Familiar with Docker, and looking for more specific information about when
images get pulled or updated in Tugboat? Here’s what you need to know about
docker pull under the hood:
Tugboat doesn’t pull the images in your config file every time you open a pull
request, or refresh a Preview; it only does a
docker pull (under the hood)
Otherwise, Tugboat relies on the images you pulled when the Preview was first created; Preview Actions like Refreshing a Preview, Cloning a Preview, or automatically generating a Preview from a pull request when you’re using a Base Preview - those things all keep the Docker images you referenced when you first built the Preview.
Because Tugboat pulls your Docker images at the beginning of the Preview build
process, it won’t
docker pull an updated image unless you kick off the Preview
build process from scratch again.
For more info, see: Why Build phases matter.
If your Tugboat Preview isn’t pulling your latest Docker
image tag, it might be because you’re building from a Base Preview. If that’s
the case, you’ll need to
Rebuild your Base Preview,
which executes an API call to
docker pull under the hood to grab the image tag
referenced in your
config file. If that still
doesn’t get you the image you expect, check your config file to see which
image tag you’re pulling; you may need to change the
reference to latest, or a specific image tag, to get the result you want.