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Version: 1.x

📡 WADM Status Receiver Example

This folder contains a WebAssembly component that makes use of:

📦 Dependencies​

  • cargo (part of the Rust toolchain) for building this project
  • wash for building and running the components and wasmCloud hosts

👟 Quickstart​

As with all other examples, you can get started quickly by using the Wasmcloud SHell (wash).

Since wash supports declarative deployments (powered by [Wasmcloud Application Deployment Manager (wadm)][wadm]), you can get started quickly using the provided manifests:

Build this component​

console
wash build

This will create a folder called build which contains wadm_status_receiver_s.wasm.

[!NOTE] If you're using a local build of the provider (using file://... in wadm.yaml) this is a good time to ensure you've built the [provider archive par.gz][par] for your provider.

Start a wasmCloud host with WADM​

console
wash up

Deploy the status receiver application​

First, deploy our status receiver component that will listen for updates:

console
wash app deploy local.wadm.yaml

Deploy the example application to monitor​

Now deploy the example application that our receiver will monitor:

console
wash app deploy example.wadm.yaml

You should start seeing status updates in the logs as the example application deploys and its status changes.

To see everything running in the lattice:

console
wash get inventory

To test status changes, you can:

  1. Undeploy the example application:
    console
    wash app undeploy rust-hello-world
  2. Redeploy it:
    console
    wash app deploy rust-hello-world

Each of these actions will generate status updates that our receiver will log.

⌨️ Code guide​

rust
impl Guest for StatusReceiver {
    fn handle_status_update(msg: StatusUpdate) -> Result<(), String> {
        wasi::logging::logging::log(
            wasi::logging::logging::Level::Info,
            "wadm-status",
            &format!(
                "Application '{}' v{} - Status: {:?}",
                msg.app, msg.status.version, msg.status.info.status_type
            ),
        );

        wasi::logging::logging::log(
            wasi::logging::logging::Level::Info,
            "wadm-status",
            &format!("Components found: {}", msg.status.components.len()),
        );

        for component in msg.status.components {
            wasi::logging::logging::log(
                wasi::logging::logging::Level::Info,
                "wadm-status",
                &format!(
                    "Component '{}' - Status: {:?}",
                    component.name, component.info.status_type
                ),
            );
        }
        Ok(())
    }
}