pyrox.dev
1# Reference: docker src contrib/download-frozen-image.sh
2
3source $stdenv/setup
4
5# Curl flags to handle redirects, not use EPSV, handle cookies for
6# servers to need them during redirects, and work on SSL without a
7# certificate (this isn't a security problem because we check the
8# cryptographic hash of the output anyway).
9curl=$(command -v curl)
10curl() {
11 [[ -n ${token:-} ]] && set -- -H "Authorization: Token $token" "$@"
12 $curl \
13 --location --max-redirs 20 \
14 --retry 3 \
15 --fail \
16 --disable-epsv \
17 --cookie-jar cookies \
18 --insecure \
19 $curlOpts \
20 $NIX_CURL_FLAGS \
21 "$@"
22}
23
24fetchLayer() {
25 local url="$1"
26 local dest="$2"
27 local curlexit=18;
28
29 # if we get error code 18, resume partial download
30 while [ $curlexit -eq 18 ]; do
31 # keep this inside an if statement, since on failure it doesn't abort the script
32 if curl -C - "$url" --output "$dest"; then
33 return 0
34 else
35 curlexit=$?;
36 fi
37 done
38
39 return $curlexit
40}
41
42headers=$(curl -o /dev/null -D- -H 'X-Docker-Token: true' \
43 "$indexUrl/$registryVersion/repositories/$imageName/images")
44
45header() {
46 grep $1 <<< "$headers" | tr -d '\r' | cut -d ' ' -f 2
47}
48
49# this only takes the first endpoint, more may be provided
50# https://docs.docker.com/v1.6/reference/api/docker-io_api/
51if ! registryUrl=$(header X-Docker-Endpoints); then
52 echo "error: index returned no endpoint"
53 exit 1
54fi
55baseUrl="https://$registryUrl/$registryVersion"
56
57token="$(header X-Docker-Token || true)";
58
59if [ -z "$imageId" ]; then
60 imageId="$(curl "$baseUrl/repositories/$imageName/tags/$imageTag")"
61 imageId="${imageId//\"/}"
62 if [ -z "$imageId" ]; then
63 echo "error: no image ID found for ${imageName}:${imageTag}"
64 exit 1
65 fi
66
67 echo "found image ${imageName}:${imageTag}@$imageId"
68fi
69
70mkdir -p $out
71
72jshon -n object \
73 -n object -s "$imageId" -i "$imageTag" \
74 -i "$imageName" > $out/repositories
75
76curl "$baseUrl/images/$imageId/ancestry" -o ancestry.json
77
78layerIds=$(jshon -a -u < ancestry.json)
79for layerId in $layerIds; do
80 echo "fetching layer $layerId"
81
82 mkdir "$out/$layerId"
83 echo '1.0' > "$out/$layerId/VERSION"
84 curl "$baseUrl/images/$layerId/json" | python $detjson > "$out/$layerId/json"
85 fetchLayer "$baseUrl/images/$layerId/layer" "$out/$layerId/layer.tar"
86done