The build stage ran on the target platform, so a multi-platform build
ran the Go toolchain under qemu. On hosts with an older qemu-user
(Ubuntu 22.04 ships 6.2) Go crashed building linux/arm/v7, and the
image still built: scripts/build.sh did not fail on a build error, and
the COPY of ctrld-linux-*-nocgo matched nothing, so the image shipped
without ctrld.
In both docker/Dockerfile and docker/Dockerfile.debug, run the build
stage on BUILDPLATFORM and cross-compile for the target with
scripts/build.sh linux/amd64, linux/arm64 or linux/armv7. Then move
the binary built for that target, by its exact name, to a fixed path,
and fail when it is missing. scripts/build.sh now exits non-zero when
go generate or go build fails, and .dockerignore keeps ctrld-* files
from the host out of the build context, so a leftover binary can never
stand in for a failed build. Drop the outdated CTRLD_NO_QF variable.
Using the same approach as in cd mode, but do it only once when running
ctrld the first time, then the config will be re-used then.
While at it, also adding Dockerfile.debug for better troubleshooting
with alpine base image.
Cuong Manh Le