📦 Container Registry & Images
We will deploy & use a private registry to hold the application container images. This is not strictly necessary as we could pull the images directly from the public, however using a private registry is a more realistic approach.
Azure Container Registry is what we will be using.
🚀 ACR Deployment
Deploying a new ACR is very simple:
az acr create --name $ACR_NAME --resource-group $RES_GROUP \
--sku Standard \
--admin-enabled true
📝 NOTE: When you pick a name for the resource with $ACR_NAME, this has to be globally unique, and not contain no underscores, dots, or hyphens.
📥 Importing Images
For the sake of speed and maintaining the focus on Kubernetes we will import pre-built images from another public registry (GitHub Container Registry), rather than build them from source.
We will cover what the application does and what these containers are for in the next section, for now we can just import them.
To do so we use the az acr import command:
# Import application frontend container image
az acr import --name $ACR_NAME --resource-group $RES_GROUP \
--source ghcr.io/benc-uk/smilr/frontend:stable \
--image smilr/frontend:stable
# Import application data API container image
az acr import --name $ACR_NAME --resource-group $RES_GROUP \
--source ghcr.io/benc-uk/smilr/data-api:stable \
--image smilr/data-api:stable
If you wish to check and see imported images, you can go over to the ACR resource in the Azure portal, and into the ‘Repositories’ section.
📝 NOTE: we are not using the tag
latestwhich is a common mistake when working with Kubernetes and containers in general.
🔌 Connect K3s to ACR
Kuberenetes requires a way to authenticate and access images stored in private registries. There are
a number of ways to enable Kubernetes to pull images from a private registry, however K3S provides a
simple way to configure this through the registries.yaml. The downside is this requires you to
manually add the file to your device/VM.
On your VM create the registries.yaml with the following content:
📝 NOTE: The password is retrieved with Azure CLI, if you don’t have Azure CLI on the VM, you can just retrieve your ACR password from the portal and replace that section your ACR password
# Copy the ACR name from the .env file created earlier or from Azure
ACR_NAME=<your_acr_value>
cat <<EOT > /etc/rancher/k3s/registries.yaml
configs:
"$ACR_NAME.azurecr.io":
auth:
username: $ACR_NAME
password: $(az acr credential show --name $ACR_NAME --query "passwords[0].value" -o tsv)
EOT
# Verify the file was created with the right values
cat /etc/rancher/k3s/registries.yaml
# Restart K3s for the change to take effect
sudo systemctl restart k3s;
To read more about how
registries.yamlworks, you can checkout Rancher Docs: Private Registry Configuration.