Project Chariott

• CI Status
• What is Chariott?
• How to develop with Chariott
  • Terminology
  • Concept of Intents
• Requirements
• Getting started
  • Dev Container
  • Build all binaries and run tests
  • Using Podman instead of Docker
• How to run the examples and interact with Chariott
• How to run the dog mode demo
• Trademarks

CI Status

• Rust CI
• E2E CI
• Security Audit

What is Chariott?

Chariott is a gRPC service that provides a common interface for interacting with applications. Applications communicate between each other through Chariott. Chariott provides the necessary services to enable application lifecycle management and communication between applications. This is done by having applications register an intent which Chariott will then fulfil by brokering the communication with the appropriate application to fulfil that intent. Applications which fulfil these intents are known as providers.

How to develop with Chariott

Chariott provides gRPC interfaces to interact from a client application. The client application can be written in any language that supports gRPC. The examples in this repository are written in Rust, but the same concepts apply to any language.

Terminology

Term	Description
Application	As application we describe a client that is interacting with Chariott to lookup providers and interact with them through Chariott using intents
Provider	A provider is also an application and in addition registers namespaces with intents that it supports to the Chariott endpoints that other applications can use through Chariott

Concept of Intents

Intents are the main way to interact with Chariott. Once a provider registers an intent with Chariott, other applications can use that intent to interact with the provider. The intent is a gRPC method that is defined in the provider's protobuf definition. That definition is only used by Chariott itself.

Chariott also provides a gRPC interface for applications to interact with providers and delegates the calls based on the intent to the provider transparently. Therefore, clients don't need to know the location and details of the provider as long as their intent is fulfilled.

Here is a list of the current supported intents:

Intent	Description
Discover	Retrieve native interfaces of providers. This comes in handy if you need specific interaction with a provider that you know is available in the system and you don't want to use Chariott to interact with it. This is also used for retrieving the streaming endpoints of a provider.
Inspect	Support inspection of functionality, properties and events using a simple query syntax.
Invoke	Invoke a method on a provider.
Subscribe	Subscribe to events of a provider. Note that this does not open the streaming channel, this is done through the native streaming endpoint of the provider.
Read	Read a property of a provider.
Write	Write a property to a provider.

More information can be found in the protobuf definitions in ./proto.

There is a separate document that describes the example applications and scenarios that are supported by Chariott. It can be found here.

Requirements

The current source is developed and tested under WSL2/Linux running Ubuntu 20.04 on AMD64 architecture. It is not tested against any other configurations. You might experience missing support for other platforms, but please feel free to contribute to close the gaps.

Getting started

Dev Container

For development and running the examples, we recommend using the Devcontainer template provided at .devcontainer/devcontainer.json. If you decide not to use the Devcontainer, refer to the devcontainer.json for a list of the plugins/tools we use.

Note: If you use Devcontainers and you are running on Windows, make sure to check out the repository on the WSL2 file system in the target distribution you're using.

Build all binaries and run tests

cargo build --workspace
cargo test --workspace

Using Podman instead of Docker

If you want to use Podman you have to enable Podman in Visual Studio Code and update the .devcontainer/devcontainer.json file with the following additions:

{
  // ...
  "runArgs": [
    "--cap-add=SYS_PTRACE",
    "--security-opt",
    "seccomp=unconfined",
    "--userns=keep-id"
  ],
  // ...
  "workspaceMount": "source=${localWorkspaceFolder},target=/workspace,type=bind,Z",
  "workspaceFolder": "/workspace",
  "containerUser": "vscode",
  // ...
}

NOTE: Feel free to use another workspace folder name.

How to run the examples and interact with Chariott

As Chariott's out of the box communication protocol is gRPC, the interaction with the examples is done through gRPC. To illustrate how to invoke the gRPC methods we use the grpcurl command line tool with the example application kv-app. The kv-app is a key-value store that can be used to store and read state. The state is stored in memory and is not persisted. It also demonstrates the use of the ess and keyvalue crates.

This walkthrough is described in the examples kv-app README.

How to run the dog mode demo

To run the dog mode demo, please refer to the dog mode demo.

Trademarks

This project may contain trademarks or logos for projects, products, or services. Authorized use of Microsoft trademarks or logos is subject to and must follow Microsoft's Trademark & Brand Guidelines. Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship. Any use of third-party trademarks or logos are subject to those third-party's policies.