Recorded run image build issues

[craig-willis]

From v1.2rc1 testing

Problem
A recorded run builds an image if not already present for a version. Currently, RR doesn't update the image digest associated with a version, so it is possible to have the wrong image associated with a run/version. We don't require users to build the image before publishing/exporting a version anyway, so now that we include the digest there's a chance that it is wrong. Also, it appears that RR build fails if the image hasn't been previously built.

Test

• Create a new tale and add apt.txt and run.sh but do not build or restart the tale
• Start a recorded run
• On success, export or publish the version with the run
• Expected: digest in imageInfo is digest from recorded run (i.e., incorporating apt.txt)
• Actual: digest is of original pre-RR image

[craig-willis]

A few thoughts on this:

• For v1.1, we don't include the image/digest on publish or export. Anyone who tries to use a published/exported tale needs to rebuild the image either locally or by importing into WT.
• Building an image for a version is currently optional. We shouldn't include the digest on export/publish if the version was never built.
• As suggested by @Xarthisius, we can generate the digest (via dryrun) for a version without building. This is problematic if the version contains errors that would cause the build to fail.
• A recorded run builds the image for a version. The recorded run could update the digest for the version, but this means modifying the version metadata.