* Load container images descending by size
Loading container images using docker load seems to require more space
at load time (which gets freed after loading). Loading the largest
container first avoids running out of space.
It seems that the GitHub container registry sometimes returns 503
service unavailable temporarily ("Error fetching tags list: invalid status
code from registry 503"). Use skopeo's retry mechanism to try up to 5
times before failing.
* Avoid race condition when fetching containers during build
So far only a single builder was active for each architecture. This
toghether with the naming scheme to include architecture/machine name
made sure that an image could only be fetched or used by a single
builder.
However, since most systems are now aarch64, multiple runners are now
active for a single architecture. This makes it necessary to lock
fetching/coping of container images to avoid race conditions.
Sometimes the first command after starting the Docker daemon container
fails, presumably because the container did not start yet. Wait until
the Docker daemon is ready.
* Use skopeo to download container images
Separate container download from image build. This will allow to share
the downloaded images between multiple builds.
We won't store the Supervisor container with the version tag, just with
the latest tag. This allows to simplify the procedure a bit. It seems
there is no downside to this approach.
* Use official Docker in Docker images to build data partition
Instead of building our own Debian based image let's use the official
Docker in Docker image. This avoids building an image for the hassio
data partition and speeds up build as well.
This calls mount commands using sudo to mount the data partition as part
of the buildroot build now. This is not much different from before as
mount has been called as root inside the container, essentially equates
to the same "isolation" level.
* Use image digest as part of the file name
The landing page has no version information in the tag. To avoid
potentially source caching issues, use the digest as part of the file
name.
The landingpage container is a minimal webserver with built-in zeroconf
annoucement. Preinstall the machine specific landingpage container to
make sure it will show up right after startup.
