Merge pull request #5 from multiplexd/feature-http-proxy

Add HTTP proxy support for akka-http HTTP requests

example.conf

@@ -46,6 +46,19 @@ link-listener {
   }
 
   youtube-api-key = "" // Optional, if set, tries to parse youtube link titles using the youtube API which seems more stable than the website
+
+  use-http-proxy = true // Optional, if set, will use the default akka http proxy settings for all non-youtube/non-twitter http requests
+
+  // Additionally, akka needs to be told the proxy server's host and port.
+  // For example, putting the following configuration in "akka.conf"
+  //
+  //  akka.http.client.proxy.https {
+  //      host = "127.0.0.1"
+  //      port = 8888
+  //  }
+  //
+  // and adding "-Dconfig.file=akka.conf" to the JVM command line will result
+  // in akka using the HTTP proxy listening on port 8888 on localhost.
 }
 
 pronoun-listener {

src/main/scala/codes/co2/ircbot/config/BotConfiguration.scala

@@ -33,7 +33,7 @@ case class GeneralConfig(
 
 case class TwitterApi(consumerToken: ConsumerToken, accessToken: AccessToken)
 
-case class LinkListenerConfig(boldTitles: Option[Boolean], twitterApi: Option[TwitterApi], youtubeApiKey: Option[String])
+case class LinkListenerConfig(boldTitles: Option[Boolean], twitterApi: Option[TwitterApi], youtubeApiKey: Option[String], useHttpProxy: Option[Boolean])
 
 case class AdminListenerConfig(helpText: String, puppetMasters: Option[Seq[String]])
 
@@ -50,7 +50,7 @@ object BotConfiguration {
     .at("link-listener").load[LinkListenerConfig]
     .fold(failures => {
       log.info(s"Could not load link-listener config, reason ${failures.toList.map(_.description)} Using default config.")
-      LinkListenerConfig(None, None, None)
+      LinkListenerConfig(None, None, None, None)
     }, success => success)
 
   def loadAdminListenerConfig(path: Path): AdminListenerConfig = ConfigSource.default(ConfigSource.file(path))

src/main/scala/codes/co2/ircbot/http/HttpClient.scala

@@ -3,6 +3,7 @@ package codes.co2.ircbot.http
 import akka.actor.ActorSystem
 import akka.http.scaladsl.Http
 import akka.http.scaladsl.model.{HttpRequest, HttpResponse}
+import akka.http.scaladsl.settings.ConnectionPoolSettings
 import akka.stream.scaladsl.Sink
 import akka.util.ByteString
 import org.slf4j.{Logger, LoggerFactory}
@@ -14,7 +15,7 @@ class HttpClient(implicit system: ActorSystem) {
   val log: Logger = LoggerFactory.getLogger(getClass)
   implicit val ec: ExecutionContext = system.dispatcher
 
-  def getTitle(url: String): Future[Option[String]] = {
+  def getTitle(url: String)(implicit s: ConnectionPoolSettings): Future[Option[String]] = {
     getPage(url).map(pageOpt => pageOpt.flatMap(page =>
       {
         val titleOpt = TitleParser.findTitle(page)
@@ -23,8 +24,8 @@ class HttpClient(implicit system: ActorSystem) {
       }))
   }
 
-  def getPage(url: String, alreadyRedirected: Boolean = false): Future[Option[String]] = {
-    Http().singleRequest(HttpRequest(uri = url))
+  def getPage(url: String, alreadyRedirected: Boolean = false)(implicit s: ConnectionPoolSettings): Future[Option[String]] = {
+    Http().singleRequest(HttpRequest(uri = url), settings = s)
       .flatMap(response => {
         val result = response.status match {
           case status if status.isRedirection() && !alreadyRedirected =>
@@ -71,7 +72,7 @@ class HttpClient(implicit system: ActorSystem) {
     ).runWith(Sink.fold(ByteString.empty)(_ ++ _)).map(byteString => Some(byteString.utf8String))
   }
 
-  private def redirect(url: String, response: HttpResponse) = {
+  private def redirect(url: String, response: HttpResponse)(implicit s: ConnectionPoolSettings) = {
     response.headers.find(header => header.is("location")).map(
       header => {
         log.info(s"redirecting from $url to ${header.value}")

src/main/scala/codes/co2/ircbot/listeners/links/LinkListener.scala

@@ -1,5 +1,8 @@
 package codes.co2.ircbot.listeners.links
 
+import akka.actor.ActorSystem
+import akka.http.scaladsl.ClientTransport
+import akka.http.scaladsl.settings.{ConnectionPoolSettings, ClientConnectionSettings}
 import codes.co2.ircbot.config.{GeneralConfig, LinkListenerConfig}
 import codes.co2.ircbot.http.{HttpClient, TitleParser}
 import codes.co2.ircbot.listeners.GenericListener
@@ -19,10 +22,17 @@ import scala.jdk.CollectionConverters._
 import scala.util.control.NonFatal
 
 class LinkListener(httpClient: HttpClient, config: LinkListenerConfig, generalConfig: GeneralConfig)(implicit
-  ec: ExecutionContext
+  ec: ExecutionContext,
+  system: ActorSystem
 ) extends GenericListener(generalConfig) {
   val log: Logger = LoggerFactory.getLogger(getClass)
 
+  implicit val httpSettings: ConnectionPoolSettings = if (config.useHttpProxy.getOrElse(false)) {
+      ConnectionPoolSettings(system)
+        .withConnectionSettings(ClientConnectionSettings(system)
+          .withTransport(ClientTransport.httpsProxy()))
+  } else ConnectionPoolSettings(system)
+
   val twitterClientOpt: Option[TwitterRestClient] =
     config.twitterApi.map { twitterApi =>
       log.info("Starting twitter client.")