The repositories
file at the top level of a Docker image archive
contains a list of images contained in the image and layer id of the
"topmost" layer:
{
"fedora": {
"21": "834629358fe214f210b0ed606fba2c17827d7a46dd74bd3309afc2a103ad0e89",
"20": "6cece30db4f924da43969a12fdf47492ada22b372a0968d6ca8b71d25876629f"
}
}
Each layer contained in the archive contains a file named json
with
the following format:
{
"Size": 0,
"os": "linux",
"architecture": "amd64",
"id": "4986bf8c15363d1c5d15512d5266f8777bfba4974ac56e3270e7760f6f0a8125",
"parent": "ea13149945cb6b1e746bf28032f02e9b5a793523481a0a18645fc77ad53c4ea2",
"created": "2014-12-31T22:23:56.943403668Z",
"container": "83dcf36ad1042b90f4ea8b2ebb60e61b2f1a451a883e04b388be299ad382b259",
"container_config": {
"OnBuild": [],
"MacAddress": "",
"NetworkDisabled": false,
"Entrypoint": null,
"WorkingDir": "",
"Volumes": null,
"Image": "ea13149945cb6b1e746bf28032f02e9b5a793523481a0a18645fc77ad53c4ea2",
"Cmd": [
"/bin/sh",
"-c",
"#(nop) CMD [/bin/sh]"
],
"AttachStdin": false,
"Cpuset": "",
"CpuShares": 0,
"MemorySwap": 0,
"Memory": 0,
"User": "",
"Domainname": "",
"Hostname": "7f674915980d",
"AttachStdout": false,
"AttachStderr": false,
"PortSpecs": null,
"ExposedPorts": null,
"Tty": false,
"OpenStdin": false,
"StdinOnce": false,
"Env": [
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
]
},
"docker_version": "1.4.1",
"author": "Jérôme Petazzoni <jerome@docker.com>",
"config": {
"OnBuild": [],
"MacAddress": "",
"NetworkDisabled": false,
"Entrypoint": null,
"WorkingDir": "",
"Volumes": null,
"Image": "ea13149945cb6b1e746bf28032f02e9b5a793523481a0a18645fc77ad53c4ea2",
"Cmd": [
"/bin/sh"
],
"AttachStdin": false,
"Cpuset": "",
"CpuShares": 0,
"MemorySwap": 0,
"Memory": 0,
"User": "",
"Domainname": "",
"Hostname": "7f674915980d",
"AttachStdout": false,
"AttachStderr": false,
"PortSpecs": null,
"ExposedPorts": null,
"Tty": false,
"OpenStdin": false,
"StdinOnce": false,
"Env": [
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
]
}
}