#include <algorithm> #include <cstdlib> #include <cstring> #include <iomanip> #include <memory> #include <set> #include <tuple> #include <absl/strings/ascii.h> #include <absl/strings/match.h> #include <absl/strings/str_cat.h> #include <glog/logging.h> #include "libmain/shared.hh" #include "libstore/derivations.hh" #include "libstore/globals.hh" #include "libstore/local-store.hh" #include "libstore/machines.hh" #include "libstore/pathlocks.hh" #include "libstore/store-api.hh" #include "libutil/serialise.hh" #include "nix/legacy.hh" using namespace nix; using std::cin; static void handleAlarm(int sig) {} std::string escapeUri(std::string uri) { std::replace(uri.begin(), uri.end(), '/', '_'); return uri; } static std::string currentLoad; static AutoCloseFD openSlotLock(const Machine& m, unsigned long long slot) { return openLockFile(fmt("%s/%s-%d", currentLoad, escapeUri(m.storeUri), slot), true); } static bool allSupportedLocally(const std::set<std::string>& requiredFeatures) { for (auto& feature : requiredFeatures) { if (settings.systemFeatures.get().count(feature) == 0u) { return false; } } return true; } static int _main(int argc, char* argv[]) { { /* Ensure we don't get any SSH passphrase or host key popups. */ unsetenv("DISPLAY"); unsetenv("SSH_ASKPASS"); if (argc != 2) { throw UsageError("called without required arguments"); } FdSource source(STDIN_FILENO); /* Read the parent's settings. */ while (readInt(source) != 0u) { auto name = readString(source); auto value = readString(source); settings.set(name, value); } settings.maxBuildJobs.set("1"); // hack to make tests with local?root= work auto store = openStore().cast<LocalStore>(); /* It would be more appropriate to use $XDG_RUNTIME_DIR, since that gets cleared on reboot, but it wouldn't work on macOS. */ currentLoad = store->stateDir + "/current-load"; std::shared_ptr<Store> sshStore; AutoCloseFD bestSlotLock; auto machines = getMachines(); DLOG(INFO) << "got " << machines.size() << " remote builders"; if (machines.empty()) { std::cerr << "# decline-permanently\n"; return 0; } std::string drvPath; std::string storeUri; while (true) { try { auto s = readString(source); if (s != "try") { return 0; } } catch (EndOfFile&) { return 0; } auto amWilling = readInt(source); auto neededSystem = readString(source); source >> drvPath; auto requiredFeatures = readStrings<std::set<std::string>>(source); auto canBuildLocally = (amWilling != 0u) && (neededSystem == settings.thisSystem || settings.extraPlatforms.get().count(neededSystem) > 0) && allSupportedLocally(requiredFeatures); /* Error ignored here, will be caught later */ mkdir(currentLoad.c_str(), 0777); while (true) { bestSlotLock = -1; AutoCloseFD lock = openLockFile(currentLoad + "/main-lock", true); lockFile(lock.get(), ltWrite, true); bool rightType = false; Machine* bestMachine = nullptr; unsigned long long bestLoad = 0; for (auto& m : machines) { DLOG(INFO) << "considering building on remote machine '" << m.storeUri << "'"; if (m.enabled && std::find(m.systemTypes.begin(), m.systemTypes.end(), neededSystem) != m.systemTypes.end() && m.allSupported(requiredFeatures) && m.mandatoryMet(requiredFeatures)) { rightType = true; AutoCloseFD free; unsigned long long load = 0; for (unsigned long long slot = 0; slot < m.maxJobs; ++slot) { auto slotLock = openSlotLock(m, slot); if (lockFile(slotLock.get(), ltWrite, false)) { if (!free) { free = std::move(slotLock); } } else { ++load; } } if (!free) { continue; } bool best = false; if (!bestMachine || !bestSlotLock) { best = true; } else if (load / m.speedFactor < bestLoad / bestMachine->speedFactor) { best = true; } else if (load / m.speedFactor == bestLoad / bestMachine->speedFactor) { if (m.speedFactor > bestMachine->speedFactor) { best = true; } else if (m.speedFactor == bestMachine->speedFactor) { if (load < bestLoad) { best = true; } } } if (best) { bestLoad = load; bestSlotLock = std::move(free); bestMachine = &m; } } } if (!bestSlotLock || !bestMachine) { if (rightType && !canBuildLocally) { std::cerr << "# postpone\n"; } else { std::cerr << "# decline\n"; } break; } futimens(bestSlotLock.get(), nullptr); lock = -1; try { DLOG(INFO) << "connecting to '" << bestMachine->storeUri << "'"; Store::Params storeParams; if (absl::StartsWith(bestMachine->storeUri, "ssh://")) { storeParams["max-connections"] = "1"; storeParams["log-fd"] = "4"; if (!bestMachine->sshKey.empty()) { storeParams["ssh-key"] = bestMachine->sshKey; } } sshStore = openStore(bestMachine->storeUri, storeParams); sshStore->connect(); storeUri = bestMachine->storeUri; } catch (std::exception& e) { auto msg = absl::StripTrailingAsciiWhitespace(drainFD(5, false)); LOG(ERROR) << "cannot build on '" << bestMachine->storeUri << "': " << e.what() << (msg.empty() ? "" : absl::StrCat(": ", msg)); bestMachine->enabled = false; continue; } goto connected; } } connected: close(5); std::cerr << "# accept\n" << storeUri << "\n"; auto inputs = readStrings<PathSet>(source); auto outputs = readStrings<PathSet>(source); AutoCloseFD uploadLock = openLockFile( currentLoad + "/" + escapeUri(storeUri) + ".upload-lock", true); { DLOG(INFO) << "waiting for the upload lock to '" << storeUri << "'"; auto old = signal(SIGALRM, handleAlarm); alarm(15 * 60); if (!lockFile(uploadLock.get(), ltWrite, true)) { LOG(ERROR) << "somebody is hogging the upload lock, continuing..."; } alarm(0); signal(SIGALRM, old); } auto substitute = settings.buildersUseSubstitutes ? Substitute : NoSubstitute; { DLOG(INFO) << "copying dependencies to '" << storeUri << "'"; copyPaths(store, ref<Store>(sshStore), inputs, NoRepair, NoCheckSigs, substitute); } uploadLock = -1; BasicDerivation drv( readDerivation(store->realStoreDir + "/" + baseNameOf(drvPath))); drv.inputSrcs = inputs; auto result = sshStore->buildDerivation(drvPath, drv); if (!result.success()) { throw Error("build of '%s' on '%s' failed: %s", drvPath, storeUri, result.errorMsg); } PathSet missing; for (auto& path : outputs) { if (!store->isValidPath(path)) { missing.insert(path); } } if (!missing.empty()) { DLOG(INFO) << "copying outputs from '" << storeUri << "'"; store->locksHeld.insert(missing.begin(), missing.end()); /* FIXME: ugly */ copyPaths(ref<Store>(sshStore), store, missing, NoRepair, NoCheckSigs, NoSubstitute); } return 0; } } static RegisterLegacyCommand s1("build-remote", _main);