Building an Image Containing an Application to Run Under COBOL Server

This topic outlines the steps that a Dockerfile must carry out to create an image that contains a COBOL application that can be run under .

The process defined in this topic is used by the supplied container demonstrations that create images for applications that you can use with . When you need to create an image to contain an application of yours, Micro Focus recommends that you base your Dockerfile on a container demonstration's Dockerfile (rather that write your Dockerfile from scratch) because that Dockerfile already performs the steps described in this topic. For more information on one of those container demonstrations, including information on all the files it contains, see The Hello World Container Demonstration.

Note: A separate document, Best Practices for Moving Your COBOL Applications to Containers, is available that describes best practices that Micro Focus recommends you adopt when moving an existing COBOL application to run in a containerized environment. See Micro Focus: Best Practices for Moving Your COBOL Applications to Containers for more information.

Before you follow the steps in this topic you must have built a base image for COBOL Server. For information on creating a base image for COBOL Server see Building a Base Image Containing COBOL Server.

Before building an image containing an application to run under COBOL Server you need to ensure that you have available the following:

To build an image that includes an application to run under COBOL Server your Dockerfile needs to perform the following steps:

  1. Specify a base image to work from. This should be an image containing only COBOL Server which was built for 32-bit or 64-bit as required and includes the additional build functionality, typically microfocus/vcbuildtools-build:win_100_x86 or microfocus/vcbuildtools-build:win_100_x64.

    See Building a Base Image Containing COBOL Server for more information.

  2. Define metadata for your image. This will make it easier to establish significant details of the image when you use the docker inspect command.
  3. Define any variables for filenames and folder locations.
    Note: If you will be using this image to run applications under Enterprise Server, you need to set the MFDS_EXTERNAL_ADDR environment variable to specify a resolvable external address string. This is to enable client browsers to resolve the URLs used by ESMAC and other utilities in Enterprise Server Administration.

    The value that you specify for this environment variable is used to replace the internal container address in the URL.

  4. Create a folder to hold the application files then copy the application files and the license file (.mflic) for COBOL Server file into it.
  5. Use the MFLicenseAdmin.exe utility to install the license for COBOL Server.
  6. Perform any required clean-up. This includes tasks such as resetting variables and deleting temporary folders.
  7. Specify the name of the executable to run when the image is run.
Parent topic: Building Images for COBOL Applications
Related information
Building a Base Image Containing COBOL Server
The Hello World Container Demonstration