The StaticPeerProvider

A peer provider is responsible for returning a list of available peers for the connection layer to choose from.

The static peer provider allows configuring a predefined, static list of peer endpoints.

The Peer Provider Trait

#![allow(unused)]
fn main() {
pub trait PeerProvider: std::fmt::Debug + Send + Sync {
    /// Initializes the peer provider.
    fn init(&self) -> Result<(), Box<dyn StdError + Send + Sync>>;

    /// Returns a vector of available peers.
    fn get(&self) -> Vec<Peer>;
}
}

As seen in the architecture chapter, the PeerProvider trait requires a peer provider to implement a get function that returns a vector of peers.

A peer is defined as follows:

#![allow(unused)]
fn main() {
pub enum Peer {
    Ipv4Addr(Ipv4Addr),
    SocketAddrV4(SocketAddrV4),
}
}

A peer is an enum with either an Ipv4 or a full socket address. The reason behind this is to allow a peer provider to return a vector of ip address or ip:port.

The Static Peer Provider

#![allow(unused)]
fn main() {
#[derive(Serialize, Deserialize, Debug)]
pub struct Static {
    peers: Vec<Peer>,
}

#[typetag::serde]
impl PeerProvider for Static {
    fn init(&self) -> Result<()> {
        Ok(())
    }

    fn get(&self) -> Vec<Peer> {
        self.peers.clone()
    }
}
}

The Static struct is loaded by the configuration module and is expecting a vector of ip or ip:port values.

peer_provider:
  kind: Static
  peers:
    - 192.168.1.2
    - 192.168.1.3:3000

The get function implementation just returns that list.

Feel free to browse the K8s peer provider code to see a more complex implementation for a peer provider.