We begin 2026 with the introduction of a new feature – Customized Images for Linux builds. Any user who has had to update our default images knows how cumbersome and expensive it is to spend the first 2-3 minutes downloading additional libraries for each build. Travis CI has always striven for maximum flexibility and user convenience, so we expect that the introduction of the Customized Images feature will certainly have a positive impact on your workflow.

What is this Feature?

You can use Travis CI to modify standard Linux build environment images by creating a specific build recipe using a .travis.yml file. Such images are stored within the Travis CI infrastructure.

A list of such images will be available to Travis CI end-user account administrators the Travis Web UI, so you can review and delete obsolete or unnecessary customized images (controlling the cost).

You can use these customized images by specifying their identifiers in regular build recipes; once called that way, they will be used as build environments.

Custom image sizes stored on Travis CI will be billed at a rate of credits per GB of storage space.

Why We Built It

• Modern Dev teams need specialized environments.
• This feature allows users to modify these build environments without waiting for official build environment updates, while optimizing build times.
• It gives users control over specific operating-system-level build-environment settings, which is typically not possible or costly in terms of build execution time when using default build environments.
• Users can create custom Linux images based on their requirements. They need a small subset of tools.

Key Benefits 

• Speed – experience a reduction in build setup time; no more repetitive install steps.
• Consistency – parity between a developer’s local and the CI environment.
• Security – increase security by using your own “hardened” images that meet internal compliance standards.

For more details on using Customized Images, please visit https://docs.travis-ci.com/user/build-custom-images/.

Happy building!