nixpkgs/pkgs/build-support/fetchurl/builder.sh
Eelco Dolstra a7c209e474 * Interface to support mirror:// in nix-prefetch-url. The function
resolveMirrorURLs produces a file containing the URLs to which a
  mirror:// URL resolves.

svn path=/nixpkgs/trunk/; revision=12410
2008-07-23 16:04:10 +00:00

127 lines
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source $stdenv/setup
if test -n "$showURLs"; then
header "downloading file $name with $outputHashAlgo hash $outputHash..."
fi
# 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="curl \
--location --max-redirs 20 \
--disable-epsv \
--cookie-jar cookies \
--insecure"
tryDownload() {
local url="$1"
echo
header "trying $url"
success=
if $curl --fail "$url" --output "$out"; then
success=1
fi
stopNest
}
finish() {
# On old versions of Nix, verify the hash of the output. On newer
# versions, Nix verifies the hash itself.
if test "$NIX_OUTPUT_CHECKED" != "1"; then
if test "$outputHashAlgo" != "md5"; then
echo "hashes other than md5 are unsupported in Nix <= 0.7, upgrade to Nix 0.8"
exit 1
fi
actual=$(md5sum -b "$out" | cut -c1-32)
if test "$actual" != "$id"; then
echo "hash is $actual, expected $id"
exit 1
fi
fi
stopNest
exit 0
}
tryHashedMirrors() {
if test -n "$NIX_HASHED_MIRRORS"; then
hashedMirrors="$NIX_HASHED_MIRRORS"
fi
for mirror in $hashedMirrors; do
url="$mirror/$outputHashAlgo/$outputHash"
if $curl --fail --silent --show-error --head "$url" \
--write-out "%{http_code}" --output /dev/null > code 2> log; then
tryDownload "$url"
if test -n "$success"; then finish; fi
else
# Be quiet about 404 errors, which we interpret as the file
# not being present on this particular mirror.
if test "$(cat code)" != 404; then
echo "error checking the existence of $url:"
cat log
fi
fi
done
}
urls2=
for url in $urls; do
if test "${url:0:9}" != "mirror://"; then
urls2="$urls2 $url"
else
url2="${url:9}"; echo "${url2/\// }" > split; read site fileName < split
#varName="mirror_$site"
varName="$site" # !!! danger of name clash, fix this
if test -z "${!varName}"; then
echo "warning: unknown mirror:// site \`$site'"
else
# Assume that SourceForge/GNU/kernel mirrors have better
# bandwidth than nix.cs.uu.nl.
preferHashedMirrors=
mirrors=${!varName}
# Allow command-line override by setting NIX_MIRRORS_$site.
varName="NIX_MIRRORS_$site"
if test -n "${!varName}"; then mirrors="${!varName}"; fi
for url3 in $mirrors; do
urls2="$urls2 $url3$fileName";
done
fi
fi
done
urls="$urls2"
if test -n "$showURLs"; then
echo "$urls" > $out
exit 0
fi
if test -n "$preferHashedMirrors"; then
tryHashedMirrors
fi
success=
for url in $urls; do
tryDownload "$url"
if test -n "$success"; then finish; fi
done
if test -z "$preferHashedMirrors"; then
tryHashedMirrors
fi
echo "error: cannot download $name from any mirror"
exit 1