label-cloud-resources

name	label-cloud-resources
description	Add default labels to cloud providers using default_tags/default_labels blocks. Use when reviewing Terraform PRs that need consistent provider-level labeling.
disable-model-invocation	false
argument-hint	<label_name:label_value> [--dry-run] [--comment]
allowed-tools	Bash, Grep, Glob, Read, Edit
scope	["terraform"]

Cloud Resource Default Labeling

Add standardized labels to cloud providers using default_tags (AWS) or default_labels (GCP) in a PR. This approach automatically applies labels to all resources managed by the provider without needing to modify individual resources.

Arguments

• label_name:label_value (required): The label to add in the format name:value (e.g., ct_owner:team-platform, environment:production)
• --dry-run (optional): Preview the changes without applying them
• --comment (optional): Post a summary comment on the PR with the labeling results

Process

1. Validate Arguments

Parse the label argument and ensure it follows the label_name:label_value format.

# Extract label name and value
LABEL_INPUT="$ARGUMENTS"
LABEL_NAME=$(echo "$LABEL_INPUT" | cut -d':' -f1)
LABEL_VALUE=$(echo "$LABEL_INPUT" | cut -d':' -f2)

2. Identify Changed Provider Files

Find Terraform files that were changed in the current PR and contain provider blocks:

# Get files changed in current PR, filter for .tf files
CHANGED_TF_FILES=$(gh pr view --json files | jq -r '.files[].path' | grep '\.tf$')

# Check which of these files contain provider blocks
PROVIDER_FILES=""
for file in $CHANGED_TF_FILES; do
  if grep -q "provider \"" "$file"; then
    PROVIDER_FILES="$PROVIDER_FILES $file"
  fi
done

Only process provider blocks in files that are part of the current PR changes.

3. Locate Provider Blocks in Affected Directories

For each provider file found in directories with changes, locate provider configurations for:

• AWS: provider "aws" blocks
• GCP: provider "google" blocks

# Example: Check for AWS providers in directories with changes
for file in $PROVIDER_FILES; do
  if grep -q 'provider "aws"' "$file"; then
    echo "Found AWS provider in $file (directory: $(dirname $file))"
  fi
done

4. Apply Default Labels to Provider Files in Modified Directories

Add or update the default labeling configuration for each provider found in directories that contain PR changes:

AWS Provider:

provider "aws" {
  # existing configuration...

  default_tags {
    tags = {
      # existing tags...
      "${LABEL_NAME}" = "${LABEL_VALUE}"
    }
  }
}

GCP Provider:

provider "google" {
  # existing configuration...

  default_labels = {
    # existing labels...
    "${LABEL_NAME}" = "${LABEL_VALUE}"
  }
}

5. Handle Edge Cases

• Missing default_tags/default_labels block: Create the block if it doesn't exist in provider files within modified directories
• Existing label: Update the value if the label already exists
• Multiple provider instances: Apply to all instances of the same provider in directories with changes
• Provider aliases: Handle aliased providers appropriately
• No provider files in modified directories: Skip labeling if no provider blocks are found in directories with changes
• Multiple directories: Apply labeling to provider files in all directories that contain any file changes

Output Format

## Terraform Provider Labeling Results

**Label Applied**: `${LABEL_NAME}:${LABEL_VALUE}`

### Modified Files (from PR changes):

- `providers.tf` (AWS provider updated)
- `modules/networking/main.tf` (GCP provider updated)

### Providers Updated:

- `aws` (default_tags block in providers.tf)
- `google` (default_labels block in modules/networking/main.tf)

### Impact:

- **AWS resources** managed by providers.tf will inherit the `${LABEL_NAME}:${LABEL_VALUE}` tag
- **GCP resources** managed by modules/networking/main.tf will inherit the `${LABEL_NAME}:${LABEL_VALUE}` label

### Summary:

- **Files analyzed**: Only files changed in this PR
- **Provider files modified**: 2
- **Providers affected**: AWS, GCP
- **Scope**: Only resources managed by providers in changed files

Guidelines

Supported Providers

Focus on major cloud providers and their default labeling conventions:

• AWS: default_tags { tags = {} } - applies to all AWS resources automatically
• GCP: default_labels = {} - applies to all GCP resources automatically

Provider Detection

Look for provider blocks only in files changed by the current PR:

• First get PR file changes: gh pr view --json files
• Filter for .tf files in the change set
• Search for provider "..." blocks only in those files
• Focus on commonly changed files: providers.tf, main.tf, versions.tf

Label Validation

• Ensure label names follow provider naming conventions
• Convert label names to lowercase with underscores for GCP
• Validate label values don't exceed provider limits
• Escape special characters appropriately

Best Practices

• Use provider-level labeling over individual resource labeling
• Preserve existing default_tags/default_labels
• Use consistent formatting within provider blocks
• Add labels in alphabetical order for consistency
• Consider label inheritance and conflicts with resource-specific tags

Error Handling

• Handle providers without existing default labeling blocks in changed files
• Warn about provider-specific limitations
• Handle malformed Terraform syntax gracefully in changed files
• Provide clear error messages for invalid label formats
• Skip unsupported provider types
• No provider changes: Inform user if no provider blocks found in PR changes

Examples

Basic Usage

/label-cloud-resources ct_owner:team-platform

With Dry Run

/label-cloud-resources environment:staging --dry-run

With PR Comment

/label-cloud-resources cost-center:engineering --comment

Multiple Labels (run separately)

/label-cloud-resources ct_owner:team-backend
/label-cloud-resources environment:production
/label-cloud-resources project:api-gateway