github.com/duglin/docker@v1.13.1/hack/make/.ensure-emptyfs (about)

     1  #!/bin/bash
     2  set -e
     3  
     4  if ! docker inspect emptyfs &> /dev/null; then
     5  	# let's build a "docker save" tarball for "emptyfs"
     6  	# see https://github.com/docker/docker/pull/5262
     7  	# and also https://github.com/docker/docker/issues/4242
     8  	dir="$DEST/emptyfs"
     9  	mkdir -p "$dir"
    10  	(
    11  		cd "$dir"
    12  		echo '{"emptyfs":{"latest":"511136ea3c5a64f264b78b5433614aec563103b4d4702f3ba7d4d2698e22c158"}}' > repositories
    13  		mkdir -p 511136ea3c5a64f264b78b5433614aec563103b4d4702f3ba7d4d2698e22c158
    14  		(
    15  			cd 511136ea3c5a64f264b78b5433614aec563103b4d4702f3ba7d4d2698e22c158
    16  			echo '{"id":"511136ea3c5a64f264b78b5433614aec563103b4d4702f3ba7d4d2698e22c158","comment":"Imported from -","created":"2013-06-13T14:03:50.821769-07:00","container_config":{"Hostname":"","Domainname":"","User":"","Memory":0,"MemorySwap":0,"CpuShares":0,"AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"PortSpecs":null,"ExposedPorts":null,"Tty":false,"OpenStdin":false,"StdinOnce":false,"Env":null,"Cmd":null,"Image":"","Volumes":null,"WorkingDir":"","Entrypoint":null,"NetworkDisabled":false,"OnBuild":null},"docker_version":"0.4.0","architecture":"x86_64","Size":0}' > json
    17  			echo '1.0' > VERSION
    18  			tar -cf layer.tar --files-from /dev/null
    19  		)
    20  	)
    21  	( set -x; tar -cC "$dir" . | docker load )
    22  	rm -rf "$dir"
    23  fi