operator in our cluster.
habitat-operator.yml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: habitat-operator
spec:
replicas: 1
template:
metadata:
labels:
name: habitat-operator
spec:
containers:
- name: habitat-operator
image: habitat/habitat-operator:v0.6.1
Verify deployment of Habitat Operator
$ kubectl apply -f habitat-operator.yml deployment.extensions "habitat-operator" created $ kubectl get pods NAME READY STATUS RESTARTS AGE habitat-operator-854d7dc494-jnf7n 1/1 Running 0 10s
Deploy your application to AKS
Finally we’re ready to deploy our application. Our example WordPress application consists of two components – the WordPress server and the backend MySQL database. The following Kubernetes configuration will:
- Create a Kubernetes secret with our MySQL credentials
- Deploy two Habitat packages (
habitat/wordpressandhabitat/mysql) from ACR - Setup a Kubernetes load balancer to export our wordpress application port.
deploy-wordpress.yml
apiVersion: v1
kind: Secret
metadata:
name: mysql-user-toml
type: Opaque
data:
# Each item needs to be base64-encoded.
# Plain text content:
# app_username="wordpress"
# app_password="ThisIsSecret"
# bind='0.0.0.0'
user.toml: YXBwX3VzZXJuYW1lPSJ3b3JkcHJlc3MiCmFwcF9wYXNzd29yZD0iVGhpc0lzU2VjcmV0IgpiaW5kPScwLjAuMC4wJwo=
---
apiVersion: habitat.sh/v1beta1
kind: Habitat
metadata:
name: wordpress-db
customVersion: v1beta2
spec:
v1beta2:
image: habitatregistry.azurecr.io/habitat/mysql:latest
count: 1
service:
name: mysql
topology: standalone
configSecretName: mysql-user-toml
---
apiVersion: habitat.sh/v1beta1
kind: Habitat
metadata:
name: wordpress-app
customVersion: v1beta2
spec:
v1beta2:
image: habitatregistry.azurecr.io/habitat/wordpress:latest
count: 1
service:
name: wordpress
topology: standalone
bind:
- name: database
service: mysql
group: default
---
apiVersion: v1
kind: Service
metadata:
name: wordpress-lb
spec:
type: LoadBalancer
ports:
- name: web
port: 80
targetPort: 80
selector:
habitat-name: wordpress-app
Again we deploy this using kubectl apply. After a few minutes both pods should be running:
Verify deployment of the WordPress application and database pods
$ kubectl apply -f deploy-wordpress.yml secret "mysql-user-toml" created habitat.habitat.sh "wordpress-db" created habitat.habitat.sh "wordpress-app" created service "wordpress-lb" created $ kubectl get pods NAME READY STATUS RESTARTS AGE habitat-operator-854d7dc494-jnf7n 1/1 Running 0 2m wordpress-app-0 1/1 Running 0 2m wordpress-db-0 1/1 Running 0 2m
We can retrieve the external IP of the load balancer from Kubernetes:
Check for load balancer details
$ $ kubectl get service wordpress-lb --watch NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE wordpress-lb LoadBalancer 10.0.91.26 168.62.36.237 80:32336/TCP 8m
And finally we can check that WordPress is up and running on the external IP.
Summary
In this walkthrough you saw how to setup Habitat Builder, Azure Container Registry and Azure Container Services,creating a complete continuous deployment pipeline for your application. This pattern can applied to any application packaged with Habitat creating a standard mechanism for you to run all your applications.
Got questions?
- Ask and answer questions on the Habitat forums
- Chat with the Habitat Community on Slack
- Learn more about Habitat
