moleculer-rs
Inspired and compatible with Moleculer JS
You can currently do all the basics of emit
, broadcast
and call
.
However it only works with the NATS
transporter and JSON
serializer/deserializer.
Getting Started
Available on crates: crates.io/moleculer
Documentation available at: docs.rs/moleculer
moleculer = "0.3.3"
Simple example showing how to receive an event, and responding to a request, for more check the examples folder
use std::error::Error;
use moleculer::{
config::{ConfigBuilder, Transporter},
service::{Context, Event, EventBuilder, Service},
ServiceBroker,
};
use serde::Deserialize;
#[tokio::main]
async fn main() -> eyre::Result<()> {
env_logger::init();
color_eyre::install()?;
let config = ConfigBuilder::default().transporter(Transporter::nats("nats://localhost:4222"))
.build();
let print_hi = EventBuilder::new("printHi").add_callback(print_hi).build();
let print_name = EventBuilder::new("printName")
.add_callback(print_name)
.build();
let math_action = ActionBuilder::new("mathAdd").add_callback(math_add).build();
let greeter_service = Service::new("rustGreeter")
.add_event(print_hi)
.add_event(print_name)
.add_action(math_action);
let service_broker = ServiceBroker::new(config).add_service(greeter_service);
service_broker.start().await;
Ok(())
}
fn print_hi(_ctx: Context<Event>) -> Result<(), Box<dyn Error>> {
println!("Hello from Rust");
Ok(())
}
fn print_name(ctx: Context<Event>) -> Result<(), Box<dyn Error>> {
let msg: PrintNameMessage = serde_json::from_value(ctx.params)?;
println!("Hello to: {} from Rust", msg.name);
Ok(())
}
fn math_add(ctx: Context<Action>) -> Result<(), Box<dyn Error>> {
let msg: ActionMessage = serde_json::from_value(ctx.params.clone())?;
let answer = msg.a + msg.b;
let _ = ctx.reply(answer.into());
Ok(())
}
#[derive(Deserialize)]
struct PrintNameMessage {
name: String,
}
#[derive(Deserialize)]
struct ActionMessage {
a: i32,
b: i32,
}
Current Status
Usable but missing some options
What it does
- Is discoverable by other moleculer clients
- Only NATS transporter
- Only JSON serialization/deserialization
- Can
emit
and broadcast
events
- Can
call
to send request and wait for response (#20)
- Can respond to events from other molecular clients using callbacks (see: simple event example)
- Can create actions, and respond to requests (#19)
What its missing:
- Tests #17
- Better error handling on actions #24
- Support for different serializer/deserializer #23
- Support for
Bulkhead
, CircuitBreaker
and RetryPolicy
- Support for tracing
- Support for different transporters other than NATS
- Support for different loggers