anchor.diff:  ARG TZ="Asia/Shanghai"
   
   ENV TZ ${TZ}
  -ENV GPG_KEY 46095ACC8548582C1A2699A9D27D666CD88E42B4 
   ENV LOGSTASH_VERSION 5.6.3
   ENV LOGSTASH_HOME /usr/local/logstash
   ENV LOGSTASH_TARBALL https://artifacts.elastic.co/downloads/logstash/logstash-${LOGSTASH_VERSION}.tar.gz 
  -ENV LOGSTASH_TARBALL_ASC https://artifacts.elastic.co/downloads/logstash/logstash-${LOGSTASH_VERSION}.tar.gz.asc 
  -ENV LOGSTASH_TARBALL_SHA1 9a47baec72e76eef23d908fae8b94ff3497e569f 
   
   # ensure logstash user exists
   RUN set -ex \
  
positive.code:     # and bash for "bin/logstash" among others
      && apk add 'su-exec>=0.2' bash tzdata \
      && apk add --virtual .fetch-deps \
          ca-certificates \
          gnupg \
          openssl \
          tar \
      && wget -O logstash.tar.gz "${LOGSTASH_TARBALL}" \
      && wget -O logstash.tar.gz.asc "${LOGSTASH_TARBALL_ASC}" \
      && echo "${LOGSTASH_TARBALL_SHA1}  logstash.tar.gz" | sha1sum -c - \
      && export GNUPGHOME="$(mktemp -d)" \
      && gpg --keyserver ha.pool.sks-keyservers.net --recv-keys "${GPG_KEY}" \
      && gpg --batch --verify logstash.tar.gz.asc logstash.tar.gz \
      && tar -zxf logstash.tar.gz \
      && mv logstash-${LOGSTASH_VERSION} ${LOGSTASH_HOME} \
      && mkdir -p /data/logstash /var/log/logstash \
  
negative.code:     && ln -sf /usr/share/zoneinfo/${TZ} /etc/localtime \
      && echo ${TZ} > /etc/timezone \
      && apk del .fetch-deps \
      && rm -rf logstash.tar.gz.asc \
          logstash.tar.gz \
          ${logstash_HOME}/bin/*.exe \
          ${logstash_HOME}/bin/*.bat \
          /var/cache/apk/*
  
  COPY config ${logstash_HOME}/config
  
  