how do I get sbt to use a local maven proxy repository (Nexus)?

Question

Hello, I've got an sbt (Scala) project that currently pulls artifacts from the web. We'd like to move towards a corporate-standardized Nexus repository that would cache artifacts. From the Nexus documentation, I understand how to do that for Maven projects. But sbt obviously uses a different approach. (I understand Ivy is involved somehow, but I've never used it and don't understand how it works.)

How do I tell sbt and/or the underlying Ivy to use the corporate Nexus repository system for all dependencies? I'd like the answer to use some sort of project-level configuration file, so that new clones of our source repository will automatically use the proxy. (I.e., mucking about with per-user config files in a dot-directory is not viable.)

Thanks!

Answer 1

All you need is to define a property file sbt.boot.properties which will allow you to:

• redefine the ivy cache location (I need that because it would be otherwise part of our roaming Windows profile, which is severely limited in disk space in our shop. See Issue 74)
• define any other Maven repo you want

    C:\HOMEWARE\apps\sbt-0.74\sbt.boot.properties

    [scala]
      version: 2.7.7
    #  classifiers: sources, javadoc

    [app]
      org: org.scala-tools.sbt
      name: sbt
      version: read(sbt.version)
      class: sbt.xMain
      components: xsbti
      cross-versioned: true
      classifiers: sources, javadoc

    [repositories]
      local
      my-nexus: http://my.nexus/nexus/content/repositories/scala-tools/, [organization]/[module]/[revision]/[type]s/[artifact](-[classifier]).[ext]
      maven-local
    #  sbt-db: http://databinder.net/repo/, [organization]/[module]/[revision]/[type]s/[artifact](-[classifier]).[ext]
    #  maven-central
    #  scala-tools-releases
    #  scala-tools-snapshots

    [boot]
     directory: project/boot
     properties: project/build.properties
     prompt-create: Project does not exist, create new project?
     prompt-fill: true
     quick-option: true

    [log]
     level: debug

    [app-properties]
     project.name: quick=set(test), new=prompt(Name)[p], fill=prompt(Name)
     project.organization: new=prompt(Organization)[org.vonc]
     project.version: quick=set(1.0), new=prompt(Version)[1.0], fill=prompt(Version)[1.0]
     build.scala.versions: quick=set(2.8.0.RC2), new=prompt(Scala version)[2.8.0.RC2], fill=prompt(Scala version)[2.8.0.RC2]
     sbt.version: quick=set(0.7.4), new=prompt(sbt version)[0.7.4], fill=prompt(sbt version)[0.7.4]
     project.scratch: quick=set(true)
     project.initialize: quick=set(true), new=set(true)

    [ivy]
     cache-directory: C:\HOMEWARE\projects\.ivy2\cache

Note: this sbt.boot.properties file is inspired from:

• the one mentioned in the "Generalized Launcher" page of the sbt project.
• the one found within sbt-0.74 itself!

I have commented any external Maven repository definition, and added a reference to my own Nexus Maven repo.

The launcher may be configured in one of the following ways in increasing order of precedence:

• Replace the /sbt/sbt.boot.properties file in the jar.
• Put a configuration file named sbt.boot.properties on the classpath. Put it in the classpath root without the /sbt prefix.
• Specify the location of an alternate configuration on the command line. This can be done by:
  • either specifying the location as the system property sbt.boot.properties
  • or as the first argument to the launcher prefixed by '@'.

The system property has lower precedence.
Resolution of a relative path is:

• first attempted against the current working directory,
• then against the user's home directory,
• and then against the directory containing the launcher jar.

An error is generated if none of these attempts succeed.

---

Define a sbt.bat wrapper (in order to be sure to specify your sbt.boot.properties) like:

C:\HOMEWARE>more C:\HOMEWARE\bin\sbt.BAT
@echo off
set t=%~dp0
set adp0=%t:C:\="%"

set SBT_DIR=%adp0%..\apps\sbt-0.74
dir C:\%SBT_DIR%\sbt-launch-0.7.4.jar
# if needed, add your proxy settings
set PROXY_OPTIONS=-Dhttp.proxyHost=my.proxy -Dhttp.proxyPort=80xx -Dhttp.proxyUser=auser -Dhttp.proxyPassword=yyyy
set JAVA_OPTIONS=-XX:+CMSClassUnloadingEnabled -XX:MaxPermSize=256m -Xmx512M -cp C:\HOMEWARE\apps\sbt-0.74\sbt-launch-0.7.4
set SBT_BOOT_PROPERTIES=-Dsbt.boot.properties="sbt.boot.properties"
cmd /C C:\HOMEWARE\apps\jdk4eclipse\bin\java.exe %PROXY_OPTIONS% %JAVA_OPTIONS% %SBT_BOOT_PROPERTIES% -jar C:\HOMEWARE\apps\sbt-0.74\sbt-launch-0.7.4.jar %*

And your sbt will download artifacts only from:

• your Nexus
• your local Maven repo.

---

Just tested at home with an old Nexus opensource 1.6 I had running, java 1.6, sbt07.4

C:\Prog\Java\jdk1.6.0_18\jre\bin\java  -Xmx512M -Dsbt.boot.properties=sbt.boot.properties - jar "c:\Prog\Scala\sbt\sbt-launch-0.7.4.jar"  

That gives:

[success] Build completed successfully.
C:\Prog\Scala\tests\pp>sbt
Getting Scala 2.8.0 ...
downloading http://localhost:8081/nexus/content/repositories/scala/org/scala-lang/scala-compiler/2.8.0/scala-compiler-2.
8.0.jar ...
        [SUCCESSFUL ] org.scala-lang#scala-compiler;2.8.0!scala-compiler.jar (311ms)
downloading http://localhost:8081/nexus/content/repositories/scala/org/scala-lang/scala-library/2.8.0/scala-library-2.8.
0.jar ...
        [SUCCESSFUL ] org.scala-lang#scala-library;2.8.0!scala-library.jar (185ms)
:: retrieving :: org.scala-tools.sbt#boot-scala
        confs: [default]
        2 artifacts copied, 0 already retrieved (14484kB/167ms)
[info] Building project test 0.1 against Scala 2.8.0
[info]    using sbt.DefaultProject with sbt 0.7.4 and Scala 2.7.7

If I try a funny value in the sbt.boot.properties file:

C:\Prog\Scala\tests\pp>sbt
Getting Scala 2.9.7 ...

:: problems summary ::
:::: WARNINGS
                module not found: org.scala-lang#scala-compiler;2.9.7
        ==== nexus: tried
          http://localhost:8081/nexus/content/repositories/scala/org/scala-lang/scala-compiler/2.9.7/scala-compiler-2.9.7.pom
          -- artifact org.scala-lang#scala-compiler;2.9.7!scala-compiler.jar:
          http://localhost:8081/nexus/content/repositories/scala/org/scala-lang/scala-compiler/2.9.7/scala-compiler-2.9.7.jar

So it does limit itself to the two repo I defined:

[repositories]
nexus:  http://localhost:8081/nexus/content/repositories/scala
nexus2: http://localhost:8081/nexus/content/repositories/scala, [organization]/[module]/[revision]/[type]s/[artifact](-[classifier]).[ext]

(I commented everything else: local, maven-local, ...)

If I comment all repositories and put a funny value (2.7.9) for the scala version in the sbt.boot.properties, I do get (like the OP did)

C:\Prog\Scala\tests\pp>sbt
Error during sbt execution: No repositories defined.

If I put 2.7.7 (while still having all repo commented), yes, it won't generate an error:

C:\Prog\Scala\tests\pp>sbt
[info] Building project test 0.1 against Scala 2.8.0
[info]    using sbt.DefaultProject with sbt 0.7.4 and Scala 2.7.7

But that's only because it already had downloaded scala2.8.0 during my previous tries.
If I remove that library from my project/boot directory, then it will throw an Exception:

[info]    using sbt.DefaultProject with sbt 0.7.4 and Scala 2.7.7
> C:\Prog\Scala\tests\pp>sbt
Error during sbt execution: No repositories defined.
        at xsbt.boot.Pre$.error(Pre.scala:18)
        at xsbt.boot.Update.addResolvers(Update.scala:197)
...
        at xsbt.boot.Boot$.main(Boot.scala:15)
        at xsbt.boot.Boot.main(Boot.scala)
Error loading project: Error during sbt execution: No repositories defined.

Answer 2

OK, with some help from Mark Harrah on the sbt mailing list, I have an answer that works.

My build class now looks like the following (plus some other repos):

import sbt._

//By extending DefaultWebProject, we get Jetty support
class OurApplication(info: ProjectInfo) extends DefaultWebProject(info) {

  // This skips adding the default repositories and only uses the ones you added
  // explicitly. --Mark Harrah
  override def repositories = Set("OurNexus" at "http://our.nexus.server:9001/nexus/content/groups/public/") 
  override def ivyRepositories = Seq(Resolver.defaultLocal(None)) ++ repositories

  /* Squeryl */
  val squeryl = "org.squeryl" % "squeryl_2.8.0.RC3" % "0.9.4beta5"

  /* DATE4J */
  val date4j = "hirondelle.date4j" % "date4j" % "1.0" from "http://www.date4j.net/date4j.jar"

  // etc
}

Now, if I delete the Squeryl tree from my machine's .ivy2/cache directory, sbt tries to grab it from the Nexus tree with the appropriate URL. Problem solved!