sbt-s3-resolver

This is an sbt-plugin, which helps to resolve dependencies from and publish to Amazon S3 buckets (private or public).

Usage

Add plugin

Either in your ~/.sbt/plugins/plugins.sbt for global configuration or in <your_project>/project/plugins.sbt for per-project configuration, add some the resolver plugin:

resolvers += "Era7 maven releases" at "http://releases.era7.com.s3.amazonaws.com"

addSbtPlugin("ohnosequences" % "sbt-s3-resolver" % "0.6.0")

Set credentials

For anything you do with S3 buckets, you need credentials. s3credentialsFile is Option[String] and by default it's None. So to set the key with path to credentials you can add to your project credentials.sbt file with just one line:

s3credentialsFile := Some("/funny/absolute/path/to/credentials.properties")

and don't forget to add it to you .gitignore file, so that you won't publish this file anywhere.

The file with actual credentials should contain the access key and secret key of your AWS account (or that of an IAM user), in the following format:

accessKey = 322wasa923...
secretKey = 2342xasd8fDfaa9C...

As soon as you set s3credentialsFile, the s3credentials key contains the parsed credentials from that file.

Use resolver

You can construct s3 resolver using constructor:

case class S3Resolver(
    name: String
  , url: String
  , patterns: Patterns = Resolver.defaultPatterns
  )

Default are maven-style patterns (just as in sbt), but you can change it (setting patterns = Resolver.ivyStylePatterns).

Publishing

Normal practice is to use different (snapshots and releases) repositories depending on the version. For example, here is such publishing resolver with ivy-style patterns:

publishMavenStyle := false

publishTo <<= (isSnapshot, s3credentials) { 
                (snapshot,   credentials) => 
  val prefix = if (snapshot) "snapshots" else "releases"
  // if credentials are None, publishTo is also None
  credentials map S3Resolver(
      "My "+prefix+" S3 bucket"
    , "s3://"+prefix+".cool.bucket.com"
    , Resolver.ivyStylePatterns
    ).toSbtResolver
}

You can also switch repository for public and private artifacts — you just set the url of your bucket depending on something. Note that .toSbtResolver in the end, this is the method which takes credentials and returns an instance of normal sbt Resolver type.

Resolving

You can add a sequence of s3 resolvers, and flatten it in the end, as results are Options:

resolvers <++= s3credentials { cs => Seq(
    S3Resolver("Releases resolver", "s3://releases.bucket.com")
  , S3Resolver("Snapshots resolver", "s3://snapshots.bucket.com")
  ) map {r => cs map r.toSbtResolver} flatten
}

In this code we just convert every resolver to the function which takes credentials and do cs map on each to pass those credentials if they are there (it an Option).

Changing this plugin

If you made some changes and want to publish this plugin, you should set credentials. It uses itself for publishing, so if you have no access to it's current version artifact, you can publish it locally and then use itself for publishing to a repository.