Crate netidx[−][src]

Netidx is like DNS for values. With netidx you can name individual values in your program, and other programs can find and subscribe to those values securely over the network.

Like DNS netidx maintains a hierarchical namespace in a resolver server. Publishers tell the resolver about values they have. Subscribers ask the resolver for values they want. Once a subscriber knows where to find a value it is looking for, it connects directly to the publisher, and the resolver is no longer involved.

Publisher

use netidx::{
    publisher::{Publisher, Value, BindCfg},
    config::Config,
    resolver::Auth,
    path::Path,
};
use tokio::time;
use std::time::Duration;

// load the site cluster config. You can also just use a file.
let cfg = Config::load_default()?;

// no authentication (kerberos v5 is the other option)
// listen on any unique address matching 192.168.0.0/16
let publisher = Publisher::new(cfg, Auth::Anonymous, "192.168.0.0/16".parse()?).await?;

let temp = publisher.publish(
    Path::from("/hw/washu-chan/cpu-temp"),
    Value::F32(get_cpu_temp())
)?;
publisher.flush(None).await;

loop {
    time::sleep(Duration::from_millis(500)).await;
    temp.update(Value::F32(get_cpu_temp()));
    publisher.flush(None).await;
}

Subscriber

use netidx::{
    subscriber::{Subscriber, UpdatesFlags},
    config::Config,
    resolver::Auth,
    path::Path,
};
use futures::{prelude::*, channel::mpsc};

let cfg = Config::load_default()?;
let subscriber = Subscriber::new(cfg, Auth::Anonymous)?;
let path = Path::from("/hw/washu-chan/cpu-temp");
let temp = subscriber.subscribe_one(path, None).await?;
println!("washu-chan cpu temp is: {:?}", temp.last());

let (tx, mut rx) = mpsc::channel(10);
temp.updates(UpdatesFlags::empty(), tx);
while let Some(mut batch) = rx.next().await {
    for (_, v) in batch.drain(..) {
        println!("washu-chan cpu temp is: {:?}", v);
    }
}

Published values always have a value, and new subscribers receive the most recent published value initially. Thereafter a subscription is a lossless ordered stream, just like a tcp connection, except that instead of bytes publisher::Value is the unit of transmission. Since the subscriber can write values back to the publisher, the connection is bidirectional, also like a Tcp stream.

Values include many useful primitives, including zero copy bytes buffers (using the awesome bytes crate), so you can easily use netidx to efficiently send any kind of message you like. However it’s advised to stick to primitives and express structure with muliple published values in a hierarchy, since this makes your system more discoverable, and is also quite efficient.

In many environments security is a requirement, whereas in others it’s not necessary. To handle both of these cases netidx includes optional support for kerberos v5 (including Active Directory). If enabled, all components will do mutual authentication between the resolver, subscriber, and publisher as well as encryption of all data on the wire. In addition to authentication, the resolver server in krb5 mode maintains and enforces authorization permissions for the entire namespace, so the resolvers can centrally enforce who can publish where, and who can subscribe to what.

Re-exports

pub use netidx_netproto as protocol;

Modules

chars
config
pack
path
pool
publisher
resolver
resolver_server
subscriber
utils