/DNSClient

A DNS Resolver in Swift

Primary LanguageSwiftMIT LicenseMIT

NioDNS

Async DNS resolution, with all the DNS features you need!

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Installation 💥

Add the package:

.package(url: "https://github.com/orlandos-nl/DNSClient.git", from: "2.0.0"),

And to your target:

.product(name: "DNSClient", package: "DNSClient"),

Usage 🤯

Connect to your default DNS Server using UDP:

let client = try DNSClient.connect(on: loop).wait()

Connect to a specific DNS Server:

let googleDNS = SocketAddress(ipAddress: "8.8.8.8", port: 53)
let client = try DNSClient.connect(on: loop, config: [googleDNS]).wait()

Resolve SRV Records:

let records = try client.sendQuery(forHost: "example.com", type: .srv).wait()

Resolve TXT Records:

let records = try client.sendQuery(forHost: "example.com", type: .txt).wait()

Resolve PTR Records:

let records = try client.ipv4InverseAddress("198.51.100.1").wait()

let records = try client.ipv6InverseAddress("2001:DB8::").wait()

Need I say more?

Note: You can replace .wait() function calls with .get() to get the result using async/await.

iOS and TCP Support

On iOS 12+, you can connect using Network.Framework:

import NIOTransportServices
import DNSClient

let client = try DNSClient.connect(on: loop, host: "1.1.1.1").wait()

There is also another overload that implements TCP support:

let client = try DNSClient.connectTSTCP(on: loop, host: "1.1.1.1").wait()

TCP support is also available on Linux as DNSClient.connectTCP(on: loop, host: ...)

Note that NIOTS (TransportServices) needs their own EventLoop type, whereas NIO's MultiThreadedEventLoopGroup is used for the POSIX/Linux implementation.

Notes

The DNS Client doesn't retain itself during requests. This means that you cannot do the following:

DNSClient.connect(on: request.eventLoop).flatMap { client in
    // client.doQueryStuff()
}

The client will deallocate itself, resulting in a timeout. Make sure that the client is strongly referenced, either until all results are in or by setting it on a shared context. In Vapor, that can be the request's storage container. On other services, you could consider a global, ThreadSpecificVariable or a property on your class.

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