/azure-cloud-migrate

Kubernetes to Azure Container Apps - Deployment Guide

Prerequisites

Azure CLI 2.53.0+, kubectl, Docker, Azure subscription, ACR, Key Vault, Log Analytics

Phase 1: Export Kubernetes Resources

kubectl get deployments,services,ingress -n <namespace> -o wide
kubectl get configmaps,secrets -n <namespace>

Export Script

#!/bin/bash
set -euo pipefail
NAMESPACE="${K8S_NAMESPACE:-<namespace>}"
OUTPUT_DIR="${OUTPUT_DIR:-k8s-export}"
mkdir -p "$OUTPUT_DIR"
kubectl get deploy,svc,ingress,configmap,secret -n "$NAMESPACE" -o yaml > "$OUTPUT_DIR/all-resources.yaml"
for deploy in $(kubectl get deploy -n "$NAMESPACE" -o jsonpath='{.items[*].metadata.name}'); do
  kubectl get deployment "$deploy" -n "$NAMESPACE" -o yaml > "$OUTPUT_DIR/deploy-${deploy}.yaml"
done

Phase 2: Assess Compatibility

Load assessment-guide.md. Check: StatefulSets, DaemonSets, CRDs, resource limits (>4 vCPU/>8 GiB), PVCs, NetworkPolicies.

Phase 3: Migrate Images

⚠️ Warning: Azure Container Apps only runs linux/amd64 images. If you build on Apple Silicon or another ARM host, use docker buildx build --platform linux/amd64 or az acr build (which builds amd64 by default). Verify with docker inspect <image> --format '{{.Architecture}}'.

Bash

#!/bin/bash
set -euo pipefail
ACR_NAME="${ACR_NAME:-<acr>}"
SOURCE_REGISTRY="${SOURCE_REGISTRY:-<registry>}"
az acr login --name "$ACR_NAME"
az acr import --name "$ACR_NAME" --source "${SOURCE_REGISTRY}/app:v1.0" --image app:v1.0

PowerShell

$ACR_NAME = if ($env:ACR_NAME) { $env:ACR_NAME } else { "<acr>" }
$SOURCE_REGISTRY = if ($env:SOURCE_REGISTRY) { $env:SOURCE_REGISTRY } else { "<registry>" }
az acr login --name $ACR_NAME
az acr import --name $ACR_NAME --source "${SOURCE_REGISTRY}/app:v1.0" --image app:v1.0

Phase 4: Infrastructure

Bash

az group create --name myapp-rg --location eastus
az monitor log-analytics workspace create --resource-group myapp-rg --workspace-name myapp-logs --location eastus
LOG_ID=$(az monitor log-analytics workspace show --resource-group myapp-rg --workspace-name myapp-logs --query customerId -o tsv)
LOG_KEY=$(az monitor log-analytics workspace get-shared-keys --resource-group myapp-rg --workspace-name myapp-logs --query primarySharedKey -o tsv)
az containerapp env create --name myapp-env --resource-group myapp-rg --location eastus --logs-workspace-id "$LOG_ID" --logs-workspace-key "$LOG_KEY"

PowerShell

az group create --name myapp-rg --location eastus
az monitor log-analytics workspace create --resource-group myapp-rg --workspace-name myapp-logs --location eastus
$LOG_ID = az monitor log-analytics workspace show --resource-group myapp-rg --workspace-name myapp-logs --query customerId -o tsv
$LOG_KEY = az monitor log-analytics workspace get-shared-keys --resource-group myapp-rg --workspace-name myapp-logs --query primarySharedKey -o tsv
az containerapp env create --name myapp-env --resource-group myapp-rg --location eastus --logs-workspace-id $LOG_ID --logs-workspace-key $LOG_KEY

VNet: For VNet integration, create VNet first, get subnet ID, then use --infrastructure-subnet-resource-id with env create.

Phase 5: Secrets

Tip: Prefer piping decoded secret values directly to az keyvault secret set --value to avoid writing sensitive data to disk.

Bash

ACR_NAME="${ACR_NAME:-<acr>}"

# Create Key Vault and migrate secrets (pipe directly — no temp file)
az keyvault create --name myapp-kv --resource-group myapp-rg --location eastus
az keyvault secret set --vault-name myapp-kv --name password --value "$(kubectl get secret mysecret -n <namespace> -o jsonpath='{.data.password}' | base64 -d)"

# Create managed identity and grant permissions
az identity create --name myapp-id --resource-group myapp-rg --location eastus
IDENTITY_ID=$(az identity show --name myapp-id --resource-group myapp-rg --query id -o tsv)
PRINCIPAL_ID=$(az identity show --name myapp-id --resource-group myapp-rg --query principalId -o tsv)
KV_ID=$(az keyvault show --name myapp-kv --resource-group myapp-rg --query id -o tsv)
az role assignment create --assignee "$PRINCIPAL_ID" --role "Key Vault Secrets User" --scope "$KV_ID"
ACR_ID=$(az acr show --name "$ACR_NAME" --query id -o tsv)
az role assignment create --assignee "$PRINCIPAL_ID" --role AcrPull --scope "$ACR_ID"

PowerShell

$ACR_NAME = if ($env:ACR_NAME) { $env:ACR_NAME } else { "<acr>" }

# Create Key Vault and migrate secrets (pass directly — no temp file, no BOM issues)
az keyvault create --name myapp-kv --resource-group myapp-rg --location eastus
$secretValue = kubectl get secret mysecret -n <namespace> -o jsonpath='{.data.password}'
$decodedSecretValue = [System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String($secretValue))
az keyvault secret set --vault-name myapp-kv --name password --value $decodedSecretValue
Remove-Variable -Name decodedSecretValue, secretValue -ErrorAction SilentlyContinue

# Create managed identity and grant permissions
az identity create --name myapp-id --resource-group myapp-rg --location eastus
$IDENTITY_ID = az identity show --name myapp-id --resource-group myapp-rg --query id -o tsv
$PRINCIPAL_ID = az identity show --name myapp-id --resource-group myapp-rg --query principalId -o tsv
$KV_ID = az keyvault show --name myapp-kv --resource-group myapp-rg --query id -o tsv
az role assignment create --assignee $PRINCIPAL_ID --role "Key Vault Secrets User" --scope $KV_ID
$ACR_ID = az acr show --name $ACR_NAME --query id -o tsv
az role assignment create --assignee $PRINCIPAL_ID --role AcrPull --scope $ACR_ID

Phase 6: Deploy

⚠️ Warning: Service Discovery Changes — In Kubernetes, pods reach other services by short DNS name (e.g., http://order-service:3001). In Container Apps, internal services use HTTPS FQDNs (e.g., https://order-service.internal.<env-domain>). Audit application code for hardcoded Kubernetes hostnames/ports in HTTP clients, proxy logic, or connection strings — these must be replaced with env-var-driven URLs that point to the Container Apps internal FQDN.

Mapping: spec.containers[].image → template.containers[].image; spec.containers[].ports[].containerPort → ingress.targetPort; spec.replicas → scale.minReplicas. Service types: ClusterIP → external: false; LoadBalancer/NodePort → external: true.

# Get Key Vault secret URI and deploy
SECRET_URI=$(az keyvault secret show --vault-name myapp-kv --name password --query id -o tsv)
az containerapp create --name my-app --resource-group myapp-rg --environment myapp-env \
  --image $ACR_NAME.azurecr.io/app:v1.0 --target-port 8080 --ingress external \
  --cpu 1.0 --memory 2Gi --min-replicas 2 --max-replicas 10 \
  --user-assigned $IDENTITY_ID --registry-identity $IDENTITY_ID --registry-server $ACR_NAME.azurecr.io \
  --secrets password=keyvaultref:$SECRET_URI,identityref:$IDENTITY_ID \
  --env-vars ENV=prod DB_PASSWORD=secretref:password \
  --scale-rule-name http --scale-rule-type http --scale-rule-http-concurrency 80

$SECRET_URI = az keyvault secret show --vault-name myapp-kv --name password --query id -o tsv
az containerapp create --name my-app --resource-group myapp-rg --environment myapp-env `
  --image "$ACR_NAME.azurecr.io/app:v1.0" --target-port 8080 --ingress external `
  --cpu 1.0 --memory 2Gi --min-replicas 2 --max-replicas 10 `
  --user-assigned $IDENTITY_ID --registry-identity $IDENTITY_ID --registry-server "$ACR_NAME.azurecr.io" `
  --secrets "password=keyvaultref:$SECRET_URI,identityref:$IDENTITY_ID" `
  --env-vars ENV=prod DB_PASSWORD=secretref:password `
  --scale-rule-name http --scale-rule-type http --scale-rule-http-concurrency 80

Phase 7: Validation

# Get app FQDN and test
FQDN=$(az containerapp show --name my-app --resource-group myapp-rg --query properties.configuration.ingress.fqdn -o tsv)
echo "App URL: https://$FQDN"
curl https://$FQDN/health

# View logs
az containerapp logs show --name my-app --resource-group myapp-rg --follow

$FQDN = az containerapp show --name my-app --resource-group myapp-rg --query properties.configuration.ingress.fqdn -o tsv
Write-Host "App URL: https://$FQDN"
Invoke-WebRequest -Uri "https://$FQDN/health" -Method Head

# View logs
az containerapp logs show --name my-app --resource-group myapp-rg --follow

Troubleshooting