From 94d92c7796a3dd50c27d532315f7d497ac99f08e Mon Sep 17 00:00:00 2001 From: Ludovic Courtès Date: Mon, 20 Jul 2015 04:30:16 +0200 Subject: daemon: Add "builtin:download" derivation builder. This ensures that 1) the derivation doesn't change when Guix changes; 2) the derivation closure doesn't contain Guix and its dependencies; 3) we don't have to rely on ugly chroot hacks. Adapted from Nix commit 0a2bee307b20411f5b0dda0c662b1f9bb9e0e131. * nix/libstore/build.cc (DerivationGoal::runChild): Add special case for 'isBuiltin(drv)'. Disable chroot when 'isBuiltin(drv)'. * nix/libstore/builtins.cc, nix/libstore/builtins.hh, nix/scripts/download.in, guix/scripts/perform-download.scm: New files. * guix/ui.scm (show-guix-help)[internal?]: Add 'perform-download'. * nix/local.mk (libstore_a_SOURCES): Add builtins.cc. (libstore_headers): Add builtins.hh. (nodist_pkglibexec_SCRIPTS): Add 'scripts/download'. * config-daemon.ac: Emit 'scripts/download'. * Makefile.am (MODULES): Add 'guix/scripts/perform-download.scm'. * tests/derivations.scm ("unknown built-in builder") ("'download' built-in builder") ("'download' built-in builder, invalid hash") ("'download' built-in builder, not found") ("'download' built-in builder, not fixed-output"): New tests. Co-authored-by: Eelco Dolstra --- nix/libstore/build.cc | 36 ++++++++++++++++++++----- nix/libstore/builtins.cc | 69 ++++++++++++++++++++++++++++++++++++++++++++++++ nix/libstore/builtins.hh | 41 ++++++++++++++++++++++++++++ 3 files changed, 139 insertions(+), 7 deletions(-) create mode 100644 nix/libstore/builtins.cc create mode 100644 nix/libstore/builtins.hh (limited to 'nix/libstore') diff --git a/nix/libstore/build.cc b/nix/libstore/build.cc index ae78e65199..889ee3d2bd 100644 --- a/nix/libstore/build.cc +++ b/nix/libstore/build.cc @@ -8,6 +8,7 @@ #include "util.hh" #include "archive.hh" #include "affinity.hh" +#include "builtins.hh" #include #include @@ -2047,7 +2048,12 @@ void DerivationGoal::runChild() commonChildInit(builderOut); #if CHROOT_ENABLED - if (useChroot) { + /* Note: built-in builders are *not* running in a chroot environment + so that we can easily implement them in Guile without having it as + a derivation input (they are running under a separate build user, + though). */ + + if (useChroot && !isBuiltin(drv)) { /* Initialise the loopback interface. */ AutoCloseFD fd(socket(PF_INET, SOCK_DGRAM, IPPROTO_IP)); if (fd == -1) throw SysError("cannot open IP socket"); @@ -2255,6 +2261,28 @@ void DerivationGoal::runChild() throw SysError("setuid failed"); } + restoreSIGPIPE(); + + /* Indicate that we managed to set up the build environment. */ + writeFull(STDERR_FILENO, "\n"); + + /* Execute the program. This should not return. */ + if (isBuiltin(drv)) { + try { + logType = ltFlat; + + auto buildDrv = lookupBuiltinBuilder(drv.builder); + if (buildDrv != NULL) + buildDrv(drv, drvPath); + else + throw Error(format("unsupported builtin function '%1%'") % string(drv.builder, 8)); + _exit(0); + } catch (std::exception & e) { + writeFull(STDERR_FILENO, "error: " + string(e.what()) + "\n"); + _exit(1); + } + } + /* Fill in the arguments. */ Strings args; string builderBasename = baseNameOf(drv.builder); @@ -2262,12 +2290,6 @@ void DerivationGoal::runChild() foreach (Strings::iterator, i, drv.args) args.push_back(rewriteHashes(*i, rewritesToTmp)); - restoreSIGPIPE(); - - /* Indicate that we managed to set up the build environment. */ - writeFull(STDERR_FILENO, "\n"); - - /* Execute the program. This should not return. */ execve(drv.builder.c_str(), stringsToCharPtrs(args).data(), stringsToCharPtrs(envStrs).data()); throw SysError(format("executing `%1%'") % drv.builder); diff --git a/nix/libstore/builtins.cc b/nix/libstore/builtins.cc new file mode 100644 index 0000000000..605e44079a --- /dev/null +++ b/nix/libstore/builtins.cc @@ -0,0 +1,69 @@ +/* GNU Guix --- Functional package management for GNU + Copyright (C) 2016 Ludovic Courtès + + This file is part of GNU Guix. + + GNU Guix is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or (at + your option) any later version. + + GNU Guix is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with GNU Guix. If not, see . */ + +#include +#include +#include + +#include + +namespace nix { + +static void builtinDownload(const Derivation &drv, + const std::string &drvPath) +{ + /* Invoke 'guix perform-download'. */ + Strings args; + args.push_back("perform-download"); + args.push_back(drvPath); + + /* Close all other file descriptors. */ + closeMostFDs(set()); + + const char *const argv[] = { "download", drvPath.c_str(), NULL }; + + /* XXX: Hack our way to use the 'download' script from 'LIBEXECDIR/guix' + or just 'LIBEXECDIR', depending on whether we're running uninstalled or + not. */ + const string subdir = getenv("GUIX_UNINSTALLED") != NULL + ? "" : "/guix"; + + const string program = settings.nixLibexecDir + subdir + "/download"; + execv(program.c_str(), (char *const *) argv); + + throw SysError(format("failed to run download program '%1%'") % program); +} + +static const std::map builtins = +{ + { "download", builtinDownload } +}; + +derivationBuilder lookupBuiltinBuilder(const std::string & name) +{ + if (name.substr(0, 8) == "builtin:") + { + auto realName = name.substr(8); + auto builder = builtins.find(realName); + return builder == builtins.end() ? NULL : builder->second; + } + else + return NULL; +} + +} diff --git a/nix/libstore/builtins.hh b/nix/libstore/builtins.hh new file mode 100644 index 0000000000..0c6db651ab --- /dev/null +++ b/nix/libstore/builtins.hh @@ -0,0 +1,41 @@ +/* GNU Guix --- Functional package management for GNU + Copyright (C) 2016 Ludovic Courtès + + This file is part of GNU Guix. + + GNU Guix is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or (at + your option) any later version. + + GNU Guix is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with GNU Guix. If not, see . */ + +/* Interface to built-in derivation builders. */ + +#pragma once + +#include +#include +#include + +namespace nix { + + inline bool isBuiltin(const Derivation & drv) + { + return string(drv.builder, 0, 8) == "builtin:"; + } + + /* Build DRV, which lives at DRVPATH. */ + typedef void (*derivationBuilder) (const Derivation &drv, + const std::string &drvPath); + + /* Return the built-in builder called BUILDER, or NULL if none was + found. */ + derivationBuilder lookupBuiltinBuilder(const std::string &builder); +} -- cgit v1.2.3