Edgeware Confd Client for Rust

This is a client library for subscribing to configuration changes using Confd for Rust.

Installation

Add the following to your cargo.toml file

[dependencies]
confd-client = { git = "https://github.com/edgeware/confd-client-rs.git", branch="master" }

From the rust-lang book in the chapter on specifying dependencies

Anything that is not a branch or tag falls under rev. This can be a commit hash like rev = "4c59b707", or a named reference exposed by the remote repository such as rev = "refs/pull/493/head". What references are available varies by where the repo is hosted; GitHub in particular exposes a reference to the most recent commit of every pull request as shown, but other git hosts often provide something equivalent, possibly under a different naming scheme.

Once a git dependency has been added, Cargo will lock that dependency to the latest commit at the time. New commits will not be pulled down automatically once the lock is in place. However, they can be pulled down manually with cargo update.

Usage

The following example shows how to subscribe to the integration.convoy.events path and simply print out the configuration on changes. Each time the config is modified in confd the subscribed function will be called.

use confd_client::ClientBuilder;

use serde::Deserialize;

#[derive(Debug, Deserialize)]
pub struct Events {
    pub enable: bool,
    pub servers: Vec<String>,
}

#[tokio::main]
async fn main() -> Result<(), confd_client::Error> {
   let client = ClientBuilder::default()
        .with_subscription(
            "/integration/convoy/events",
            Box::new(|json: serde_json::Value| async move {
                let events: Events =
                    serde_json::from_value(json.get("events").unwrap().clone()).unwrap();
                println!("Got the following: {:?}", events);
            }),
        )
        .build()
        .await?;

    client.listen().await?;
    Ok(())
}

In addition to a closure, an async function can be used as thee subscription. For example:

use confd_client::ClientBuilder;
use serde::Deserialize;

// ...
async fn handle_convoy_events(json: serde_json::Value) {
    let events: Events = serde_json::from_value(json.get("events").unwrap().clone()).unwrap();
    println!("Got the following: {:?}", events);
}

#[tokio::main]
async fn main() -> Result<(), confd_client::Error> {
   let client = ClientBuilder::default()
        .with_subscription(
            "/integration/convoy/events",
            Box::new(handle_convoy_events),
        )
        .build()
        .await?;

    client.listen().await?;
    Ok(())
}

Additional examples are located in the /examples subfolder of this repository.

It is recommended to call listen() from within a spawned task, since that function is designed to run for the lifetime of the program.

E.g.

let listener = tokio::spawn(client.listen());
let _ = tokio::join!(listener);