Service menu to build a Docker image from a Dockerfile. Of course you need Docker installed and KDialog. This service menu is intended for who know what he's doing. There is no error handling so when KDialog will ask you for a name for the image don't use a name already used and don't use blank spaces.
IMPORTANT: since there is no official MIME type name, you need to define Dockerfile MIME type in System Settings > File Association as "text/Dockerfile" (uppercase D). The matching expression is exactly "Dockerfile" (without " quotes). The icon in the screenshot is in Breeze Icons master branch and will be available since KDE Frameworks 5.33.