com.comcast.ip4s.DnsPlatform.scala Maven / Gradle / Ivy
/*
* Copyright 2018 Comcast Cable Communications Management, LLC
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.comcast.ip4s
import cats.effect.kernel.Sync
import cats.syntax.all._
import java.net.InetAddress
private[ip4s] trait DnsCompanionPlatform {
implicit def forSync[F[_]](implicit F: Sync[F]): Dns[F] = new UnsealedDns[F] {
def resolve(hostname: Hostname): F[IpAddress] =
F.blocking {
val addr = InetAddress.getByName(hostname.toString)
IpAddress.fromBytes(addr.getAddress).get
}
def resolveOption(hostname: Hostname): F[Option[IpAddress]] =
resolve(hostname).map(_.some).recover { case _: UnknownHostException => None }
def resolveAll(hostname: Hostname): F[List[IpAddress]] =
F.blocking {
try {
val addrs = InetAddress.getAllByName(hostname.toString)
addrs.toList.flatMap(addr => IpAddress.fromBytes(addr.getAddress))
} catch {
case _: UnknownHostException => Nil
}
}
def reverse(address: IpAddress): F[Hostname] =
F.blocking {
address.toInetAddress.getCanonicalHostName
} flatMap { hn =>
// getCanonicalHostName returns the IP address as a string on failure
Hostname.fromString(hn).liftTo[F](new UnknownHostException(address.toString))
}
def reverseOption(address: IpAddress): F[Option[Hostname]] =
reverse(address).map(_.some).recover { case _: UnknownHostException => None }
def reverseAll(address: IpAddress): F[List[Hostname]] =
reverseOption(address).map(_.toList)
def loopback: F[IpAddress] =
F.blocking(IpAddress.fromInetAddress(InetAddress.getByName(null)))
}
}