DevOps Maintainability Checker

Verify infrastructure code follows maintainable patterns.

Maintainability Checklist

Check Good Bad

Resource naming Consistent ${project}-${env}-${type}

Random or inconsistent

Variable naming Descriptive with defaults Cryptic, no descriptions

Code formatting tofu fmt passes Inconsistent indentation

DRY principle Locals for repeated values Hardcoded values repeated

Version constraints Pinned ~> X.Y

Unpinned or exact versions

Verification Commands

Format check

tofu fmt -check -recursive 2>&1 || echo "FAIL: Needs formatting"

Variable descriptions

grep -L "description" variables.tf && echo "WARN: Variables missing descriptions"

Locals usage (should have some)

grep -c "local." *.tf | awk -F: '$2 < 3 {print "WARN: Underusing locals in "$1}'

Hardcoded values (potential DRY violations)

grep -E '^\s+(region|zone|size)\s*=\s*"[^$]' *.tf

Provider version constraints

grep -E "version\s*=\s*"[0-9]" *.tf | grep -v "~>" && echo "WARN: Exact versions, use ~>"

Naming Conventions

Resource Names:

GOOD

resource "aws_instance" "web" { tags = { Name = "${var.project}-${var.environment}-web" } }

BAD

resource "aws_instance" "instance1" { tags = { Name = "my-server" } }

Variable Names:

GOOD

variable "database_instance_class" { description = "RDS instance class for the database" type = string default = "db.t3.micro" }

BAD

variable "db_class" { type = string }

DRY Patterns

Use Locals:

locals { common_tags = { Project = var.project Environment = var.environment ManagedBy = "terraform" } name_prefix = "${var.project}-${var.environment}" }

resource "aws_instance" "web" { tags = merge(local.common_tags, { Name = "${local.name_prefix}-web" }) }

Avoid Repetition:

BAD - hardcoded everywhere

resource "aws_instance" "web" { tags = { Project = "myapp", Environment = "prod" } } resource "aws_instance" "api" { tags = { Project = "myapp", Environment = "prod" } }

GOOD - use locals

resource "aws_instance" "web" { tags = local.common_tags }

Version Constraints

GOOD - allows patch updates

terraform { required_providers { aws = { source = "hashicorp/aws" version = "~> 5.0" } } }

BAD - exact version (breaks updates)

version = "5.31.0"

BAD - no constraint (unpredictable)

version = ">= 5.0"

Report Format

MAINTAINABILITY SCORE: X/10

Formatting: PASS/FAIL Variable Descriptions: X/Y documented Locals Usage: GOOD/UNDERUSED Naming Consistency: CONSISTENT/INCONSISTENT Version Constraints: PROPER/NEEDS FIX

Issues Found:

• Run tofu fmt -recursive
• Add descriptions to variables: X, Y, Z
• Extract repeated value "us-east-1" to local
• Change exact version to ~> constraint