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Advanced use of az-cli in bash

This page demonstrates advanced Bash and Zsh scripting techniques for managing Azure resources with az-cli. All examples assume you have Azure CLI installed and authenticated.

Bash Examples

If-Then-Else: Check if Variable is Null

if [ -n "$resourceGroup" ]; then
   echo "$resourceGroup"
else
   resourceGroup="msdocs-learn-bash-$RANDOM"
fi

If-Then: Create or Delete a Resource Group

Create if not exists:

if [ "$(az group exists --name "$resourceGroup")" = false ]; then 
   az group create --name "$resourceGroup" --location "$location"
else
   echo "$resourceGroup already exists."
fi

Delete if exists:

if [ "$(az group exists --name "$resourceGroup")" = true ]; then 
   az group delete --name "$resourceGroup" -y # --no-wait
else
   echo "The $resourceGroup resource group does not exist."
fi

Grep: Create Resource Group if Not Exists

az group list --output tsv | grep -q "$resourceGroup" || az group create --name "$resourceGroup" --location "$location"

Case Statement: Create Resource Group if Not Exists

var=$(az group list --query "[?name=='$resourceGroup'].name" --output tsv)
case "$resourceGroup" in
  $var)
    echo "The $resourceGroup resource group already exists." ;;
  *)
    az group create --name "$resourceGroup" --location "$location" ;;
esac

Zsh Examples & Configuration

Zsh syntax is nearly identical to Bash for these use cases. Ensure variables are quoted and use parameter expansion for null checks.

If-Then-Else: Check if Variable is Null

if [[ -n "$resourceGroup" ]]; then
  echo "$resourceGroup"
else
  resourceGroup="msdocs-learn-zsh-$RANDOM"
fi

If-Then: Create or Delete a Resource Group

Create if not exists:

if [[ "$(az group exists --name "$resourceGroup")" == false ]]; then
  az group create --name "$resourceGroup" --location "$location"
else
  echo "$resourceGroup already exists."
fi

Delete if exists:

if [[ "$(az group exists --name "$resourceGroup")" == true ]]; then
  az group delete --name "$resourceGroup" -y # --no-wait
else
  echo "The $resourceGroup resource group does not exist."
fi

Grep: Create Resource Group if Not Exists

az group list --output tsv | grep -q "$resourceGroup" || az group create --name "$resourceGroup" --location "$location"

Case Statement: Create Resource Group if Not Exists

var=$(az group list --query "[?name=='$resourceGroup'].name" --output tsv)
case "$resourceGroup" in
  $var)
    echo "The $resourceGroup resource group already exists." ;;
  *)
    az group create --name "$resourceGroup" --location "$location" ;;
esac

Best Practices

  • Always quote variables to prevent word splitting and globbing.
  • Use -n/-z for null checks in Bash/Zsh.
  • Use --output tsv for scripting to simplify parsing.
  • Prefer [[ ... ]] for conditionals in Zsh.
  • Use $RANDOM for unique resource group names in scripts.

References