+ docker pull alpine:3.9 3.9: Pulling from library/alpine 9123ac7c32f7: Pulling fs layer 9123ac7c32f7: Download complete 9123ac7c32f7: Pull complete Digest: sha256:115731bab0862031b44766733890091c17924f9b7781b79997f5f163be262178 Status: Downloaded newer image for alpine:3.9