github.com/daaku/docker@v1.5.0/project/make/.ensure-scratch (about)

     1  #!/bin/bash
     2  
     3  if ! docker inspect scratch &> /dev/null; then
     4  	# let's build a "docker save" tarball for "emptyfs"
     5  	# see https://github.com/docker/docker/pull/5262
     6  	# and also https://github.com/docker/docker/issues/4242
     7  	mkdir -p /docker-scratch
     8  	(
     9  		cd /docker-scratch
    10  		echo '{"emptyfs":{"latest":"511136ea3c5a64f264b78b5433614aec563103b4d4702f3ba7d4d2698e22c158"}}' > repositories
    11  		mkdir -p 511136ea3c5a64f264b78b5433614aec563103b4d4702f3ba7d4d2698e22c158
    12  		(
    13  			cd 511136ea3c5a64f264b78b5433614aec563103b4d4702f3ba7d4d2698e22c158
    14  			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
    15  			echo '1.0' > VERSION
    16  			tar -cf layer.tar --files-from /dev/null
    17  		)
    18  	)
    19  	( set -x; tar -cf /docker-scratch.tar -C /docker-scratch . )
    20  	( set -x; docker load --input /docker-scratch.tar )
    21  fi