Why Containers?
Applications are increasingly built as microservices — small, independently deployable components. Containers make this possible by packaging apps and dependencies into lightweight, portable units.
Azure supports containers in multiple ways:
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Running single containers (Azure Container Instances).
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Running orchestrated clusters (AKS).
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Hosting containerized apps on App Services.
As a Solution Architect, you must know when to use containers vs VMs vs PaaS and how AKS fits into enterprise designs.
Azure Container Options
1. Azure Container Instances (ACI)
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Fast, serverless container execution.
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Best for burst workloads, batch jobs, or test environments.
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Not meant for long-running production apps.
2. Azure Kubernetes Service (AKS)
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Fully managed Kubernetes service.
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Orchestrates deployment, scaling, and management of containers.
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Integrates with monitoring, RBAC, networking, and CI/CD.
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Supports hybrid and multi-cloud scenarios with Kubernetes portability.
3. Containers in App Service
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Run containerized apps with App Service features (scaling, SSL, custom domains).
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Best for single apps where orchestration isn’t needed.
AKS Core Design Features
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Cluster Management
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Control plane managed by Azure.
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Nodes (VMs) managed by you or auto-scaled.
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Scaling
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Horizontal Pod Autoscaler for workload scaling.
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Cluster Autoscaler for scaling nodes.
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Networking
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Integrates with Azure CNI (pods get VNET IPs).
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Supports service meshes (Istio, Linkerd).
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Security
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RBAC integrated with Entra ID (Azure AD).
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Secrets stored in Key Vault.
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Network policies for pod-level isolation.
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CI/CD Integration
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Works with Azure DevOps, GitHub Actions, Helm charts.
Example Enterprise Scenario
A fintech company wants to:
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Deploy microservices-based payment system.
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Scale workloads automatically during peak transactions.
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Ensure portability across Azure and on-prem.
Correct design:
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Use AKS for orchestrating microservices.
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Enable Cluster Autoscaler for scaling nodes.
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Secure secrets with Key Vault integration.
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Use Front Door or App Gateway with Ingress Controller for external access.
Confusion Buster
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ACI vs AKS
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ACI = single/burst containers, serverless.
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AKS = orchestrated production clusters.
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App Service Containers vs AKS
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App Service = run single app in a container.
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AKS = run distributed microservices.
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AKS vs VMSS
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AKS = manages containerized apps.
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VMSS = manages scaling of raw VMs.
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Exam Tips
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“Which service for lightweight, serverless container execution?” → ACI.
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“Which service orchestrates containerized workloads in production?” → AKS.
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“Which is best for multi-service app requiring CI/CD and scaling?” → AKS.
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“Company wants container portability across clouds.” → AKS (Kubernetes).
What to Expect in the Exam
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Direct Q: “Which service provides fully managed Kubernetes?” → AKS.
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Scenario Q: “Company needs microservices architecture with CI/CD integration.” → AKS.
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Scenario Q: “Company needs quick one-off container job.” → ACI.
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Trick Q: “App Service Containers can replace AKS for orchestrating 50 microservices.” → False.