mpe lint

Validate PolicyDomain YAML files for syntax errors and lint embedded Rego code.

Synopsis

mpe lint --file <file> [--opa-flags <flags>] [--no-opa-flags]

Description

The lint command performs comprehensive validation:

1. YAML validation: Checks for valid YAML syntax
2. Rego compilation: Compiles all embedded Rego code
3. Dependency resolution: Validates cross-references between policies and libraries
4. OPA check: Runs opa check for additional linting

Options

Option	Alias	Description	Required
--file	-f	PolicyDomain YAML file(s) to lint	Yes
--opa-flags		Additional flags for opa check	No
--no-opa-flags		Disable all OPA flags	No

Examples

Lint a Single File

mpe lint -f my-domain.yml

Lint Multiple Files

mpe lint -f domain1.yml -f domain2.yml

With Custom OPA Flags

mpe lint -f my-domain.yml --opa-flags "--strict"

Without OPA Flags

mpe lint -f my-domain.yml --no-opa-flags

Output

Success

Linting YAML files...

✓ my-domain.yml: Valid YAML
✓ my-domain.yml: Valid Rego in library 'utils'
✓ my-domain.yml: Valid Rego in policy 'main'
✓ my-domain.yml: Valid Rego in policy 'admin'
✓ my-domain.yml: Valid Rego in mapper 'http-mapper'
---
All checks passed: 1 file(s) validated successfully

YAML Error

Linting YAML files...

✗ my-domain.yml (YAML)
  Error: yaml: line 15: found character that cannot start any token

Rego Error

Linting YAML files...

✓ my-domain.yml: Valid YAML
✗ my-domain.yml (Rego in policy 'main')
  Error: 1 error occurred: policy.rego:5: rego_parse_error: unexpected token

Dependency Error

Linting YAML files...

✓ my-domain.yml: Valid YAML
✗ my-domain.yml (Reference error: library 'unknown-lib' not found)

Auto-Build

The lint command automatically builds PolicyDomainReference files before linting:

# If my-domain.yml is a PolicyDomainReference, it will be built first
mpe lint -f my-domain-ref.yml

OPA Flags

Default OPA flags: --v0-compatible

Override via:

• Command line: --opa-flags "--strict --v1-compatible"
• Environment variable: MPE_CLI_OPA_FLAGS="--strict"
• Disable: --no-opa-flags

Validation Checks

Check	Description
YAML syntax	Valid YAML format
Rego syntax	Parseable Rego code
Rego compilation	Code compiles without errors
Package declaration	Each policy has package authz
Dependency resolution	All dependencies exist
Cross-domain references	External references are valid
OPA check	Additional OPA linting rules

Exit Codes

Code	Description
0	All files valid
1	One or more files have errors

Best Practices

1. Run early and often: Lint during development
2. CI integration: Add to your CI pipeline
3. Pre-commit hook: Lint before commits
4. Fix all warnings: Keep code clean