ansible-vars 1.0.1

Manage vaults and variable files for Ansible

ansible-vars

Manage vaults and variable files for Ansible.

Introduction

This project was motivated by a need to have Ansible vaults readable to humans and external programs like grep without a manual decryption step, while keeping secret values in these vaults secure from prying eyes. Ansible actually supports keeping vaults plain-text and only encrypting individual string variables, but this feature is not widely known or used and editing such files is not supported by the ansible-vault tool.

ansible-vars allows you to do the same things ansible-vault does (and more!), but not just for fully encrypted vaults, but also plain variable files and vaults with hybrid encryption (encrypted variables and/or full encryption). This is significantly more complex, as ansible-vault can be agnostic to the contents of the file it en-/decrypts, while hybrid encryption requires full round-trip parsing of a vault's Jinja2 YAML code.

The main features are:

• Create and edit vaults and variable files with hybrid encryption support.
• Continuously sync a decrypted copy of your vault file(s) to a specified directory.
• Programatically change a vault's variables from Python or from your shell (experimental).
• Compare different versions of a vault and optionally log changes.

Many convenience features have been implemented, such as:

• Convert any of your old fully encrypted vaults to a hybrid vault with just one command.
• Automatically load vault secrets from the Ansible configuration.
• Smart search paths for vault files and directories.
• Full bash/zsh completion.

The extensive help function (ansible-vars [command] -h) will explain each feature in detail.

Installation

You need to have a current version of Python installed. The CLI and library have been tested in Python 3.12, but will likely work with earlier versions as well.

Using a virtual environment

# Create and activate virtual environment
python -m venv venv
source venv/bin/activate
# Install pip package
pip install ansible-vars

Note that the virtual environment must be active when using the command.

Using pipx

# Install pipx
pip install pipx
# Install pip package globally using pipx
pipx install ansible-vars

Shell completion

For bash and zsh users, shell completion for ansible-vars can be activated by adding this command to your shell RC file:

# Add to .bashrc/.zshrc in your user's home
# If you installed ansible-vars to a venv, the venv must be active when this command runs
eval "$(register-python-argcomplete ansible-vars)"

Alternatively, you can install the argcomplete completion system globally.

Usage

The functions of ansible-vars are accessed by specifying a command as the first argument. You can quickly get relevant information by using the help function (ansible-vars [command] -h), optionally specifying the command you want more details about.

Variable encryption

When editing a vault or variable file using ansible-vars, you can prefix any string value using the !enc tag to have it encrypted automatically:

my_message: !enc this is a super secret message

Encrypted variables will be displayed using this tag when editing, making it easy to view, modify, or decrypt their value.

Vault secrets

TL;DR: Run ansible-vars from your Ansible home to auto-detect configured secrets. Add a custom secret using -k <identifier> <passphrase>.

To use any functions of ansible-vars that require encrypting or decrypting data, you need to provide one or multiple vault secret(s). If you're in an Ansible home directory when running the command, it tries to auto-detect configured vault secrets by calling the Ansible CLI API. You can also specify your own secrets as pairs of identifier and passphrase using --add-key|-k <identifier> <passphrase>. The identifier can be anything you want, although it should ideally be unique. Consider using an environment variable or in-line command to retrieve the passphrase from a secure location.

By default, the first loaded key is used for all encryption tasks. Note that auto-detected keys are inserted into the application's keyring after your explicitly added ones, so the first key you add will usually be the encryption key. If you want to make sure a certain key is used, reference its identifier using --encryption-key|-K <identifier>.

You can disable automatic key detection by flagging --no-encrypt-keys|-D. Use ansible-vars keyring to view all available keys.

Diff logging

TL;DR: You can use -l <log directory> to log changes to edited vaults to a vault-encrypted log file.

You can automatically log any changes performed to a vault by the commands create, edit, convert, set, and del using the --log|-l <log path> or --log-plain|-L <log path> flags. The changes will be saved as a YAML-compatible diff with some additional metadata. When using --log, the entire log file is encrypted as a vault using your encryption key. This is important as the diffs contain the plain values of encrypted variables. When using --log-plain to skip encryption, make sure you're only editing fully plaintext variable files to avoid leaking secrets.

As you cannot mix different encryption keys and/or plain logging in the same log file, consider either using a dedicated logging key (--logging-key <identifier>) or specifying a directory as the log path (in which case ansible-vars automatically chooses a filename based on the used encryption key's identifier) if you frequently switch between keys.

Examples

# Create the variable file `./host_vars/my_host/main.yml` without full encryption and open it for editing
ansible-vars create --make-parents --plain host_vars/my_host/main.yml
# Short version (see `Tips` section to learn about vault search paths)
ansible-vars create -mp h:my_host

# Decrypt the vault file `./config/logging.yml` in-place
ansible-vars decrypt file config/logging.yml

# Recursively search vaults and variable files in `./host_vars` for left-over TODOs
ansible-vars grep '# TODO' h:

# Print a tree structure showing the differences between two versions of the vault `./vars/passwords.yml`
ansible-vars changes v:passwords.yml.old v:passwords.yml

# Create decrypted mirrors of the directories `./host_vars`, `./group_vars`, and `./vars` in `/tmp/decrypted`
ansible-vars file-daemon /tmp/decrypted

# Get the decrypted value of `<vault root>['my_key'][4]['133']` in `./group_vars/database_hosts/main.yml` as JSON
ansible-vars get --json g:database_hosts 'my_key' '[4]' '133'

Tips

• When a command supports a --json flag, the command's help (ansible-vars <command> -h) will define the returned structure.
• The directories host_vars, group_vars, and vars are common vault locations. When in their parent directory, you can use the prefixes h:, g:, and v: in any vault path you specify, followed by a path relative to them. Wherever a directory is not expected as a path, supplying a directory path will also append a main.yml to the path automatically. In summary, this lets you type h:my_host when you actually mean ./host_vars/my_host/main.yml. Shell completion for these prefixed paths is provided.
  • These three directories are also default sources for the file-daemon command.
• When referencing vault traversal keys, you can specify numbers to access lists and number-indexed dictionaries. However, just specifying 2 as a key segment will resolve into the string '2'. Instead, you should write [2] to mark it as a number index. If you need to specify the string '[2]' for some reason, you can escape it by adding another set of brackets (and so on).

Commands

A brief overview of the available commands. You can change a lot of the default behavior described here using command flags. Use the command help to get additional information and available flags (ansible-vars <command> -h).

keyring

Displays the loaded vault secrets, including any auto-detected ones, along with their passphrase. Supports JSON output.

create

Creates a new vault or variable file. By default, full encryption is enabled to avoid accidentally leaking secrets. Use the --plain|-p flag to create a file with hybrid encryption, i.e. completely plain or with individually encrypted variables. After creating the file, it will open in edit mode (see edit command below).

edit

Opens a vault or variable file in the configured editor (EDITOR environment variable or passed using the --edit-command|-e flag) in decrypted form. Here, you can en-/decrypt, add, remove, and change variables. After saving the file and closing the editor, the file will be re-parsed and re-encrypted.

Note: When choosing a custom edit command, make sure the command exits after the file is saved, as ansible-vars will read a finished command as the cue to start re-parsing the file contents.

view

Prints the contents of a vault or variable file to the terminal, fully decrypted without any encryption markers. Supports JSON output.

info

Shows the amounts of encrypted and decrypted variables in a vault file. Supports JSON output.

encrypt, decrypt, is-encrypted

En-/Decrypts or checks the encryption status of a file or string value. No loaded secrets are required for is-encrypted.

convert

Convenience function to convert between fully encrypted vaults and hybrid vaults. Useful if you wish to convert your "legacy" fully encrypted vaults to plain files with all string values individually encrypted. Works both ways.

grep

Searches one or multiple vault(s) for matches on a pattern, either in their full text or limited to keys/values. Supports recursively searching directories and JSON output. Note that non-variable/-vault files are not included in the search.

diff

Compares two vaults or variable files and prints the line diff.

changes

Compares two vaults or variable files and prints a tree structure showing differences between their variables. Supports JSON output.

file-daemon

Starts a daemon which mirrors the decrypted contents of one or multiple vault or variable file(s)/directories to a target directory. By default, this includes the directories ./host_vars, ./group_vars, and ./vars. Changes to the source files are reflected in the decrypted targets. Changes to the target files are ignored.

get

Displays the (decrypted) value of a specified key in a vault or variable file. Supports dictionary and list traversal, and JSON output.

set, del (experimental)

Creates, updates, or deletes a key-value pair from a vault or variable file. When setting a value, you may provide a YAML string which will be parsed into the corresponding objects. Note that these are experimental features, as the current parser has difficulty preserving the metadata for programmatic variable changes. Comments and Jinja2 blocks between the affected key and the next key in the file may be lost.

Python library

When using ansible-vars as a library, import any of these modules from the ansible_vars module.

vault module

Contains the classes Vault and VaultFile. A Vault is initialized using the contents of a vault or variable file, while VaultFile wraps around a Vault instance and manages reading from and writing to a file directly. These are the main classes you'll likely use, as they contain the means of loading, manipulating and exporting vault and variable data. Both can also be initialized using an 'editable' (the output of <vault>.as_editable(), contains encryption markers and an optional explanatory comment header). A vault_crypt.VaultKeyring is required for en-/decryption operations.

EncryptedVar represents an encrypted value. The stored cipher can be decrypted using a vault_crypt.VaultKey(ring). Will be dumped as !vault-tagged values on exporting.

ProtoEncryptedVar is used for parsing, as the !enc tag parses into such a proto-var and is then converted to an EncryptedVar, and vice-versa for exporting.

vault_crypt module

The VaultKey class represents a single vault secret, comprised of an identifier and an ansible.parsing.vault.VaultSecret. Can be initialized using a plain passphrase instead of a VaultSecret as well.

The VaultKeyring combines a collection of VaultKeys. It supports auto-detection of any secrets available in the present working directory using the ansible.cli module, appending them to the <keyring>.keys collection. While all keys are tried in order for decryption operations, only one key can be used for encrypting data. This key is usually the first key in the <keyring>.keys collection, unless explicitly specified otherwise using <keyring>.default_encryption_key or passing a key to the <keyring>.encrypt() method.

util module

The DiffLogger with its wrapper DiffFileLogger generate log entries for changes to a vault and can save them to an encrypted or plain log file. A method decorator (@<file logger>.log_changes(<vault used in wrapped method>)) is available for your convenience.

The VaultDaemon syncs changes from a source file or directory to a target using the watchdog library, decrypting any vaults encountered on the way.

constants & errors modules

Custom types and exceptions, and static values. Mostly useful for type hints.

Known issues and limitations

• YAML round-trip parser
  • Trailing comments and Jinja2 blocks may be misaligned and a trailing newline may be inserted/removed when switching between folded (|, >) and non-foldes values.
  • The set and del commands may remove trailing comments and Jinja2 blocks.
  • Explicit start/end markers (---, ...) are not preserved.
  • Supports lists, dictionaries, and scalar values.
  • Does not support custom YAML tags (!tag).
• Ansible
  • Ansible only directly supports encrypted string values (although you can work around this with the from_yaml filter).
  • Ansible-encrypted strings must include a newline between the envelope and the cipher.
  • Ansible vault and variable file roots must be a dictionary.
• grep command
  • Will ignore files which cannot be parsed as an Ansible YAML file.
• file-daemon command
  • Changes to file metadata (permissions, ...) are not mirrored.

Extension plans

• I'm debating creating my own Jinja2 YAML round-trip parser to alleviate the metadata preservation issues of the current parser.
• I may add an Ansible action plugin for updating vault variables directly from an Ansible task (useful e.g. for automatically storing passwords that are set to a random value by Ansible). I am currently using a small script for this task.
• I want to create ansible-vars system packages for common repositories.