Struct DnsDiscovery

pub struct DnsDiscovery { /* private fields */ }

DNS node discovery

When asked to resolve a NodeId, this service performs a lookup in the Domain Name System (DNS).

It uses the Endpoint’s DNS resolver to query for TXT records under the domain _iroh.<z32-node-id>.<origin-domain>:

• _iroh: is the record name
• <z32-node-id> is the NodeId encoded in [z-base-32] format
• <origin-domain> is the node origin domain as set in DnsDiscovery::new.

Each TXT record returned from the query is expected to contain a string in the format <name>=<value>. If a TXT record contains multiple character strings, they are concatenated first. The supported attributes are:

• relay=<url>: The URL of the home relay server of the node

The DNS resolver defaults to using the nameservers configured on the host system, but can be changed with crate::endpoint::Builder::dns_resolver.

Implementations

impl DnsDiscovery

pub fn new(origin_domain: String) -> Self

Creates a new DNS discovery.

pub fn n0_dns() -> Self

Creates a new DNS discovery using the iroh.link domain.

This uses the N0_DNS_NODE_ORIGIN_PROD domain.

Usage during tests

For testing it is possible to use the N0_DNS_NODE_ORIGIN_STAGING domain with DnsDiscovery::new. This would then use a hosted staging discovery service for testing purposes.

Trait Implementations

impl Debug for DnsDiscovery

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Discovery for DnsDiscovery

fn resolve( &self, ep: Endpoint, node_id: NodeId, ) -> Option<BoxStream<Result<DiscoveryItem>>>

Resolves the AddrInfo for the given NodeId.

fn publish(&self, _info: &AddrInfo)

Publishes the given AddrInfo to the discovery mechanism.

fn subscribe(&self) -> Option<BoxStream<DiscoveryItem>>

Subscribe to all addresses that get passively discovered.