start-vm.sh

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Purpose

Start one or more Azure VMs and optionally wait until they are running.

Location

cloud/azure/vm/start-vm.sh

Preconditions

  • Required tools: bash, az, awk, date, sleep
  • Required permissions: Microsoft.Compute/virtualMachines/start/action, read access for instance view
  • Required environment variables: none

Arguments

Flag Required Default Description
--resource-group NAME Yes N/A Resource group containing VMs
--name NAME Cond. none VM name (repeatable)
--names CSV Cond. none Comma-separated VM names
--subscription ID No az default Subscription override
--wait No true Wait for running state
--no-wait No false Return immediately
--timeout SEC No 900 Wait timeout
--poll-interval SEC No 10 Poll interval
--dry-run No false Print commands only

Scenarios

  • Happy path: start application VMs before a deployment window.
  • Common operational path: start a batch of VMs from CSV list.
  • Failure path: wrong resource group or missing start permission.
  • Recovery/rollback path: correct context and retry selected VMs.

Usage

cloud/azure/vm/start-vm.sh --resource-group rg-app-prod --name vm-app-01
cloud/azure/vm/start-vm.sh --resource-group rg-app-prod --names vm-app-01,vm-app-02 --no-wait

Behavior

  • Main execution flow:
  • validates required scope and target names
  • runs az vm start per VM
  • optionally polls instance power state until VM running
  • Idempotency notes: repeated starts are generally safe.
  • Side effects: VM power state transitions to running.

Output

  • Standard output format: timestamped logs on stderr.
  • Exit codes:
  • 0 success
  • 2 validation errors
  • non-zero on Azure CLI/API or timeout failures

Failure Modes

  • Common errors and likely causes:
  • invalid VM/resource-group pairing
  • denied start permissions
  • wait timeout during platform delays
  • Recovery and rollback steps:
  • verify resource-group and subscription
  • verify role assignment for start action
  • rerun with higher timeout

Security Notes

  • Secret handling: no secret values accepted as flags.
  • Least-privilege requirements: start + read instance-view permissions only.
  • Audit/logging expectations: VM start operations should map to approved changes.

Testing

  • Unit tests:
  • list parsing and wait option handling
  • Integration tests:
  • start stopped test VMs with wait/no-wait
  • Manual verification:
  • inspect state with az vm get-instance-view
list-vms.sh stop-vm.sh