Adds support for OpenBao

[digiserg]

This PR introduces support for OpenBao as a secret provider.

Following the recent licensing changes to HashiCorp Vault (BSL), many users are transitioning to OpenBao, an open-source community fork under the LF Decentralized Trust. Since OpenBao maintains API compatibility with Vault's core functionality, this implementation leverages the existing Vault logic while allowing users to explicitly define bao as a source.

Changes

• Added openbao to the list of supported secret providers.
• Implemented the OpenBao provider (mirroring the Vault provider logic).
• Updated documentation to include connection examples for OpenBao.
• Added unit tests for the bao prefix to ensure URI parsing works correctly.

Why this is needed

As organizations move away from BSL-licensed software, vals needs to remain a neutral and flexible tool for secret injection. Providing first-class support for OpenBao allows users to migrate their infrastructure without losing the ability to manage secrets via Helmfile and other tools that depend on vals.

How to test

You can now use the openbao prefix in your configuration:

# Example usage
key: ref+openbao://secret/db#user

1. Run an OpenBao instance (e.g., via Docker).
2. Set the environment variable BAO_ADDR and BAO_TOKEN.
3. Run vals eval on a file containing a ref+bao:// URI.

[yxxhero]

@digiserg please fix confilcts and DCO.

[Copilot]

Pull request overview

This PR adds OpenBao support as a new secret provider to vals. OpenBao is an open-source, community-driven fork of HashiCorp Vault under the Linux Foundation, maintaining API compatibility with Vault's core functionality. The implementation strategically reuses the Vault provider logic while introducing OpenBao-specific environment variables and configuration options.

Key changes:

• Added OpenBao as a first-class provider with ref+openbao:// URI support
• Implemented authentication methods (token, approle, kubernetes, userpass) mirroring Vault
• Added comprehensive test coverage following existing provider test patterns

Reviewed changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated 15 comments.

Show a summary per file

File	Description
vals.go	Registers OpenBao provider constant and integrates it into the provider factory
pkg/providers/openbao/openbao.go	Main provider implementation with authentication methods and secret retrieval logic
pkg/providers/openbao/kv_helper.go	Helper functions for KV v1/v2 version detection and path handling
vals_openbao_test.go	Comprehensive test suite covering EvalTemplate, String, Map, and Raw formats
go.mod	Adds openbao/openbao/api/v2 v2.5.0 dependency
go.sum	Checksum entries for the new OpenBao dependency
README.md	Documentation with usage examples and authentication method descriptions