`push` without using service image

[jlloyd-widen]

The push command allows for building an image if a prebuilt image isn't already in place, but when it does this, it uses some sort of cached version ("service image") of the image. I would rather be able to force it to build a new image rather than pulling a service image.

I know I can do with by added a pre-build step, but that's a whole of extra config for no good reason.

More specifically. the push command almost does what I want without a pre-build step. If I don't have the pre-build step, then I get this warning Skipping build. Using service image ${service_image} from Docker Compose config. I want it to build the image anyway because otherwise my latest code does not get built into the image.