Overview
Azure Container Registry (ACR) is a secure fully hosted private Docker registry which we will use to both build & store our application container images
Deploying Azure Container Registry
To create a Azure Container Registry instance, pick a name for your ACR, this has to be globally DNS unique (e.g. pick something with your name and the year). We will set this in a Bash variable as we’ll be using it a lot
We’ll re-use the $group and $region variables we set when creating the AKS cluster, so make sure you use the same session/window. If need be, reset the variables to your given values as described at the start of part 1
ACR_NAME="change-this-to-your-unique-acr-name"
az acr create -n $ACR_NAME -g $group -l $region --sku Standard --admin-enabled true
The ACR name can only contain letters and numbers (no dots or dashes, etc), and it’s advised to make it all lowercase
💬 Note. Sept 2018. We will be using a feature called ACR Tasks this is currently in preview but now quite stable.
Configure Kubernetes to use ACR
Get the ACR login password and set it in a Bash variable
ACR_PWD=`az acr credential show -n $ACR_NAME -g $group --query "passwords[0].value" -o tsv`
As a sanity check you can display the value of the password using echo $ACR_PWD
In order for the Kubernetes nodes to authenticate with ACR we will set up a Secret in Kubernetes which holds the login details for our registry. There are other ways to authenticate between AKS and ACR however they are slightly more complex, so we’ll not use them in this lab.
📘 ACR and AKS Authentication
Create a secret called acr-auth with this command:
kubectl create secret docker-registry acr-auth --docker-server $ACR_NAME.azurecr.io --docker-username $ACR_NAME --docker-password $ACR_PWD --docker-email ignore@dummy.com
We will use this secret later on
📕 Kubernetes Glossary. A Secret is a Kubernetes object that holds any sensitive information, such as passwords, connection strings or API keys. Setting up Secrets lets us refer to them by name in our deployments and avoids having sensitive details held in plain text
Build container images with ACR
For this section we will be using a brand new feature of Azure Container Registry called “ACR Tasks”, this allows us to build container images in Azure without need access to a Docker host or having Docker installed locally. It also pushes the resulting images directly into your registry.
We will build our images directly from source. The source of Smilr is held on GitHub in this repository https://github.com/benc-uk/smilr and ACR lets us run the build directly using the URL of a remote repo
To use ACR Tasks to run our Docker build task in Azure, we call the az acr build sub-command. The first image we’ll build is for the Smilr data API component, the source Dockerfile is in the node/data-api sub-directory and we’ll tag the resulting image smilr/data-api
az acr build --registry $ACR_NAME -g $group --file node/data-api/Dockerfile --image smilr/data-api https://github.com/benc-uk/smilr.git
💬 Note. If you are familiar with the Docker command line and the docker build command you notice some similarity in syntax and approach
💬 Note. If the CLI times out with a “no more logs” message you can still view the build logs by running az acr task logs -r $ACR_NAME -g $group to check on the progress
That should take about a minute or two to run. After that we’ll build the frontend, the command will be very similar just with a different source file image tag
az acr build --registry $ACR_NAME -g $group --file node/frontend/Dockerfile --image smilr/frontend https://github.com/benc-uk/smilr.git
This will take slightly longer but should complete in 3-5 minutes
If you want to double check the images have been built and stored in your registry you can run
az acr repository list -g $group --name $ACR_NAME -o table
End of Module 2
We now have the application images we need built & stored in a private registry. We also have the authorization in place to get AKS to pull/run our images, so we can proceed to look at deploying our microservices into Kubernetes
🡸 Module 1: Deploying Kubernetes 🡺 Module 3: Deploying the Data Layer
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