envcheck

Check your .env file before it blows up in production.

$ python envcheck.py check

  envcheck  .env  ←→  .env.example

  ✓ 14 key(s) present and set
  ! 1 key(s) set to empty:
      REDIS_URL
  ✗ 2 key(s) missing from .env:
      STRIPE_SECRET_KEY  # e.g. sk_live_...
      SENTRY_DSN

Exit code is 0 when everything's set, 1 if anything is missing or empty — so it works as a pre-deploy gate.

Setup

curl -O https://raw.githubusercontent.com/yangming-zhang/envcheck/main/envcheck.py
python envcheck.py --help

Python 3.9+, zero dependencies.

Commands

check   validate .env against a template
diff    compare two .env files
list    show all keys (and whether they're set)
lint    catch formatting problems

Usage

# Check .env against .env.example (default)
python envcheck.py check

# Custom paths
python envcheck.py check .env.production .env.example

# Also show keys that are in .env but not in the template
python envcheck.py check --show-extra

# What changed between two environments?
python envcheck.py diff .env.staging .env.production

# Careful: this prints the actual values
python envcheck.py diff .env .env.backup --show-values

# What keys are set? (values hidden)
python envcheck.py list .env

# Find formatting issues
python envcheck.py lint .env

CI/CD

# GitHub Actions
- name: Validate env
  run: python envcheck.py check .env.ci .env.example

# Pre-deploy check
python envcheck.py check || { echo "fix your .env first"; exit 1; }

What lint catches

• Keys that don't match [A-Za-z_][A-Za-z0-9_]*
• Lines with no = sign
• Spaces inside key names
• Unmatched quotes in values

Notes

• Handles export FOO=bar syntax (common in sourced shell files)
• Strips inline comments: FOO=bar # this part is ignored
• Values don't need to be quoted, but single and double quotes are both supported
• A key with no value at all (just KEY with no =) is treated as None, not empty string

License

MIT