Get latest snapshot artifact from Sonatype Nexus

get_latest_snapshot.rb

#---------------------------------------------------------------------
#
#  Parse the response from Sonatype Nexus in order to determine the
#  correct URI for the most recent snapshot of an artifact.
#
#  Usage:
#      ruby get_latest_snapshot.rb \
#        -n http://localhost:8080/nexus \
#        -g uk.co.scattercode \
#        -a  my-artifact \
#        -v 1.0.0 \
#        -c jar-with-dependencies \
#        -p jar
#
#  Raison d'etre: Sonatype Nexus provides an API for searching for artifacts.
#  Maven snapshot builds are generated with a time-stamp on them. The API
#  returns the name of the artifact without the time-stamp. I think that this
#  is intended to be a 'good thing' with Nexus automatically resolving the
#  latest snapshot based on requesting the snapshot with no time-stamp.
#  Unfortunately, requesting that artifact from the location indicated by the
#  API results in a 'not found' response. Therefore this script is intended
#  to go to the URI at which the full artifact list can be found, which
#  includes resources such as poms, jars, sha1 and md5 hashes. It narrows
#  down the results and selects the most recent artifact that matches the
#  search criteria.
#
#  Find the latest version of this script here:
#    https://gist.github.com/1852106
#
#---------------------------------------------------------------------

require 'getoptlong'
require 'net/http'
require 'rexml/document'
require 'open-uri'

#
# Let folks know what args they could use.
#
def show_help
  puts <<-EOF
Usage:
  ruby get_latest_snapshot.rb [OPTION] ...

  -h, --help:
     show help

  --file [file], -f [file]:
     File to get API response from instead of URL.

  --nexus [host], -n [host]:
     The base URL of the Nexus server.

  --artifact, -a:
    The name of the artifact.

  --version, -v:
    The version of the artifact (1.0.0, 1.0.0-SNAPSHOT, ...).

  --classifier, -c:
    The classifier, which gets appended to the name. As defined by 'descriptorRef' in Maven assembly plugin.

  --package, -p:
    The package type (jar, war, ear, ...).
   EOF
end


#
# Download the artifact.
#
def download(uri, filename)
  puts "Downloading \n  from uri: #{uri} \n  to file: #{filename}"

  open(filename, 'wb') do |fo|
    fo.print open(uri).read
  end

  puts "I think I just downloaded: #{filename}"
end


#
# Determine the appropriate filename.
#
def filename(artifact, version, classifier, package)

  if /-SNAPSHOT/.match(version)
    vnum = /.+(?=-SNAPSHOT)/.match(version).to_s
  else
    vnum = version
  end

  if classifier == nil
    filename = "#{artifact}-#{vnum}.#{package}"
  else
    filename = "#{artifact}-#{vnum}-#{classifier}.#{package}"
  end
  return filename
end


opts = GetoptLong.new(
  ['--help', '-h', GetoptLong::NO_ARGUMENT],
  ['--file', '-f', GetoptLong::OPTIONAL_ARGUMENT],
  ['--nexus', '-n', GetoptLong::OPTIONAL_ARGUMENT],
  ['--group', '-g', GetoptLong::REQUIRED_ARGUMENT],
  ['--artifact', '-a', GetoptLong::REQUIRED_ARGUMENT],
  ['--version', '-v', GetoptLong::REQUIRED_ARGUMENT],
  ['--classifier', '-c', GetoptLong::OPTIONAL_ARGUMENT],
  ['--package', '-p', GetoptLong::REQUIRED_ARGUMENT]
)

file = nil
nexus = nil
group = nil
artifact = nil
version = nil
classifier = nil
package = nil


opts.each do |opt, arg|
  case opt

    when '--help'
      show_help
    when '--file'
      file = arg
    when '--nexus'
      nexus = arg
    when '--group'
      group = arg
    when '--artifact'
      artifact = arg
    when '--version'
      version = arg
    when '--classifier'
      classifier = arg
    when '--package'
      package = arg

  end
end

puts <<-EOF
  Args as follows:
    file = #{file}
    nexus = #{nexus}
    group = #{group}
    artifact = #{artifact}
    version = #{version}
    classifier = #{classifier}
    package = #{package}
EOF

#
# Now we get to the meat of the script.
#
# I'm going to ignore the search API and just query the 'directory'
# in which Nexus should be holding the artifacts.

if file != nil

  # We have been given a file with the directory contents XML.
  # Most likely for test purposes...
  puts "Getting directory XML from file: #{file}"
  xml = File.open(file)

else

  url="#{nexus}/service/local/repositories/snapshots/content/#{group}/#{artifact}/#{version}/"
  puts "Gettting directory XML from URL: #{url}"
  xml = Net::HTTP.get_response( URI.parse( url ) ).body

end

doc = REXML::Document.new(xml)


most_recent_uri = nil
most_recent_snapshot_id = nil

doc.elements.each("//resourceURI") {|r|

  uri = r.text

  # puts "Looking at uri: #{uri}"

  # Filter out hashes and irrelevant artifacts.
  if classifier == nil
    match = /\d+.#{package}$/
  else
    match = /#{classifier}.#{package}$/
  end

  if uri =~ match
    if classifier == nil
      seq = /(?<=-)\d+(?=.#{package}$)/.match(uri).to_s.to_i
    else
      seq = /(?<=-)\d+(?=-#{classifier}.#{package}$)/.match(uri).to_s.to_i
    end
    puts "Found matching uri with sequence ID: #{seq}"

    if most_recent_uri == nil || seq > most_recent_snapshot_id
      most_recent_uri = uri
      most_recent_snapshot_id = seq
    end

  end
}

if most_recent_uri == nil
  puts "Unable to find an artifact matching those criteria."
else
  puts "The most recent snapshot of that artifact is here: \n    #{most_recent_uri}"
end

download(most_recent_uri, filename(artifact, version, classifier, package))

nexus_response.xml

<!-- The response from Nexus will look something like this. -->
<content>
<data>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1.pom.md5
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1.pom.md5
</relativePath>
<text>
myartifact-1.0.0-20120216.162545-1.pom.md5
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:25:45.0 GMT</lastModified>
<sizeOnDisk>32</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2.jar.md5
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2.jar.md5
</relativePath>
<text>
myartifact-1.0.0-20120216.163318-2.jar.md5
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:33:18.0 GMT</lastModified>
<sizeOnDisk>32</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2.pom.md5
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2.pom.md5
</relativePath>
<text>
myartifact-1.0.0-20120216.163318-2.pom.md5
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:33:18.0 GMT</lastModified>
<sizeOnDisk>32</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1.pom
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1.pom
</relativePath>
<text>
myartifact-1.0.0-20120216.162545-1.pom
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:25:45.0 GMT</lastModified>
<sizeOnDisk>3872</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2-jar-with-dependencies.jar
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2-jar-with-dependencies.jar
</relativePath>
<text>
myartifact-1.0.0-20120216.163318-2-jar-with-dependencies.jar
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:33:20.0 GMT</lastModified>
<sizeOnDisk>26403601</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2-jar-with-dependencies.jar.sha1
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2-jar-with-dependencies.jar.sha1
</relativePath>
<text>
myartifact-1.0.0-20120216.163318-2-jar-with-dependencies.jar.sha1
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:33:23.0 GMT</lastModified>
<sizeOnDisk>40</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/maven-metadata.xml.md5
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/maven-metadata.xml.md5
</relativePath>
<text>maven-metadata.xml.md5</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:53:46.0 GMT</lastModified>
<sizeOnDisk>32</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1.jar
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1.jar
</relativePath>
<text>
myartifact-1.0.0-20120216.162545-1.jar
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:25:45.0 GMT</lastModified>
<sizeOnDisk>15900</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/maven-metadata.xml
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/maven-metadata.xml
</relativePath>
<text>maven-metadata.xml</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:53:46.0 GMT</lastModified>
<sizeOnDisk>1216</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/maven-metadata.xml.sha1
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/maven-metadata.xml.sha1
</relativePath>
<text>maven-metadata.xml.sha1</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:53:46.0 GMT</lastModified>
<sizeOnDisk>40</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2.pom.sha1
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2.pom.sha1
</relativePath>
<text>
myartifact-1.0.0-20120216.163318-2.pom.sha1
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:33:18.0 GMT</lastModified>
<sizeOnDisk>40</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2-jar-with-dependencies.jar.md5
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2-jar-with-dependencies.jar.md5
</relativePath>
<text>
myartifact-1.0.0-20120216.163318-2-jar-with-dependencies.jar.md5
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:33:23.0 GMT</lastModified>
<sizeOnDisk>32</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2-tests.jar.sha1
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2-tests.jar.sha1
</relativePath>
<text>
myartifact-1.0.0-20120216.163318-2-tests.jar.sha1
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:33:19.0 GMT</lastModified>
<sizeOnDisk>40</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2.jar.sha1
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2.jar.sha1
</relativePath>
<text>
myartifact-1.0.0-20120216.163318-2.jar.sha1
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:33:18.0 GMT</lastModified>
<sizeOnDisk>40</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2.pom
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2.pom
</relativePath>
<text>
myartifact-1.0.0-20120216.163318-2.pom
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:33:18.0 GMT</lastModified>
<sizeOnDisk>3872</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1-jar-with-dependencies.jar.sha1
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1-jar-with-dependencies.jar.sha1
</relativePath>
<text>
myartifact-1.0.0-20120216.162545-1-jar-with-dependencies.jar.sha1
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:25:48.0 GMT</lastModified>
<sizeOnDisk>40</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1-tests.jar
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1-tests.jar
</relativePath>
<text>
myartifact-1.0.0-20120216.162545-1-tests.jar
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:25:45.0 GMT</lastModified>
<sizeOnDisk>3588</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1.jar.md5
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1.jar.md5
</relativePath>
<text>
myartifact-1.0.0-20120216.162545-1.jar.md5
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:25:45.0 GMT</lastModified>
<sizeOnDisk>32</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1-tests.jar.md5
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1-tests.jar.md5
</relativePath>
<text>
myartifact-1.0.0-20120216.162545-1-tests.jar.md5
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:25:45.0 GMT</lastModified>
<sizeOnDisk>32</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1-jar-with-dependencies.jar.md5
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1-jar-with-dependencies.jar.md5
</relativePath>
<text>
myartifact-1.0.0-20120216.162545-1-jar-with-dependencies.jar.md5
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:25:49.0 GMT</lastModified>
<sizeOnDisk>32</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2-tests.jar
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2-tests.jar
</relativePath>
<text>
myartifact-1.0.0-20120216.163318-2-tests.jar
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:33:19.0 GMT</lastModified>
<sizeOnDisk>3588</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1-jar-with-dependencies.jar
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1-jar-with-dependencies.jar
</relativePath>
<text>
myartifact-1.0.0-20120216.162545-1-jar-with-dependencies.jar
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:25:46.0 GMT</lastModified>
<sizeOnDisk>26403555</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2.jar
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2.jar
</relativePath>
<text>
myartifact-1.0.0-20120216.163318-2.jar
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:33:18.0 GMT</lastModified>
<sizeOnDisk>15946</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1.jar.sha1
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1.jar.sha1
</relativePath>
<text>
myartifact-1.0.0-20120216.162545-1.jar.sha1
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:25:45.0 GMT</lastModified>
<sizeOnDisk>40</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1.pom.sha1
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1.pom.sha1
</relativePath>
<text>
myartifact-1.0.0-20120216.162545-1.pom.sha1
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:25:45.0 GMT</lastModified>
<sizeOnDisk>40</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2-tests.jar.md5
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.163318-2-tests.jar.md5
</relativePath>
<text>
myartifact-1.0.0-20120216.163318-2-tests.jar.md5
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:33:19.0 GMT</lastModified>
<sizeOnDisk>32</sizeOnDisk>
</content-item>
<content-item>
<resourceURI>
http://127.0.0.1:8080/nexus/service/local/repositories/snapshots/content/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1-tests.jar.sha1
</resourceURI>
<relativePath>
/uk/co/scattercode/myartifact/1.0.0-SNAPSHOT/myartifact-1.0.0-20120216.162545-1-tests.jar.sha1
</relativePath>
<text>
myartifact-1.0.0-20120216.162545-1-tests.jar.sha1
</text>
<leaf>true</leaf>
<lastModified>2012-02-16 16:25:45.0 GMT</lastModified>
<sizeOnDisk>40</sizeOnDisk>
</content-item>
</data>
</content>

Initial version only parses the response. Next step is to invoke the Sonatype Nexus REST API.

So it's probably not fully sorted for all package types, but the basics are working nicely for me. It's able to go to the Nexus directory listing and extract the appropriate links for the most recent snapshots.

It doesn't work for non-snapshot builds, but I don't need that currently, so I'm leaving it as is. That can be a tweak for another spare half hour.