pyenvgen

Warning: This project was vibe coded and is in early development. Expect breaking changes and incomplete features. Contributions are welcome!

Python tool to generate environment variables from YAML schemas.

1. Define variables in a YAML schema, including types, generation rules, and validation constraints.
2. Existing values are loaded from the chosen storage backend.
3. Values are generated (with existing/overridden values taking precedence), then validated.
4. The final environment is written back to the storage backend.

Installation

pip install pyenvgen

Usage

pyenvgen <schema.yaml> [-s STORAGE] [-b BACKEND] [-o KEY=VALUE ...] [--force]

# Print to stdout
pyenvgen examples/basic.yaml

# Write to a .env file
pyenvgen examples/basic.yaml -s .env

# Override a value
pyenvgen examples/basic.yaml -o APP_PORT=9000

Schema format

variables:
  MY_VAR:
    type: str          # str | int | float | bool (default: str)
    description: "..."
    internal: false    # default: false
    generation:
      rule: default
      value: "hello"
    validation:
      length:
        min: 1
        max: 128

Variable types

str, int, float, bool

Generation rules

All string fields in generation rules are rendered as Jinja2 templates against already-generated values before execution.

• default – use a static value (supports Jinja2, e.g. "postgres://{{ HOST }}:{{ PORT }}/app")
• command – run a shell command and capture its stdout
• openssl – generate cryptographic material via the cryptography package

openssl commands

Validation rules

Backed by marshmallow.

Storage backends

Special properties

• internal: true – the variable is generated and available to Jinja2 templates but excluded from the output.