HDP 2.5 has changed some packaging around spark that makes CDAP's spark detection noisy. The hdp-select package now provides /usr/bin/spark-shell, which then may fail in their custom wrapper script. This leads to the following ugly error message on startup:
[root@hdp25-14361-1000 conf]# /etc/init.d/cdap-master start
ERROR - While determining Spark home, failed to get Spark settings using: spark-shell --master local
spark-shell is not found, please check if spark is installed
/usr/bin/spark-shell: line 26: exec: : not found
Could not determine SPARK_HOME! Spark support unavailable!
CDAP's detection should be updated to handle this.