vynil-core

A Rust toolbox for bootstrapping projects that combine a Rhai scripting engine and a Handlebars templating engine, with optional Kubernetes / OCI / S3 handlers.

vynil-core is the generic layer extracted from vynil so it can be reused by other projects (kuberest, kydah, …) without pulling in vynil's business abstractions (CRDs, package model, instance controllers).

Status: extracted from the vynil workspace and published independently. The public API is not yet stable — expect breaking changes before 1.0.

What it provides

Rhai engine — Script::new_bare(resolver_paths) with the generic helpers (datetime, hashes, password, ed25519 keys, semver, glob, shell, serde-YAML, base64/json, file I/O).
Handlebars engine — HandleBars::new() with the generic helpers (base64, bcrypt, argon, password, encoding, concat, plus the handlebars_misc_helpers set) and engine_mut() to extend it.
HTTP — RestClient (reqwest) and its mock RestClientMock.

A plain vynil-core = "x" dependency (default features) gets all three, unchanged from previous releases. Each is independently optional for a consumer that only needs one — see below.

Features

Feature	Default	Adds	Pulls in
`rhai`	on	The Rhai scripting engine (`Script`) and every other module's Rhai bindings	`rhai`
`hbs`	on	The Handlebars templating engine (`HandleBars`)	`handlebars`, `handlebars_misc_helpers`, `jmespath`, `toml`
`http`	on	`RestClient` (reqwest) + its mock. Implies `rhai` — `RestClient` stores its headers as a Rhai `Map` internally	`reqwest`, `schemars`, `tokio`, `rhai`
`crypto`	on	`argon_hash`/`bcrypt_hash`/`gen_private_key` (Handlebars "always" helpers) and the matching Rhai bindings	`openssl`, `argon2`, `bcrypt`
`k8s`	off	generic K8s handlers + their mocks. Implies `rhai` — `K8sGeneric` is a Rhai-facing API throughout	`kube`, `k8s-openapi`, `futures`, `tokio`, `rhai`
`oci`	off	`Registry` + OCI mock. Implies `rhai`, same reasoning as `k8s`	`oci-client`, `tokio`, `rhai`
`s3`	off	`S3` client. Implies `rhai`, same reasoning as `k8s`	`object_store`, `futures`, `tokio`, `rhai`
`fs`	off	Filesystem access from Rhai scripts	—
`shell`	off	Shell command execution	—
`password`	off	`gen_password`/`gen_password_alphanum` (off by default to avoid a name collision with a consumer's own password semantics)	`rand`

# default: Rhai + Handlebars + HTTP + crypto helpers, same as previous releases
vynil-core = "0.7"

# Kubernetes project
vynil-core = { version = "0.7", features = ["k8s"] }

# Handlebars only (e.g. rendering MCP tool output), no Rhai engine at all
vynil-core = { version = "0.7", default-features = false, features = ["hbs", "crypto"] }

Client identity

vynil-core performs HTTP calls (and, with the k8s feature, Server-Side-Apply calls) on behalf of the consuming application. It does not assume an identity for you — call vynil_core::set_client_name(...) once at startup, before issuing any request:

vynil_core::set_client_name(|| "my-app.example.com".to_string());

Any RestClient or k8s call made before this is configured will panic with a message explaining what to do.

Minimal example

let mut script = vynil_core::Script::new_bare(vec!["scripts/".into()]);
script.engine.register_fn("my_fn", my_fn);          // register your own helpers
script.run_file(&std::path::PathBuf::from("scripts/run.rhai"))?;

let mut hbs = vynil_core::HandleBars::new();
hbs.engine_mut().register_helper("my_helper", Box::new(my_helper));
let output = hbs.render(template_str, &data)?;

What it does NOT include

The vynil-specific layer stays in vynil: CRDs, VynilContext, VynilPackage, the instance macros, the order-preserving YamlDoc, and the context-aware Handlebars helpers (selector_from_ctx, labels_from_ctx, image_from_ctx, …). Consumers add their own on top of the Script/HandleBars engines.

License

BSD 3-Clause (same as vynil).