http-server

HTTP Server Example

This example demonstrates a composable HTTP server with two types of routes:

1. a component route that invokes a function directly
2. a channel route that publishes a message for a subscribed component

Because the HTTP Server applies inversion of control, neither component has any built-in HTTP request handling. In fact, both routes target the simple hello-world greeter component.

Structure

• config.toml: server, component, and route configuration
• run-server.sh: starts the Composable Runtime with an HTTP Server
• greet.sh: sends requests to both routes via curl

Building and Running

Change into the examples/http-server directory.

1. Start the server:

./run-server.sh

That will build the hello-world example's greeter component if not already built.

Then it starts a long-running Composable Runtime instance with the HTTP Server support enabled, and configures info-level logging.

3. In another terminal, send requests:

./greet.sh

Output:

--- GET /hello/world (component route) ---
"Hello, World!"
--- POST /bonjour (channel route -> subscription -> bonjour component) ---

In the server log, you will see the channel route result logged asynchronously:

... invocation complete component=bonjour function=greet result="Bonjour, le Monde!"

How It Works

1. Component route: GET /hello/{name} maps the {name} path segment to the name argument of hello.greet(name) and returns the result directly.
2. Channel route: POST /bonjour publishes the request body to the "names" channel. The bonjour component subscribes to that channel and is invoked asynchronously.
3. Configuration: The bonjour component definition includes config.greeting = "Bonjour" to differentiate its greeting in the log output.

Configuration

[server.api]
type = "http"
port = 8888

[server.api.route.hello]
path = "/hello/{name}"
component = "hello"
function = "greet"

[server.api.route.bonjour]
path = "/bonjour"
channel = "names"

[component.hello]
uri = "../hello-world/greeter/target/wasm32-unknown-unknown/release/greeter.wasm"

[component.bonjour]
uri = "../hello-world/greeter/target/wasm32-unknown-unknown/release/greeter.wasm"
config.greeting = "Bonjour"
subscription = "names"