Crate wasmcloud_host 

wasmCloud Host

wasmCloud is an open source Cloud Native Computing Foundation (CNCF) project that enables teams to build, manage, and scale polyglot Wasm apps across any cloud, K8s, or edge.

⚠️ This crate is highly experimental and likely to experience breaking changes frequently. The host itself is relatively stable, but the APIs and public members of this crate are not guaranteed to be stable.

Usage

This crate can be used to embed a wasmCloud host in a Rust application. You can refer to the wasmcloud-main-rs file of the wasmCloud runtime for an example of this.

This library provides the host runtime for wasmCloud, which is a platform for running WebAssembly (Wasm) components and plugins. It includes pluggable support for various extensions and integrations, allowing developers to customize and extend the host’s functionality.

Key Modules

• config: Implements the crate::config::ConfigManager trait for managing a configuration store that can be watched for updates. This is a supertrait of crate::store::StoreManager and is implemented by crate::store::DefaultStore.
• event: Provides the crate::event::EventManager trait for handling and dispatching events from the wasmCloud host
• metrics: Implements OpenTelemetry metrics for wasmCloud, primarily using the crate::metrics module for tracing and monitoring.
• nats: Contains the NATS-based implementations for the wasmCloud host extension traits
• oci: Offers configuration and utilities for fetching OCI (Open Container Initiative) artifacts
• policy: Defines the crate::policy::PolicyManager trait for applying additional security policies on top of the wasmCloud host.
• registry: Provides the crate::registry::RegistryCredentialExt extension trait for working with registry credentials and configurations.
• secrets: Contains the crate::secrets::SecretsManager trait for securely fetching secrets from a secret store.
• store: Defines the crate::store::StoreManager trait for managing configuration and data from a backing store.
• wasmbus: Contains the core implementation of the wasmCloud host functionality, including the crate::wasmbus::Host struct and related configurations.
• workload_identity: Experimental module for workload identity implementations, providing tools for identity management.

Extending the Host

The top-level modules in this crate expose implementable extension traits that allow developers to extend the host’s functionality. These traits can be supplied to an embedded host using the crate::wasmbus::HostBuilder.

For example, you can implement custom policies, secrets management, or registry configurations to tailor the host to your specific needs.

The wasmCloud wasmcloud-main-rs binary uses the implementations in nats to provide a NATS-based host runtime. This allows you to run wasmCloud components and plugins in a distributed environment, leveraging NATS for messaging and communication.

Getting Started

To get started with wasmCloud, refer to wasmbus for the core host functionality. From there, you can explore the other modules to add extensions and integrations as needed.

For more information, visit the wasmcloud-homepage.

Re-exports

pub use oci::Config as OciConfig;

pub use policy::HostInfo as PolicyHostInfo;

pub use policy::PolicyManager;

pub use policy::Response as PolicyResponse;

pub use wasmbus::Host as WasmbusHost;

pub use wasmbus::HostConfig as WasmbusHostConfig;

Modules

config

crate::config::ConfigManager trait for managing a config store which can be watched to receive updates to the config. This is a supertrait of crate::store::StoreManager and is implemented by crate::store::DefaultStore.

event

crate::event::EventPublisher trait for receiving and publishing events from the host

metrics

Implementation of OpenTelemetry metrics for wasmCloud, primarily using wasmcloud_tracing

nats

NATS implementations of crate::policy::PolicyManager, crate::secrets::SecretsManager, and crate::store::StoreManager traits for the wasmCloud host. NATS implementations of wasmCloud crate::wasmbus::Host extension traits

oci

Configuration for OCI artifact fetching crate::oci::Config

policy

crate::policy::PolicyManager trait for layering additional security policies on top of the wasmCloud host

registry

crate::registry::RegistryCredentialExt extension trait for converting registry credentials into wasmcloud_core::RegistryConfig

secrets

crate::secrets::SecretsManager trait for fetching secrets from a secret store Module with structs for use in managing and accessing secrets in a wasmCloud lattice

store

crate::store::StoreManager trait for fetching configuration and data from a backing store Module with structs for use in managing and accessing data used by various wasmCloud entities

wasmbus

crate::wasmbus::Host implementation

workload_identity

experimental workload identity implementation

Enums

ResourceRef

A reference to a resource, either a file, an OCI image, or a builtin provider

Functions

fetch_component

Fetch an component from a reference.