build: use distroless/static instead of gcr.io/distroless/cc

[odeke-em]

Summary of Bug

The Dockerfile uses the base image

gaia/Dockerfile

Line 14 in 91097a3

FROM gcr.io/distroless/cc:$IMG_TAG

gcr.io/distroless/cc is a big image, not well maintained, dates of updated not even maintained but even more it isn't signed so at the mercy of whoever uploads it. For a quick comparison, please see this comparison

$ docker images | grep distro
distroless.dev/static                    latest      47fb349c19cc   23 hours ago    1.44MB
gcr.io/distroless/cc                     latest      af03863dbb6a   52 years ago    22.6MB

The current image is 22.6MB, claims it was last uploaded 52 years ago

whereas distroless.dev/static is 1.44MB, uploaded nightly, signed, auditable and well maintained.

Recommendation

Use distroless.dev/static and incorporate #1620 too to build static binaries linked against musl

Kindly ccing my colleagues at Orijtech @kirbyquerby @elias-orijtech @willpoint

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