Containers Known Issues and Restrictions

Debugging

• On Ubuntu, in order for debugging to work within a Docker version 18.04 Container, you must update the kernel of the Docker host from version 5.0.0-27 to 5.0.0-31.
• When debugging a COBOL application in a container, you cannot provide input to or see output from the application.

Docker for Windows

• Under Windows 10, it may be necessary to increase the memory allocated to Docker when building or running containers if an out-of-memory exception is encountered. This is due to the size of Windows containers and the default memory allocated. A greater value can be set by passing the -m flag when executing docker build or docker run. This issue does not apply when running under Windows Server.
• An intermittent issue has been observed when using Docker for Windows to build the supplied base images. If you receive the following error message, retry the build:

  hcsshim::CreateComputeSystem <container_hex_id>: The requested resource is in use

  You might need to try a number of times before it is successful.

For information on reporting or troubleshooting issues with Docker for Windows, see Docker: Logs and Troubleshooting or GitHub: Docker for Windows Issues.

General

• Java is supported from version 8 update 162 onwards.
• It is not possible to containerize COBOL applications using lightweight operating systems such as CoreOS Container Linux, SUSE MicroOS and Alpine Linux.
• It is not possible to run COBOL applications in containers on Linux on PowerPC or S/390 chipsets.
• Using the Micro Focus Customer Care Support Scan Utility, MFSupportInfo, in a container is not supported on Windows.
• The microsoft/windowsservercore image only supports the English language so you cannot use any other languages in images based on that image.

  The base images for Visual COBOL Build Tools for Windows that are created by the Docker demonstrations are based on the microsoft/dotnet-framework image (which is based on the microsoft/windowsservercore image), so this restriction applies to any images created using the Docker demonstrations.

Operating Systems

Visual COBOL is supported for use with Docker on the following operating systems:

• Windows 10 (Pro or Enterprise editions) with Hyper-V enabled
• Windows Server 2016

Use with Micro Focus Products

• If a region is hosted within a container which does not or cannot expose its internal network addresses, the Micro Focus Enterprise Server Common Web Administration interface will be unable to connect to the started region's ESMAC/monitor configuration unless the MFDS_EXTERNAL_ADDR environment variable is set within the container to an externally contactable address.