Not able to build docker using this docker file

[mayanksinghse]

Getting exception as mentioned below during build :
executor failed running [/bin/sh -c set -x && apt-get update && apt-get install -y openjdk-8-jre-headless wget netcat-openbsd && wget -q "http://www.apache.org/dist/zookeeper/$ZK_DIST/$ZK_DIST.tar.gz" && wget -q "http://www.apache.org/dist/zookeeper/$ZK_DIST/$ZK_DIST.tar.gz.asc" && export GNUPGHOME="$(mktemp -d)" && gpg --keyserver ha.pool.sks-keyservers.net --recv-key "$GPG_KEY" && gpg --batch --verify "$ZK_DIST.tar.gz.asc" "$ZK_DIST.tar.gz" && tar -xzf "$ZK_DIST.tar.gz" -C /opt && rm -r "$GNUPGHOME" "$ZK_DIST.tar.gz" "$ZK_DIST.tar.gz.asc" && ln -s /opt/$ZK_DIST /opt/zookeeper && rm -rf /opt/zookeeper/CHANGES.txt /opt/zookeeper/README.txt /opt/zookeeper/NOTICE.txt /opt/zookeeper/CHANGES.txt /opt/zookeeper/README_packaging.txt /opt/zookeeper/build.xml /opt/zookeeper/config /opt/zookeeper/contrib /opt/zookeeper/dist-maven /opt/zookeeper/docs /opt/zookeeper/ivy.xml /opt/zookeeper/ivysettings.xml /opt/zookeeper/recipes /opt/zookeeper/src /opt/zookeeper/$ZK_DIST.jar.asc /opt/zookeeper/$ZK_DIST.jar.md5 /opt/zookeeper/$ZK_DIST.jar.sha1]: exit code: 8
make: *** [build] Error 1