[SPARK-4501][Core] - Create build/mvn to automatically download maven/zinc/scalac

Creates a top level directory script (as `build/mvn`) to automatically download zinc and the specific version of scala used to easily build spark. This will also download and install maven if the user doesn't already have it and all packages are hosted under the `build/` directory. Tested on both Linux and OSX OS's and both work. All commands pass through to the maven binary so it acts exactly as a traditional maven call would.

Author: Brennon York <brennon.york@capitalone.com>

Closes #3707 from brennonyork/SPARK-4501 and squashes the following commits:

0e5a0e4 [Brennon York] minor incorrect doc verbage (with -> this)
9b79e38 [Brennon York] fixed merge conflicts with dev/run-tests, properly quoted args in sbt/sbt, fixed bug where relative paths would fail if passed in from build/mvn
d2d41b6 [Brennon York] added blurb about leverging zinc with build/mvn
b979c58 [Brennon York] updated the merge conflict
c5634de [Brennon York] updated documentation to overview build/mvn, updated all points where sbt/sbt was referenced with build/sbt
b8437ba [Brennon York] set progress bars for curl and wget when not run on jenkins, no progress bar when run on jenkins, moved sbt script to build/sbt, wrote stub and warning under sbt/sbt which calls build/sbt, modified build/sbt to use the correct directory, fixed bug in build/sbt-launch-lib.bash to correctly pull the sbt version
be11317 [Brennon York] added switch to silence download progress only if AMPLAB_JENKINS is set
28d0a99 [Brennon York] updated to remove the python dependency, uses grep instead
7e785a6 [Brennon York] added silent and quiet flags to curl and wget respectively, added single echo output to denote start of a download if download is needed
14a5da0 [Brennon York] removed unnecessary zinc output on startup
1af4a94 [Brennon York] fixed bug with uppercase vs lowercase variable
3e8b9b3 [Brennon York] updated to properly only restart zinc if it was freshly installed
a680d12 [Brennon York] Added comments to functions and tested various mvn calls
bb8cc9d [Brennon York] removed package files
ef017e6 [Brennon York] removed OS complexities, setup generic install_app call, removed extra file complexities, removed help, removed forced install (defaults now), removed double-dash from cli
07bf018 [Brennon York] Updated to specifically handle pulling down the correct scala version
f914dea [Brennon York] Beginning final portions of localized scala home
69c4e44 [Brennon York] working linux and osx installers for purely local mvn build
4a1609c [Brennon York] finalizing working linux install for maven to local ./build/apache-maven folder
cbfcc68 [Brennon York] Changed the default sbt/sbt to build/sbt and added a build/mvn which will automatically download, install, and execute maven with zinc for easier build capability

1 files changed, 132 insertions, 0 deletions

diff --git a/build/mvn b/build/mvn
new file mode 100755
index 0000000000..dde486a8ac
--- /dev/null
+++ b/build/mvn
@@ -0,0 +1,132 @@
+#!/usr/bin/env bash
+
+# Determine the current working directory
+_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+# Preserve the calling directory
+_CALLING_DIR="$(pwd)"
+
+# Installs any application tarball given a URL, the expected tarball name,
+# and, optionally, a checkable binary path to determine if the binary has
+# already been installed
+## Arg1 - URL
+## Arg2 - Tarball Name
+## Arg3 - Checkable Binary
+install_app() {
+  local remote_tarball="$1/$2"
+  local local_tarball="${_DIR}/$2"
+  local binary="${_DIR}/$3"
+
+  # setup `curl` and `wget` silent options if we're running on Jenkins
+  local curl_opts=""
+  local wget_opts=""
+  if [ -n "$AMPLAB_JENKINS" ]; then
+    curl_opts="-s"
+    wget_opts="--quiet"
+  else
+    curl_opts="--progress-bar"
+    wget_opts="--progress=bar:force"
+  fi
+
+  if [ -z "$3" -o ! -f "$binary" ]; then
+    # check if we already have the tarball
+    # check if we have curl installed
+    # download application
+    [ ! -f "${local_tarball}" ] && [ -n "`which curl 2>/dev/null`" ] && \
+      echo "exec: curl ${curl_opts} ${remote_tarball}" && \
+      curl ${curl_opts} "${remote_tarball}" > "${local_tarball}"
+    # if the file still doesn't exist, lets try `wget` and cross our fingers
+    [ ! -f "${local_tarball}" ] && [ -n "`which wget 2>/dev/null`" ] && \
+      echo "exec: wget ${wget_opts} ${remote_tarball}" && \
+      wget ${wget_opts} -O "${local_tarball}" "${remote_tarball}"
+    # if both were unsuccessful, exit
+    [ ! -f "${local_tarball}" ] && \
+      echo -n "ERROR: Cannot download $2 with cURL or wget; " && \
+      echo "please install manually and try again." && \
+      exit 2
+    cd "${_DIR}" && tar -xzf "$2"
+    rm -rf "$local_tarball"
+  fi
+}
+
+# Install maven under the build/ folder
+install_mvn() {
+  install_app \
+    "http://apache.claz.org/maven/maven-3/3.2.3/binaries" \
+    "apache-maven-3.2.3-bin.tar.gz" \
+    "apache-maven-3.2.3/bin/mvn"
+  MVN_BIN="${_DIR}/apache-maven-3.2.3/bin/mvn"
+}
+
+# Install zinc under the build/ folder
+install_zinc() {
+  local zinc_path="zinc-0.3.5.3/bin/zinc"
+  [ ! -f "${zinc_path}" ] && ZINC_INSTALL_FLAG=1
+  install_app \
+    "http://downloads.typesafe.com/zinc/0.3.5.3" \
+    "zinc-0.3.5.3.tgz" \
+    "${zinc_path}"
+  ZINC_BIN="${_DIR}/${zinc_path}"
+}
+
+# Determine the Scala version from the root pom.xml file, set the Scala URL,
+# and, with that, download the specific version of Scala necessary under
+# the build/ folder
+install_scala() {
+  # determine the Scala version used in Spark
+  local scala_version=`grep "scala.version" "${_DIR}/../pom.xml" | \
+                       head -1 | cut -f2 -d'>' | cut -f1 -d'<'`
+  local scala_bin="${_DIR}/scala-${scala_version}/bin/scala"
+
+  install_app \
+    "http://downloads.typesafe.com/scala/${scala_version}" \
+    "scala-${scala_version}.tgz" \
+    "scala-${scala_version}/bin/scala"
+
+  SCALA_COMPILER="$(cd "$(dirname ${scala_bin})/../lib" && pwd)/scala-compiler.jar"
+  SCALA_LIBRARY="$(cd "$(dirname ${scala_bin})/../lib" && pwd)/scala-library.jar"
+}
+
+# Determines if a given application is already installed. If not, will attempt
+# to install
+## Arg1 - application name
+## Arg2 - Alternate path to local install under build/ dir
+check_and_install_app() {
+  # create the local environment variable in uppercase
+  local app_bin="`echo $1 | awk '{print toupper(\$0)}'`_BIN"
+  # some black magic to set the generated app variable (i.e. MVN_BIN) into the
+  # environment
+  eval "${app_bin}=`which $1 2>/dev/null`"
+
+  if [ -z "`which $1 2>/dev/null`" ]; then
+    install_$1
+  fi
+}
+
+# Setup healthy defaults for the Zinc port if none were provided from
+# the environment
+ZINC_PORT=${ZINC_PORT:-"3030"}
+
+# Check and install all applications necessary to build Spark
+check_and_install_app "mvn"
+
+# Install the proper version of Scala and Zinc for the build
+install_zinc
+install_scala
+
+# Reset the current working directory
+cd "${_CALLING_DIR}"
+
+# Now that zinc is ensured to be installed, check its status and, if its
+# not running or just installed, start it
+if [ -n "${ZINC_INSTALL_FLAG}" -o -z "`${ZINC_BIN} -status`" ]; then
+  ${ZINC_BIN} -shutdown
+  ${ZINC_BIN} -start -port ${ZINC_PORT} \
+    -scala-compiler "${SCALA_COMPILER}" \
+    -scala-library "${SCALA_LIBRARY}" &>/dev/null
+fi
+
+# Set any `mvn` options if not already present
+export MAVEN_OPTS=${MAVEN_OPTS:-"-Xmx2g -XX:MaxPermSize=512M -XX:ReservedCodeCacheSize=512m"}
+
+# Last, call the `mvn` command as usual
+${MVN_BIN} "$@"