| name | terraform-azurerm-set-diff-analyzer |
| description | Analyze Terraform plan JSON output for AzureRM Provider to distinguish between false-positive diffs (order-only changes in Set-type attributes) and actual resource changes. Use when reviewing terraform plan output for Azure resources like Application Gateway, Load Balancer, Firewall, Front Door, NSG, and other resources with Set-type attributes that cause spurious diffs due to internal ordering changes. |
| license | MIT |
Terraform AzureRM Set Diff Analyzer
A skill to identify "false-positive diffs" in Terraform plans caused by AzureRM Provider's Set-type attributes and distinguish them from actual changes.
When to Use
terraform plan shows many changes, but you only added/removed a single element- Application Gateway, Load Balancer, NSG, etc. show "all elements changed"
- You want to automatically filter false-positive diffs in CI/CD
Background
Terraform's Set type compares by position rather than by key, so when adding or removing elements, all elements appear as "changed". This is a general Terraform issue, but it's particularly noticeable with AzureRM resources that heavily use Set-type attributes like Application Gateway, Load Balancer, and NSG.
These "false-positive diffs" don't actually affect the resources, but they make reviewing terraform plan output difficult.
Prerequisites
If Python is unavailable, install via your package manager (e.g., apt install python3, brew install python3) or from python.org.
Basic Usage
terraform plan -out=plan.tfplan
terraform show -json plan.tfplan > plan.json
python scripts/analyze_plan.py plan.json
Troubleshooting
python: command not found: Use python3 instead, or install PythonModuleNotFoundError: Script uses only standard library; ensure Python 3.8+
Detailed Documentation
scripts/README.md — All options, output formats, exit codes, CI/CD examplesreferences/azurerm_set_attributes.md — Supported resources and attributes
