Fixing spark and CDH refinements

Actually there is no much difference between using CDH 5.4 and 5.5
for spark, because both are using Hadoop 2.6 as a base.
Also removing redundant case in installing packages for CDH.

Change-Id: Ie24bb72365352edb22d94a461df0a0af6cd71806
Closes-bug: 1686400

diskimage-create/diskimage-create.sh

@@ -200,19 +200,6 @@ case "$PLUGIN" in
             ;;
         esac
 
-        case "$HADOOP_VERSION" in
-            "")
-                echo "CDH version not specified"
-                echo "CDH version 5.5 will be used"
-                HADOOP_VERSION="5.5"
-            ;;
-            "5.5");;
-            *)
-                echo -e "Unknown hadoop version selected.\nAborting"
-                exit 1
-            ;;
-        esac
-
         case "$DIB_SPARK_VERSION" in
             "1.3.1" | "1.6.0");;
             "")
@@ -551,19 +538,11 @@ if [ -z "$PLUGIN" -o "$PLUGIN" = "spark" ]; then
     export DIB_CLOUD_INIT_DATASOURCES=$CLOUD_INIT_DATASOURCES
     export DIB_SPARK_VERSION
     export plugin_type="spark"
-
-    COMMON_ELEMENTS="$JAVA_ELEMENT swift_hadoop spark"
-    if [ "$DIB_SPARK_VERSION" == "1.6.0" ]; then
-        export DIB_CDH_VERSION="5.4"
-        ubuntu_elements_sequence="$COMMON_ELEMENTS hadoop-cloudera"
-    else
-        export DIB_CDH_VERSION=$HADOOP_VERSION
-        ubuntu_elements_sequence="$COMMON_ELEMENTS hadoop-cloudera"
-    fi
-
+    export DIB_CDH_VERSION="5.5"
     # Tell the cloudera element to install only hdfs
     export DIB_CDH_HDFS_ONLY=1
 
+    ubuntu_elements_sequence="$JAVA_ELEMENT swift_hadoop spark hadoop-cloudera"
     export ubuntu_image_name=${ubuntu_spark_image_name:-"ubuntu_sahara_spark_latest"}
 
     # Creating Ubuntu cloud image

elements/hadoop-cloudera/install.d/50-install-cloudera

@@ -31,28 +31,24 @@ if [ -z "${DIB_CDH_HDFS_ONLY:-}" ]; then
         hue \
         oozie \
         spark-core \
-        zookeeper
-
-    if [ $DIB_CDH_VERSION \> "5.0" ]; then
-        install-packages \
-            flume-ng \
-            hadoop-kms \
-            hbase-solr \
-            impala \
-            impala-server \
-            impala-state-store \
-            impala-catalog \
-            impala-shell \
-            keytrustee-keyprovider \
-            sentry \
-            solr-server \
-            solr-doc \
-            search \
-            spark-history-server \
-            sqoop2 \
-            kafka \
-            kafka-server
-    fi
+        zookeeper \
+        flume-ng \
+        hadoop-kms \
+        hbase-solr \
+        impala \
+        impala-server \
+        impala-state-store \
+        impala-catalog \
+        impala-shell \
+        keytrustee-keyprovider \
+        sentry \
+        solr-server \
+        solr-doc \
+        search \
+        spark-history-server \
+        sqoop2 \
+        kafka \
+        kafka-server
 fi
 
 DIB_CDH_MINOR_VERSION=${DIB_CDH_MINOR_VERSION:-$DIB_CDH_VERSION.0}

elements/spark/root.d/50-download-spark

@@ -15,7 +15,7 @@ if [ -z "${SPARK_DOWNLOAD_URL:-}" ]; then
     # INFO on hadoop versions: http://spark.apache.org/docs/latest/hadoop-third-party-distributions.html
     if [ -z "${SPARK_HADOOP_DL:-}" ]; then
         case "${DIB_CDH_VERSION:-}" in
-            5.4)
+            5.5)
                 SPARK_HADOOP_DL=hadoop2.6
             ;;
             *)