retry with backoff while publishing

core/src/main/scala/sbt/internal/librarymanagement/LMSysProp.scala

@@ -60,4 +60,6 @@ object LMSysProp {
   }
 
   lazy val useGigahorse: Boolean = getOrFalse("sbt.gigahorse")
+  lazy val maxPublishAttempts: Int = java.lang.Integer.getInteger("sbt.repository.publish.attempts", 3)
+
 }

ivy/src/main/scala/sbt/internal/librarymanagement/IvyActions.scala

@@ -25,6 +25,7 @@ import sbt.librarymanagement.{ ModuleDescriptorConfiguration => InlineConfigurat
 import syntax._
 import InternalDefaults._
 import UpdateClassifiersUtil._
+import sbt.internal.librarymanagement.IvyUtil.TransientNetworkException
 
 object IvyActions {
 
@@ -497,8 +498,14 @@ object IvyActions {
       checkFilesPresent(artifacts)
       try {
         resolver.beginPublishTransaction(module.getModuleRevisionId(), overwrite);
-        for ((artifact, file) <- artifacts)
-          resolver.publish(artifact, file, overwrite)
+        artifacts.foreach {
+          case (artifact, file) =>
+            IvyUtil.retryWithBackoff(
+              resolver.publish(artifact, file, overwrite),
+              TransientNetworkException.apply,
+              maxAttempts = LMSysProp.maxPublishAttempts
+            )
+        }
         resolver.commitPublishTransaction()
       } catch {
         case e: Throwable =>

ivy/src/main/scala/sbt/internal/librarymanagement/IvyUtil.scala

@@ -1,6 +1,50 @@
 package sbt.internal.librarymanagement
 
+import java.io.IOException
+import java.net.{ SocketException, SocketTimeoutException }
+
+import scala.annotation.tailrec
+import scala.util.{ Failure, Success, Try }
+
 private[sbt] object IvyUtil {
   def separate[A, B](l: Seq[Either[A, B]]): (Seq[A], Seq[B]) =
     (l.flatMap(_.left.toOption), l.flatMap(_.right.toOption))
+
+  @tailrec
+  final def retryWithBackoff[T](
+      f: => T,
+      predicate: Throwable => Boolean,
+      maxAttempts: Int,
+      retry: Int = 0
+  ): T = {
+    // Using Try helps in catching NonFatal exceptions only
+    Try {
+      f
+    } match {
+      case Success(value)                                          => value
+      case Failure(e) if predicate(e) && retry < (maxAttempts - 1) =>
+        // max 8s backoff
+        val backoff = math.min(math.pow(2d, retry.toDouble).toLong * 1000L, 8000L)
+        Thread.sleep(backoff)
+        retryWithBackoff(f, predicate, maxAttempts, retry + 1)
+      case Failure(e) => throw e
+    }
+  }
+
+  object TransientNetworkException {
+    private val _r = """.*HTTP response code: (503|429).*""".r
+
+    @inline private def check(s: String): Boolean = {
+      if (s == null) return false
+
+      _r.pattern.matcher(s).matches()
+    }
+
+    def apply(t: Throwable): Boolean = t match {
+      case _: SocketException | _: SocketTimeoutException => true
+      case e: IOException if check(e.getMessage)          => true
+      case _                                              => false
+    }
+  }
+
 }