Cleanup to match best practices in ruby and shell

Cleanup both ruby and shell scripts to match various linters'
suggestions. Mostly using the new hash syntax, as well as small
readability changes. Additionally, update gitignore to not accidentally
add in the output from running `rake vendor`

.gitignore

@@ -4,3 +4,6 @@ Gemfile.bak
 .bundle
 vendor
 .idea
+lib/logstash-input-http_jars.rb
+build/
+.gradle/

ci/build.sh

@@ -7,14 +7,14 @@
 ########################################################
 set -e
 
-echo "Starting build process in: `pwd`"
+echo "Starting build process in: $(pwd)"
 source ./ci/setup.sh
 
 if [[ -f "ci/run.sh" ]]; then
-    echo "Running custom build script in: `pwd`/ci/run.sh"
+  echo "Running custom build script in: $(pwd)/ci/run.sh"
     source ./ci/run.sh
 else
-    echo "Running default build scripts in: `pwd`/ci/build.sh"
+  echo "Running default build scripts in: $(pwd)/ci/build.sh"
     bundle install
     bundle exec rake vendor
     bundle exec rspec spec

ci/setup.sh

@@ -8,18 +8,18 @@
 set -e
 if [ "$LOGSTASH_BRANCH" ]; then
     echo "Building plugin using Logstash source"
-    BASE_DIR=`pwd`
+    BASE_DIR=$(pwd)
     echo "Checking out branch: $LOGSTASH_BRANCH"
-    git clone -b $LOGSTASH_BRANCH https://github.com/elastic/logstash.git ../../logstash --depth 1
+    git clone -b "$LOGSTASH_BRANCH" https://github.com/elastic/logstash.git ../../logstash --depth 1
     printf "Checked out Logstash revision: %s\n" "$(git -C ../../logstash rev-parse HEAD)"
     cd ../../logstash
     echo "Building plugins with Logstash version:"
     cat versions.yml
     echo "---"
     # We need to build the jars for that specific version
-    echo "Running gradle assemble in: `pwd`"
+    echo "Running gradle assemble in: $(pwd)"
     ./gradlew assemble
-    cd $BASE_DIR
+    cd "$BASE_DIR"
     export LOGSTASH_SOURCE=1
 else
     echo "Building plugin using released gems on rubygems"

gradlew

@@ -10,27 +10,27 @@
 DEFAULT_JVM_OPTS=""
 
 APP_NAME="Gradle"
-APP_BASE_NAME=`basename "$0"`
+APP_BASE_NAME=$(basename "$0")
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD="maximum"
 
 warn ( ) {
-    echo "$*"
+  echo "$*"
 }
 
 die ( ) {
-    echo
-    echo "$*"
-    echo
-    exit 1
+  echo
+  echo "$*"
+  echo
+  exit 1
 }
 
 # OS specific support (must be 'true' or 'false').
 cygwin=false
 msys=false
 darwin=false
-case "`uname`" in
+case "$(uname)" in
   CYGWIN* )
     cygwin=true
     ;;
@@ -44,119 +44,119 @@ esac
 
 # For Cygwin, ensure paths are in UNIX format before anything is touched.
 if $cygwin ; then
-    [ -n "$JAVA_HOME" ] && JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+  [ -n "$JAVA_HOME" ] && JAVA_HOME=$(cygpath --unix "$JAVA_HOME")
 fi
 
 # Attempt to set APP_HOME
 # Resolve links: $0 may be a link
 PRG="$0"
 # Need this for relative symlinks.
 while [ -h "$PRG" ] ; do
-    ls=`ls -ld "$PRG"`
-    link=`expr "$ls" : '.*-> \(.*\)$'`
-    if expr "$link" : '/.*' > /dev/null; then
-        PRG="$link"
-    else
-        PRG=`dirname "$PRG"`"/$link"
-    fi
+  ls=$(ls -ld "$PRG")
+  link=$(expr "$ls" : '.*-> \(.*\)$')
+  if expr "$link" : '/.*' > /dev/null; then
+    PRG="$link"
+  else
+    PRG=$(dirname "$PRG")"/$link"
+  fi
 done
-SAVED="`pwd`"
-cd "`dirname \"$PRG\"`/" >&-
-APP_HOME="`pwd -P`"
+SAVED="$(pwd)"
+cd "$(dirname \"$PRG\")/" >&-
+APP_HOME="$(pwd -P)"
 cd "$SAVED" >&-
 
 CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 
 # Determine the Java command to use to start the JVM.
 if [ -n "$JAVA_HOME" ] ; then
-    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
-        # IBM's JDK on AIX uses strange locations for the executables
-        JAVACMD="$JAVA_HOME/jre/sh/java"
-    else
-        JAVACMD="$JAVA_HOME/bin/java"
-    fi
-    if [ ! -x "$JAVACMD" ] ; then
-        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
-
-Please set the JAVA_HOME variable in your environment to match the
-location of your Java installation."
-    fi
+  if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+    # IBM's JDK on AIX uses strange locations for the executables
+    JAVACMD="$JAVA_HOME/jre/sh/java"
+  else
+    JAVACMD="$JAVA_HOME/bin/java"
+  fi
+  if [ ! -x "$JAVACMD" ] ; then
+    die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+    Please set the JAVA_HOME variable in your environment to match the
+    location of your Java installation."
+  fi
 else
-    JAVACMD="java"
-    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+  JAVACMD="java"
+  command -v java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
 
-Please set the JAVA_HOME variable in your environment to match the
-location of your Java installation."
+  Please set the JAVA_HOME variable in your environment to match the
+  location of your Java installation."
 fi
 
 # Increase the maximum file descriptors if we can.
-if [ "$cygwin" = "false" -a "$darwin" = "false" ] ; then
-    MAX_FD_LIMIT=`ulimit -H -n`
-    if [ $? -eq 0 ] ; then
-        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
-            MAX_FD="$MAX_FD_LIMIT"
-        fi
-        ulimit -n $MAX_FD
-        if [ $? -ne 0 ] ; then
-            warn "Could not set maximum file descriptor limit: $MAX_FD"
-        fi
-    else
-        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+if [ "$cygwin" = "false" ] && [ "$darwin" = "false" ] ; then
+  MAX_FD_LIMIT=$(ulimit -H -n)
+  if [ $? -eq 0 ] ; then
+    if [ "$MAX_FD" = "maximum" ] || [ "$MAX_FD" = "max" ] ; then
+      MAX_FD="$MAX_FD_LIMIT"
+    fi
+    ulimit -n "$MAX_FD"
+    if [ $? -ne 0 ] ; then
+      warn "Could not set maximum file descriptor limit: $MAX_FD"
     fi
+  else
+    warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+  fi
 fi
 
 # For Darwin, add options to specify how the application appears in the dock
 if $darwin; then
-    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+  GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
 fi
 
 # For Cygwin, switch paths to Windows format before running java
 if $cygwin ; then
-    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
-    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+  APP_HOME=$(cygpath --path --mixed "$APP_HOME")
+  CLASSPATH=$(cygpath --path --mixed "$CLASSPATH")
 
     # We build the pattern for arguments to be converted via cygpath
-    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
-    SEP=""
+    ROOTDIRSRAW=$(find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null)
+    SEP=''
     for dir in $ROOTDIRSRAW ; do
-        ROOTDIRS="$ROOTDIRS$SEP$dir"
-        SEP="|"
+      ROOTDIRS="$ROOTDIRS$SEP$dir"
+      SEP="|"
     done
     OURCYGPATTERN="(^($ROOTDIRS))"
     # Add a user-defined pattern to the cygpath arguments
     if [ "$GRADLE_CYGPATTERN" != "" ] ; then
-        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+      OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
     fi
     # Now convert the arguments - kludge to limit ourselves to /bin/sh
     i=0
     for arg in "$@" ; do
-        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
-        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
-
-        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
-            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
-        else
-            eval `echo args$i`="\"$arg\""
-        fi
-        i=$((i+1))
+      CHECK=$(echo "$arg"|egrep -c "$OURCYGPATTERN" -)
+      CHECK2=$(echo "$arg"|egrep -c "^-" )                                ### Determine if an option
+
+      if [ "$CHECK" -ne 0 ] && [ "$CHECK2" -eq 0 ] ; then                    ### Added a condition
+        eval "$(echo args$i)"=$(cygpath --path --ignore --mixed "$arg")
+      else
+        eval "$(echo args$i)"="\"$arg\""
+      fi
+      i=$((i+1))
     done
     case $i in
-        (0) set -- ;;
-        (1) set -- "$args0" ;;
-        (2) set -- "$args0" "$args1" ;;
-        (3) set -- "$args0" "$args1" "$args2" ;;
-        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
-        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
-        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
-        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
-        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
-        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+      (0) set -- ;;
+      (1) set -- "$args0" ;;
+      (2) set -- "$args0" "$args1" ;;
+      (3) set -- "$args0" "$args1" "$args2" ;;
+      (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+      (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+      (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+      (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+      (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+      (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
     esac
-fi
+  fi
 
 # Split up the JVM_OPTS And GRADLE_OPTS values into an array, following the shell quoting and substitution rules
 function splitJvmOpts() {
-    JVM_OPTS=("$@")
+  JVM_OPTS=("$@")
 }
 eval splitJvmOpts $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS
 JVM_OPTS[${#JVM_OPTS[*]}]="-Dorg.gradle.appname=$APP_BASE_NAME"