Infrastructure as a Service in Azure

To leverage Azure as Infrastructure as a service, we have to think in terms following capabilities

• Compute
  • Available through Virtual Machines
• Network
  • Available through Virtual Network
• Storage
  • Available through Storage Account

Virtual Network

• Equivalent of a network in Azure
• It contains an IP range
• Can be subdivided into multiple Logical Subnets
• A default Subnet is created with a subset of the IP range when a VNET is created
• Additional subnets can be added and associated with different subsets of the IP range.

Virtual Machine

• Equivalent of a physical machine in Azure
• Hosted inside a VNET
• Every machine contains a Network Interface through which it connects with VNET

Storage

• Virtual machine uses Virtual Hard drives to store OS and temp data
• Virtual Hard drives can be stored in blobs in a Storage account
• VHDs are also used for storing the images
• Temp data gets deleted when restarting a Virtual machine
• Additional data disks can also be added to store Application data
• Disks can be configured as managed or unmanaged Disks
  • For unmanage disks, we need to manage the storage account
  • Managed disks are managed by Microsoft and are commended for 99.999% availability

Network Interface

• IP Addresses are attached to a VNET interface that is linked to VM
• Private IPs are used for communicating between VMs
• Public IPs are used for external access
• When a virtual machine is restarted, it will get a new Public IP address

Network Security Group

• A subnet can be secured with a Network Security group
• NSG contains rules for ingress (incoming network traffic) and egress (outgoing network traffic)