Nix/src/libstore/builtins/fetchurl.cc

85 lines
2.8 KiB
C++

#include "builtins.hh"
#include "filetransfer.hh"
#include "store-api.hh"
#include "archive.hh"
#include "compression.hh"
namespace nix {
void builtinFetchurl(const BasicDerivation & drv, const std::string & netrcData)
{
/* Make the host's netrc data available. Too bad curl requires
this to be stored in a file. It would be nice if we could just
pass a pointer to the data. */
if (netrcData != "") {
settings.netrcFile = "netrc";
writeFile(settings.netrcFile, netrcData, 0600);
}
auto out = get(drv.outputs, "out");
if (!out)
throw Error("'builtin:fetchurl' requires an 'out' output");
auto dof = std::get_if<DerivationOutput::CAFixed>(&out->raw);
if (!dof)
throw Error("'builtin:fetchurl' must be a fixed-output derivation");
auto getAttr = [&](const std::string & name) {
auto i = drv.env.find(name);
if (i == drv.env.end()) throw Error("attribute '%s' missing", name);
return i->second;
};
Path storePath = getAttr("out");
auto mainUrl = getAttr("url");
bool unpack = getOr(drv.env, "unpack", "") == "1";
/* Note: have to use a fresh fileTransfer here because we're in
a forked process. */
auto fileTransfer = makeFileTransfer();
auto fetch = [&](const std::string & url) {
auto source = sinkToSource([&](Sink & sink) {
/* No need to do TLS verification, because we check the hash of
the result anyway. */
FileTransferRequest request(url);
request.verifyTLS = false;
request.decompress = false;
auto decompressor = makeDecompressionSink(
unpack && hasSuffix(mainUrl, ".xz") ? "xz" : "none", sink);
fileTransfer->download(std::move(request), *decompressor);
decompressor->finish();
});
if (unpack)
restorePath(storePath, *source);
else
writeFile(storePath, *source);
auto executable = drv.env.find("executable");
if (executable != drv.env.end() && executable->second == "1") {
if (chmod(storePath.c_str(), 0755) == -1)
throw SysError("making '%1%' executable", storePath);
}
};
/* Try the hashed mirrors first. */
if (dof->ca.method.getFileIngestionMethod() == FileIngestionMethod::Flat)
for (auto hashedMirror : settings.hashedMirrors.get())
try {
if (!hasSuffix(hashedMirror, "/")) hashedMirror += '/';
fetch(hashedMirror + printHashAlgo(dof->ca.hash.algo) + "/" + dof->ca.hash.to_string(HashFormat::Base16, false));
return;
} catch (Error & e) {
debug(e.what());
}
/* Otherwise try the specified URL. */
fetch(mainUrl);
}
}