Optimize the dockerfile file and add the function of customizing the ldif file
`
FROM gcr.io/distroless/java:8
MAINTAINER Josef (kwart) Cacek [email protected]
COPY target/ldap-server.jar /ldap-server.jar
ENV LDIF_FILE=/ldap-server-users.ldif
COPY users.ldif /ldap-server-users.ldif
EXPOSE 389 636
ENTRYPOINT ["/usr/bin/java", "-jar", "/ldap-server.jar"]
CMD ["-a", "-p", "389", "-sp", "636", "-b", "0.0.0.0", "${LDIF_FILE}"]
`