nixpkgs/pkgs/build-support/docker/pull.sh
Arthur Noel 903129f770 dockerTools: private registry support
* authorization token is optional
* registry url is taken from X-Docker-Endpoints header
* pull.sh correctly resumes partial layer downloads
* detjson.py does not fail on missing keys
2016-01-27 21:13:07 +00:00

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# Reference: docker src contrib/download-frozen-image.sh
source $stdenv/setup
# Curl flags to handle redirects, not use EPSV, handle cookies for
# servers to need them during redirects, and work on SSL without a
# certificate (this isn't a security problem because we check the
# cryptographic hash of the output anyway).
curl=$(command -v curl)
curl() {
[[ -n ${token:-} ]] && set -- -H "Authorization: Token $token" "$@"
$curl \
--location --max-redirs 20 \
--retry 3 \
--fail \
--disable-epsv \
--cookie-jar cookies \
--insecure \
$curlOpts \
$NIX_CURL_FLAGS \
"$@"
}
fetchLayer() {
local url="$1"
local dest="$2"
local curlexit=18;
# if we get error code 18, resume partial download
while [ $curlexit -eq 18 ]; do
# keep this inside an if statement, since on failure it doesn't abort the script
if curl -C - "$url" --output "$dest"; then
return 0
else
curlexit=$?;
fi
done
return $curlexit
}
headers=$(curl -o /dev/null -D- -H 'X-Docker-Token: true' \
"$indexUrl/$registryVersion/repositories/$imageName/images")
header() {
grep $1 <<< "$headers" | tr -d '\r' | cut -d ' ' -f 2
}
# this only takes the first endpoint, more may be provided
# https://docs.docker.com/v1.6/reference/api/docker-io_api/
if ! registryUrl=$(header X-Docker-Endpoints); then
echo "error: index returned no endpoint"
exit 1
fi
baseUrl="https://$registryUrl/$registryVersion"
token="$(header X-Docker-Token || true)";
if [ -z "$imageId" ]; then
imageId="$(curl "$baseUrl/repositories/$imageName/tags/$imageTag")"
imageId="${imageId//\"/}"
if [ -z "$imageId" ]; then
echo "error: no image ID found for ${imageName}:${imageTag}"
exit 1
fi
echo "found image ${imageName}:${imageTag}@$imageId"
fi
mkdir -p $out
jshon -n object \
-n object -s "$imageId" -i "$imageTag" \
-i "$imageName" > $out/repositories
curl "$baseUrl/images/$imageId/ancestry" -o ancestry.json
layerIds=$(jshon -a -u < ancestry.json)
for layerId in $layerIds; do
echo "fetching layer $layerId"
mkdir "$out/$layerId"
echo '1.0' > "$out/$layerId/VERSION"
curl "$baseUrl/images/$layerId/json" | python $detjson > "$out/$layerId/json"
fetchLayer "$baseUrl/images/$layerId/layer" "$out/$layerId/layer.tar"
done