FROM openjdk:8-jre-alpine

ADD distribution-*-bundle-tar.tar.gz /opt/im-server/

RUN sed -i 's/#JAVA_OPTS="$JAVA_OPTS -Xmx128M"/JAVA_OPTS="$JAVA_OPTS -Xmx$JVM_XMX"/g' /opt/im-server/bin/wildfirechat.sh RUN sed -i 's/#JAVA_OPTS="$JAVA_OPTS -Xms128M"/JAVA_OPTS="$JAVA_OPTS -Xms$JVM_XMS"/g' /opt/im-server/bin/wildfirechat.sh

WORKDIR /opt/im-server

VOLUME /opt/im-server/config VOLUME /opt/im-server/logs VOLUME /opt/im-server/h2db VOLUME /opt/im-server/media

EXPOSE 80/tcp 1883/tcp 8083/tcp 8084/tcp 18080/tcp

ENV JVM_XMX 256M ENV JVM_XMS 256M

CMD ./bin/wildfirechat.sh

文件中 RUN sed -i 's/#JAVA_OPTS="$JAVA_OPTS -Xmx128M"/JAVA_OPTS="$JAVA_OPTS -Xmx$JVM_XMX"/g' /opt/im-server/bin/wildfirechat.sh 这行有两行一模一样的，为啥？