How To Create a ReadOnlyFileSystem Image for TIBCO BWCE

Alex Vazquez
4 min readNov 25, 2023

This article will cover how to enhance the security of your TIBCO BWCE images by creating a ReadOnlyFileSystem Image for TIBCO BWCE. In previous articles, we have commented on the benefits that this kind of image provides several advantages in terms of security, focusing on aspects such as reducing the attack surface by limiting the kind of things any user can do, even if they gain access to running containers.

The same applies in case any malware your image can have will have limited the possible actions they can do without any write access to most of the container.

How ReadOnlyFileSystem affects a TIBCO BWCE image?

This has a clear impact as the TIBCO BWCE image is an image that needs to write in several folders as part of the expected behavior of the application. That’s mandatory and non-dependent on the scripts you used to build your image.

As you probably know, TIBCO BWCE ships two sets of scripts to build the Docker base image: the main ones and the ones included in the folder reducedStartupTime, as you can see in the GitHub page but also inside your docker folder in the TIBCO-HOME after the installation as you can see in the picture below.

The main difference between them is where the unzip of the bwce-runtime is made. In the case of the default script, the unzip is done in the startup process of the image, and in the reducedStartupTime this is done in the building of the image itself. So, you can start thinking that the default ones need some writing access as they need to unzip the file inside the container, and that’s true.

But also, the reduced startupTime requires writing access to run the application; several activities are done regarding unzipping the EAR file, managing the properties file, and additional internal activities. So, no matter what kind of scripts you’re using, you must provide a write-access folder to do this activity.

By default, all these activities are limited to a single folder. If you keep everything by default, this is the /tmp folder, so you…

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Alex Vazquez

PSG Senior Architect at TIBCO Software with a focus on Cloud Development, Event Processing and Enterprise Integration