Nerd snipe
An image with only: /bin/ed, /lib/musl.so, and /tmp.
Comes out to 640kB, which should be enough for anybody.
FROM alpine AS builder
RUN apk add ed
FROM scratch
COPY --from=builder /tmp /tmp
COPY --from=builder /lib/ld-musl-x86_64.so.1 /lib/
COPY --from=builder /bin/ed /bin/
ENTRYPOINT ["/bin/ed"]