Env Alias

Env Alias is an environment variable swiss-army-knife that enables loading complex collections of environment variables from a variety of sources only when you require them, thus reducing risks in working with sensitive environment values.

A variety of data-formats are supported including JSON, YAML, Keepass, Ansible Vault, Plaintext and Ini-config where these formats can be sourced from the local-filesystem, http-remote or generated through shell-command exec output.

For example setting an Ansible-vault password file and loading AWS access credentials from values stored in a git project based Keepass file:

env-alias:

  MYPROJECT_KEEPASS_FILE:
    name: null  # prevents this value being assigned into env
    exec: 'echo "$(git rev-parse --show-toplevel)/secrets/myproject-keepass.kdbx"'
  
  MYPROJECT_KEEPASS_PASSPHRASE:
    source: "<getpass>"  # obtain value from user-input using getpass method
    override: false  # if this env-value exists then skip setting again
    
  MYPROJECT_ANSIBLE_VAULT_PASSWORD:
    name: null  # prevents this value being assigned into env
    source: "env:MYPROJECT_KEEPASS_FILE"
    selector: "myproject-name/ansible-vault-entry-name:Password"  # select an item from Keepass file
    keepass_password: "env:MYPROJECT_KEEPASS_PASSPHRASE"

  ANSIBLE_VAULT_PASSWORD_FILE:
    ansible_vault_password: "env:MYPROJECT_ANSIBLE_VAULT_PASSWORD"  # NB: see docs how this gets managed
    ansible_vault_password_file: true  # invoke special helper that renders an Ansible Vault password file

  AWS_SECRET_ACCESS_KEY:
    source: "env:MYPROJECT_KEEPASS_FILE"
    selector: "myproject-name/aws-entry-name:Password"
    keepass_password: "env:MYPROJECT_KEEPASS_PASSPHRASE"
    
  AWS_ACCESS_KEY_ID:
    source: "env:MYPROJECT_KEEPASS_FILE"
    selector: "myproject-name/aws-entry-name:Username"
    keepass_password: "env:MYPROJECT_KEEPASS_PASSPHRASE"

The above example sets the environment variable MYPROJECT_KEEPASS_PASSPHRASE with user input using the getpass Python module only if not already set (override=false). This environment value is then used as the keepass passphrase to open a Keepass file where values are then selected and exported into the shell environment.

Substantially more complex env-alias definitions can be created.

By naming your env-aliases with an easy to remember prefix such as env- it is also possible to leverage shell tab-completion thus making it easier to find the env-alias definitions created for your project or other use-case situation.

Features

Env Alias is enormously useful in working with large sets of environment variables from remote, encrypted or otherwise secured data-sources.

• Data sources: local-files, http-remote and stdout from an exec command-line.
• Source formats supported: JSON, YAML, Keepass, Ansible Vault, Plaintext and Ini-config.
• Select values using jq style selectors, xpath style selectors or line-numbers.
• 💥 Additional special handling for Ansible Vault Password Files that makes credential handling for Ansible Vault files substantially easier with reduced exposure risks. 💥
• Self reference environment values in the definition file or from the existing system environment.
• Define variables with a null name to prevent them being exported into the system environment while still being available for self-reference within the env-alias definition; this is helpful when working with sensitive values that should not be available through the system environment.
• Ability to use exec commands to setup other project prerequisites or other project start conditions.
• Debug mode output to STDERR.
• Easy installation from PyPI.
• Plenty of documentation and examples - https://env-alias.readthedocs.io

Installation

Pip or pipx should be fine, we prefer pipx these days.

pipx install env-alias

Usage

This tool is typically invoked using an entry in .bash_aliases with an entry of the form:-

source <(env-alias ~/projects/awesome/env-awesome-vars.yml)

This simple .bash_aliases one-line entry creates the alias env-awesome-project by inferring the alias-name from the filename, where this alias then invokes env-alias to set environment values defined in env-awesome-project.yml

Alternatively, you might want to create the alias awesome-envvars which you could do as per -

source <(env-alias awesome-envvars ~/projects/awesome/env-awesome-vars.yml)

Project

• Github - github.com/ndejong/env-alias
• PyPI - pypi.python.org/pypi/env-alias
• ReadTheDocs - env-alias.readthedocs.io

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Copyright © (2020-2024) Nicholas de Jong