installed: redis@sha256:858f009f9709ce576febc734aa78b8f6d624b82571f9ddb6bda4377c833b3499
ref with tag AND digest: redis:7-alpine@sha256:858f009f9709ce576febc734aa78b8f6d624b82571f9ddb6bda4377c833b3499
docker.io/library/redis:7-alpine@sha256:858f009f9709ce576febc734aa78b8f6d624b82571f9ddb6bda4377c833b3499
pull rc=0
    image: redis:7-alpine@sha256:858f009f9709ce576febc734aa78b8f6d624b82571f9ddb6bda4377c833b3499
Redis server v=7.4.11 sha=00000000:0 malloc=jemalloc-5.3.0 bits=64 build=40ff01a501d8e4b6
negative control — a digest that does not exist:
Error response from daemon: manifest for redis@sha256:0000000000000000000000000000000000000000000000000000000000000000 not found: manifest unknown: manifest unknown
rc=0
NOTE (added after the run): the 'rc=0' on the last line is the exit code of the 'tail' in that pipe, NOT of docker pull — the refusal is the daemon's own sentence above it.
