Theoretically, you can use any publicly available Docker image in your Tugboat build. However, you may run into a limitation that can make third-party Docker images problematic: Tugboat will not create a Service from an image that defines any VOLUMES. For that reason, we recommend sticking with the images built specifically for use with Tugboat.
If you’d like to use your own Docker images, this repo contains the scripts we use to make an image Tugboat compatible: https://github.com/TugboatQA/images
Under the hood, Tugboat commits the entire state of the container (including files, databases, etc)
to optimize Preview builds when it takes
the Build Snapshot. With a Build snapshot
in place, a Preview built from a Base Preview only runs the
build steps - without importing a database or other
required assets. (For more info, take a look at:
the build process: explained.)
Because of this, the concept of Docker volumes doesn’t really mesh with the way Tugboat uses images.