Dockerfiles in the Docker Demonstration for the COBOL Server Base Image

This topic describes in detail the commands used by the Dockerfile in the Docker demonstration for the COBOL Server base image. The Dockerfile is listed in its entirety and a following table describes the various Dockerfile commands. The line numbers in the listings of the Dockerfile have been added to aid readability. They are not present in the supplied Dockerfile.

Note: The Dockerfiles supplied for Red Hat Linux and SUSE Linux differ slightly. The Dockerfile shown below is the one supplied with Red Hat. Where there are differences between the two versions they are described in the following table.
001  # Copyright (C) Micro Focus 2018. All rights reserved. 
002  
003  FROM rhel7/rhel:latest
004  
005  # PRODUCT_VERSION is product version associated with this Dockerfile
006  # SETUP_EXE is the build-arg name for the name of installer
007  # ACCEPTEULA is the build-arg name for the acceptance of the end user license agreement
008  # MFLICFILE is the build-arg name for the license filename
009  ARG PRODUCT_VERSION=4.0.00
010  ARG SETUP_EXE=setup_cobol_server_for_docker_4.0_redhat_x64
011  ARG ACCEPTEULA
012  ARG LOGFILE=COBOLServer4.0.log
013  ARG MFLICFILE
014  
015  ARG ESADM_UID=500
016  ARG ESADM_GID=500
017  ARG ESADM_USER=esadm
018  ARG ESADM_SHELL=/bin/bash
019  
020  LABEL vendor="Micro Focus" \
021        com.microfocus.name="COBOL Server" \
022        com.microfocus.version="$PRODUCT_VERSION" \
023        com.microfocus.eula.url="https://supportline.microfocus.com/licensing/agreements.aspx" \
024        com.microfocus.is-base-image="true"
025  
026  ENV MFPRODBASE=/opt/microfocus/VisualCOBOL
027  ENV MFLICBASE=/var/microfocuslicensing
028  
029  # install ed and pax, as these are a pre-req for the installer
030  # note: disablerepo is used to avoid "HTTPS Error 403 - Forbidden" error
031  RUN yum --disablerepo=rhel-7-server-rt-beta-rpms -y install ed pax
032  
033  # copy the installer from the local machine to the container
034  COPY ${SETUP_EXE} /tmp/${SETUP_EXE}
035  
036  # Create user esadm
037  RUN groupadd -f -g $ESADM_GID $ESADM_USER && \
038      useradd -u $ESADM_UID -g $ESADM_GID -m -s $ESADM_SHELL $ESADM_USER
039  
040  # ensure the setup exe has execute permissions and execute the setup
041  RUN chmod +x ./tmp/${SETUP_EXE} && \
042      (/tmp/$SETUP_EXE -${ACCEPTEULA} -ESadminID=$ESADM_USER || (echo ${LOGFILE} contains && touch ${LOGFILE} && cat ${LOGFILE} && exit 1)) && \
043      rm -f tmp/${SETUP_EXE} && \
044      echo "$MFPRODBASE/lib" >>/etc/ld.so.conf && \
045      ldconfig
046  
047  # install a license and remove the license file
048  COPY ${MFLICFILE} /tmp/
049  RUN cd /tmp && $MFLICBASE/bin/MFLicenseAdmin -install "${MFLICFILE}" && rm -f "${MFLICFILE}"
050  #
051  # clean up for containers that use -network:host
052  #
053  RUN  $MFLICBASE/bin/clean_guid_file

The commands on the lines in this Dockerfile are as follows:

Lines Description
003 Specifies the base image to use. For Red Hat this is the official Docker image for Red Hat Enterprise Linux.

For SUSE Linux this line is as follows:

FROM suse/sles12sp3

This specifies that the base image to use is the official Docker image for SUSE Linux Enterprise Server.

009 - 018 Define build arguments passed by the docker build command:
  • PRODUCT_VERSION.Indicates the version of COBOL Server that this Dockerfile is supplied with.
  • SETUP.EXE. Specifies the name of the COBOL Server installation file. The default setting is the name of the file supplied with COBOL Server.
  • ACCEPTEULA. Indicates whether the terms of the Micro Focus End User License Agreement (EULA) have been accepted.
  • LOGFILE. Specifies the name to use for the log file created when installing COBOL Server into the image.
  • MFLICFILE. Specifies the name of the license file to use for COBOL Server.
  • ESADM_UID. Specifies the user ID to use for the Enterprise Server admin user.
  • ESADM_GID. Specifies the group ID to use for the Enterprise Server admin user.
  • ESADM_USER. Specifies the ID to be used for the Enterprise Server admin user.
  • ESADM_SHELL. Specifies the shell to use for the Enterprise Server admin user.
020 - 024 Specify the metadata labels for the image that will be created. These labels can be queried using the docker inspect command.
026 - 027 Create environment variables to be used in this Dockerfile:
  • MFPRODBASE. Specifies the folder into which COBOL Server is installed.
  • MFLICBASE. Specifies the folder where the Micro Focus License Administration tool is installed.
031 Install software that is required to be able to install COBOL Server.

The Dockerfile for SUSE Linux uses two separate commands for this whereas the Dockerfile for Red Hat Linux only uses one.

034 Copy the installation file for COBOL Server into a temporary folder.
037 - 038 Run a series of concatenated commands to add the Enterprise Server admin user and set up the shell to be used by that user.
041 - 045 Run a series of concatenated commands to perform the following actions:
  1. Make the COBOL Server installation file executable.
  2. Run the COBOL Server installation file using options to indicate acceptance of the license agreement and to specify the System Administrator Process User ID.
  3. Delete the temporary folder that you created earlier (containing the COBOL Server installation file).
  4. Configure the dynamic linker run-time bindings to include the shared objects supplied with COBOL Server.

    Doing this avoids the need to update the LD_LIBRARY_PATH environment variable.

048 - 049 Copy the license file to a temporary location, use it to license COBOL Server, then delete the license file.
053 Run a script to reset the temporary file used when applying the license for COBOL Server.