lunaphied/lix
0
0
Fork 0
forked from lix-project/lix
Code Pull requests Activity

Add hashed-mirrors back

Browse source 
Some users have their own hashed-mirrors setup, that is used to mirror
things in addition to what’s available on tarballs.nixos.org. Although
this should be feasable to do with a Binary Cache, it’s not always
easy, since you have to remember what "name" each of the tarballs has.
Continuing to support hashed-mirrors is cheap, so it’s best to leave
support in Nix. Note that NIX_HASHED_MIRRORS is also supported in
Nixpkgs through fetchurl.nix.

Note that this excludes tarballs.nixos.org from the default, as in
\#3689. All of these are available on cache.nixos.org.
This commit is contained in:
Matthew Bauer 2020-08-06 18:13:14 -05:00
parent 24e07c428f
commit 641c950701
3 changed files with 44 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

27
doc/manual/command-ref/conf-file.xml
View file

@ -370,6 +370,33 @@ false</literal>.</para>
</varlistentry>
<varlistentry xml:id="conf-hashed-mirrors"><term><literal>hashed-mirrors</literal></term>
<listitem><para>A list of web servers used by
<function>builtins.fetchurl</function> to obtain files by hash.
Given a hash type <replaceable>ht</replaceable> and a base-16 hash
<replaceable>h</replaceable>, Nix will try to download the file
from
<literal>hashed-mirror/<replaceable>ht</replaceable>/<replaceable>h</replaceable></literal>.
This allows files to be downloaded even if they have disappeared
from their original URI. For example, given the hashed mirror
<literal>http://tarballs.example.com/</literal>, when building the
derivation
<programlisting>
builtins.fetchurl {
url = "https://example.org/foo-1.2.3.tar.xz";
sha256 = "2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae";
}
</programlisting>
Nix will attempt to download this file from
<literal>http://tarballs.example.com/sha256/2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae</literal>
first. If it is not available there, if will try the original URI.</para></listitem>
</varlistentry>
<varlistentry xml:id="conf-http-connections"><term><literal>http-connections</literal></term>
<listitem><para>The maximum number of parallel TCP connections

14
src/libstore/builtins/fetchurl.cc
View file

@ -58,6 +58,20 @@ void builtinFetchurl(const BasicDerivation & drv, const std::string & netrcData)
}
};
/* Try the hashed mirrors first. */
if (getAttr("outputHashMode") == "flat")
for (auto hashedMirror : settings.hashedMirrors.get())
try {
if (!hasSuffix(hashedMirror, "/")) hashedMirror += '/';
auto ht = parseHashType(getAttr("outputHashAlgo"));
auto h = Hash(getAttr("outputHash"), ht);
fetch(hashedMirror + printHashType(h.type) + "/" + h.to_string(Base16, false));
return;
} catch (Error & e) {
debug(e.what());
}
/* Otherwise try the specified URL. */
fetch(mainUrl);
}

3
src/libstore/globals.hh
View file

@ -335,6 +335,9 @@ public:
"setuid/setgid bits or with file capabilities."};
#endif
Setting<Strings> hashedMirrors{this, {}, "hashed-mirrors",
"A list of servers used by builtins.fetchurl to fetch files by hash."};
Setting<uint64_t> minFree{this, 0, "min-free",
"Automatically run the garbage collector when free disk space drops below the specified amount."};