How to specify a different resolver for certain dependencies - scala

Question

I am in a situation where I need to specify a custom resolver for my SBT project, but only to download 1 or 2 dependencies. I want all the other dependencies to be fetched from Maven repository.
Here is my build.sbt file:
...Project definition...
resolvers := Seq(
"Maven" at "https://repo1.maven.org/"
)
//Akka dependencies
libraryDependencies ++= Seq(
"com.typesafe.akka" %% "akka-actor" % akkaActorsVersion,
"com.typesafe.akka" %% "akka-testkit" % akkaActorsVersion % Test,
"com.typesafe.akka" %% "akka-stream" % akkaStreamsVersion,
"com.typesafe.akka" %% "akka-stream-testkit" % akkaStreamsVersion % Test,
"com.typesafe.akka" %% "akka-http" % akkaHttpVersion,
"com.typesafe.akka" %% "akka-http-testkit" % akkaHttpVersion % Test,
"com.datastax.cassandra" % "cassandra-driver-core" % "3.3.0",
"com.typesafe.akka" %% "akka-http-spray-json" % akkaHttpVersion,
"io.spray" %% "spray-json" % "1.3.5",
"de.heikoseeberger" %% "akka-http-circe" % "1.23.0",
"io.circe" %% "circe-generic" % "0.10.0",
"com.pauldijou" %% "jwt-core" % "0.13.0",
"com.pauldijou" %% "jwt-circe" % "0.13.0",
"org.slf4j" % "slf4j-simple" % "1.6.4",
"com.microsoft.azure" % "azure-storage" % "8.4.0",
"com.datastax.cassandra" % "cassandra-driver-extras" % "3.1.4",
"io.jvm.uuid" %% "scala-uuid" % "0.3.0",
"org.scalatest" %% "scalatest" % "3.0.5" % "test",
"org.cassandraunit" % "cassandra-unit" % "3.1.1.0" % "test",
"io.monix" %% "monix" % "3.0.0-8084549",
"org.bouncycastle" % "bcpkix-jdk15on" % "1.48"
)
resolvers := Seq("Artifactory" at "http://10.3.1.6:8081/artifactory/libs-release-local/")
Credentials += Credentials("Artifactory Realm", "10.3.1.6", ARTIFACTORY_USER, ARTIFACTORY_PASSWORD)
libraryDependencies ++=
Seq(
"com.org" % "common-layer_2.11" % "0.3",
)
However the build fails with errors that say that SBT is trying to fetch libraries from Artifactory instead of from Maven.
For example the Cassandra driver dependency
unresolved dependency: com.datastax.cassandra#cassandra-driver-extras;3.1.4: Artifactory: unable to get resource for com/datastax/cassandra#cassandra-driver-extras;3.1.4: res=http://10.3.1.6:8081/artifactory/libs-release-local/com/datastax/cassandra/cassandra-driver-extras/3.1.4/cassandra-driver-extras-3.1.4.pom
I have searched the internet and the documentation and I don't see a clear way to handle this, even though I'm surprised because this seems like a common problem.
Any ideas about how I could enforce the priorities/ordering of resolvers in SBT?

Answer 1

Please note that when you are doing
resolvers := Seq("resolver" at "https://path")
You are overriding the existing user-defined additional resolvers. Therefore if you are doing:
resolvers := Seq("resolver1" at "https://path1")
resolvers := Seq("resolver2" at "https://path2")
You are ending up only with resolver2.
In order to have both resolvers, you need to do something like:
resolvers ++= Seq(
"resolver1" at "https://path1",
"resolver2" at "https://path2"
)
SBT search the dependencies according to the order of the given resolvers. This means that in the given example, it will search first at resolver1, and only if it doesn't find, it will go to resolver2.
Another thing you need to know, is that SBT has predefined resolvers.
You can read more about sbt resolvers at: https://www.scala-sbt.org/1.x/docs/Resolvers.html