From 5cd72598feaff3c4bbcc7304a4844768f64a1ee0 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Wed, 30 Mar 2022 16:31:01 +0200 Subject: [PATCH] Add support for impure derivations Impure derivations are derivations that can produce a different result every time they're built. Example: stdenv.mkDerivation { name = "impure"; __impure = true; # marks this derivation as impure outputHashAlgo = "sha256"; outputHashMode = "recursive"; buildCommand = "date > $out"; }; Some important characteristics: * This requires the 'impure-derivations' experimental feature. * Impure derivations are not "cached". Thus, running "nix-build" on the example above multiple times will cause a rebuild every time. * They are implemented similar to CA derivations, i.e. the output is moved to a content-addressed path in the store. The difference is that we don't register a realisation in the Nix database. * Pure derivations are not allowed to depend on impure derivations. In the future fixed-output derivations will be allowed to depend on impure derivations, thus forming an "impurity barrier" in the dependency graph. * When sandboxing is enabled, impure derivations can access the network in the same way as fixed-output derivations. In relaxed sandboxing mode, they can access the local filesystem. --- src/libexpr/eval.cc | 1 + src/libexpr/eval.hh | 2 +- src/libexpr/primops.cc | 32 ++- src/libstore/build/derivation-goal.cc | 182 +++++++++------ src/libstore/build/derivation-goal.hh | 7 + src/libstore/build/local-derivation-goal.cc | 21 +- src/libstore/derivations.cc | 235 +++++++++++++++----- src/libstore/derivations.hh | 52 ++++- src/libstore/local-store.cc | 3 + src/libstore/path.cc | 9 + src/libstore/path.hh | 2 + src/libutil/experimental-features.cc | 1 + src/libutil/experimental-features.hh | 1 + src/nix/show-derivation.cc | 4 + tests/impure-derivations.nix | 46 ++++ tests/impure-derivations.sh | 39 ++++ tests/local.mk | 3 +- 17 files changed, 486 insertions(+), 154 deletions(-) create mode 100644 tests/impure-derivations.nix create mode 100644 tests/impure-derivations.sh diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 437c7fc53..b87e06ef5 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -436,6 +436,7 @@ EvalState::EvalState( , sBuilder(symbols.create("builder")) , sArgs(symbols.create("args")) , sContentAddressed(symbols.create("__contentAddressed")) + , sImpure(symbols.create("__impure")) , sOutputHash(symbols.create("outputHash")) , sOutputHashAlgo(symbols.create("outputHashAlgo")) , sOutputHashMode(symbols.create("outputHashMode")) diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh index e7915dd99..7ed376e8d 100644 --- a/src/libexpr/eval.hh +++ b/src/libexpr/eval.hh @@ -78,7 +78,7 @@ public: sSystem, sOverrides, sOutputs, sOutputName, sIgnoreNulls, sFile, sLine, sColumn, sFunctor, sToString, sRight, sWrong, sStructuredAttrs, sBuilder, sArgs, - sContentAddressed, + sContentAddressed, sImpure, sOutputHash, sOutputHashAlgo, sOutputHashMode, sRecurseForDerivations, sDescription, sSelf, sEpsilon, sStartSet, sOperator, sKey, sPath, diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index 9f549e52f..eaf04320e 100644 --- a/src/libexpr/primops.cc +++ b/src/libexpr/primops.cc @@ -989,6 +989,7 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * * PathSet context; bool contentAddressed = false; + bool isImpure = false; std::optional outputHash; std::string outputHashAlgo; auto ingestionMethod = FileIngestionMethod::Flat; @@ -1051,6 +1052,12 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * * settings.requireExperimentalFeature(Xp::CaDerivations); } + else if (i->name == state.sImpure) { + isImpure = state.forceBool(*i->value, pos); + if (isImpure) + settings.requireExperimentalFeature(Xp::ImpureDerivations); + } + /* The `args' attribute is special: it supplies the command-line arguments to the builder. */ else if (i->name == state.sArgs) { @@ -1197,15 +1204,28 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * * }); } - else if (contentAddressed) { + else if (contentAddressed || isImpure) { + if (contentAddressed && isImpure) + throw EvalError({ + .msg = hintfmt("derivation cannot be both content-addressed and impure"), + .errPos = posDrvName + }); + HashType ht = parseHashType(outputHashAlgo); for (auto & i : outputs) { drv.env[i] = hashPlaceholder(i); - drv.outputs.insert_or_assign(i, - DerivationOutput::CAFloating { - .method = ingestionMethod, - .hashType = ht, - }); + if (isImpure) + drv.outputs.insert_or_assign(i, + DerivationOutput::Impure { + .method = ingestionMethod, + .hashType = ht, + }); + else + drv.outputs.insert_or_assign(i, + DerivationOutput::CAFloating { + .method = ingestionMethod, + .hashType = ht, + }); } } diff --git a/src/libstore/build/derivation-goal.cc b/src/libstore/build/derivation-goal.cc index 3d1c4fbc1..2f3490829 100644 --- a/src/libstore/build/derivation-goal.cc +++ b/src/libstore/build/derivation-goal.cc @@ -204,9 +204,34 @@ void DerivationGoal::haveDerivation() { trace("have derivation"); + parsedDrv = std::make_unique(drvPath, *drv); + if (!drv->type().hasKnownOutputPaths()) settings.requireExperimentalFeature(Xp::CaDerivations); + if (!drv->type().isPure()) { + settings.requireExperimentalFeature(Xp::ImpureDerivations); + + for (auto & [outputName, output] : drv->outputs) { + auto randomPath = StorePath::random(outputPathName(drv->name, outputName)); + assert(!worker.store.isValidPath(randomPath)); + initialOutputs.insert({ + outputName, + InitialOutput { + .wanted = true, + .outputHash = impureOutputHash, + .known = InitialOutputStatus { + .path = randomPath, + .status = PathStatus::Absent + } + } + }); + } + + gaveUpOnSubstitution(); + return; + } + for (auto & i : drv->outputsAndOptPaths(worker.store)) if (i.second.second) worker.store.addTempRoot(*i.second.second); @@ -230,9 +255,6 @@ void DerivationGoal::haveDerivation() return; } - parsedDrv = std::make_unique(drvPath, *drv); - - /* We are first going to try to create the invalid output paths through substitutes. If that doesn't work, we'll build them. */ @@ -266,6 +288,8 @@ void DerivationGoal::outputsSubstitutionTried() { trace("all outputs substituted (maybe)"); + assert(drv->type().isPure()); + if (nrFailed > 0 && nrFailed > nrNoSubstituters + nrIncompleteClosure && !settings.tryFallback) { done(BuildResult::TransientFailure, {}, Error("some substitutes for the outputs of derivation '%s' failed (usually happens due to networking issues); try '--fallback' to build derivation from source ", @@ -315,9 +339,21 @@ void DerivationGoal::outputsSubstitutionTried() void DerivationGoal::gaveUpOnSubstitution() { /* The inputs must be built before we can build this goal. */ + inputDrvOutputs.clear(); if (useDerivation) - for (auto & i : dynamic_cast(drv.get())->inputDrvs) + for (auto & i : dynamic_cast(drv.get())->inputDrvs) { + /* Ensure that pure derivations don't depend on impure + derivations. */ + if (drv->type().isPure()) { + auto inputDrv = worker.evalStore.readDerivation(i.first); + if (!inputDrv.type().isPure()) + throw Error("pure derivation '%s' depends on impure derivation '%s'", + worker.store.printStorePath(drvPath), + worker.store.printStorePath(i.first)); + } + addWaitee(worker.makeDerivationGoal(i.first, i.second, buildMode == bmRepair ? bmRepair : bmNormal)); + } /* Copy the input sources from the eval store to the build store. */ @@ -345,6 +381,8 @@ void DerivationGoal::gaveUpOnSubstitution() void DerivationGoal::repairClosure() { + assert(drv->type().isPure()); + /* If we're repairing, we now know that our own outputs are valid. Now check whether the other paths in the outputs closure are good. If not, then start derivation goals for the derivations @@ -452,22 +490,24 @@ void DerivationGoal::inputsRealised() drvs. */ : true); }, + [&](const DerivationType::Impure &) { + return true; + } }, drvType.raw()); - if (resolveDrv) - { + if (resolveDrv && !fullDrv.inputDrvs.empty()) { settings.requireExperimentalFeature(Xp::CaDerivations); /* We are be able to resolve this derivation based on the - now-known results of dependencies. If so, we become a stub goal - aliasing that resolved derivation goal */ - std::optional attempt = fullDrv.tryResolve(worker.store); + now-known results of dependencies. If so, we become a + stub goal aliasing that resolved derivation goal. */ + std::optional attempt = fullDrv.tryResolve(worker.store, inputDrvOutputs); assert(attempt); Derivation drvResolved { *std::move(attempt) }; auto pathResolved = writeDerivation(worker.store, drvResolved); - auto msg = fmt("Resolved derivation: '%s' -> '%s'", + auto msg = fmt("resolved derivation: '%s' -> '%s'", worker.store.printStorePath(drvPath), worker.store.printStorePath(pathResolved)); act = std::make_unique(*logger, lvlInfo, actBuildWaiting, msg, @@ -488,21 +528,13 @@ void DerivationGoal::inputsRealised() /* Add the relevant output closures of the input derivation `i' as input paths. Only add the closures of output paths that are specified as inputs. */ - assert(worker.evalStore.isValidPath(drvPath)); - auto outputs = worker.evalStore.queryPartialDerivationOutputMap(depDrvPath); - for (auto & j : wantedDepOutputs) { - if (outputs.count(j) > 0) { - auto optRealizedInput = outputs.at(j); - if (!optRealizedInput) - throw Error( - "derivation '%s' requires output '%s' from input derivation '%s', which is supposedly realized already, yet we still don't know what path corresponds to that output", - worker.store.printStorePath(drvPath), j, worker.store.printStorePath(depDrvPath)); - worker.store.computeFSClosure(*optRealizedInput, inputPaths); - } else + for (auto & j : wantedDepOutputs) + if (auto outPath = get(inputDrvOutputs, { depDrvPath, j })) + worker.store.computeFSClosure(*outPath, inputPaths); + else throw Error( "derivation '%s' requires non-existent output '%s' from input derivation '%s'", worker.store.printStorePath(drvPath), j, worker.store.printStorePath(depDrvPath)); - } } } @@ -923,7 +955,7 @@ void DerivationGoal::buildDone() st = dynamic_cast(&e) ? BuildResult::NotDeterministic : statusOk(status) ? BuildResult::OutputRejected : - derivationType.isImpure() || diskFull ? BuildResult::TransientFailure : + derivationType.needsNetworkAccess() || diskFull ? BuildResult::TransientFailure : BuildResult::PermanentFailure; } @@ -934,60 +966,52 @@ void DerivationGoal::buildDone() void DerivationGoal::resolvedFinished() { + trace("resolved derivation finished"); + assert(resolvedDrvGoal); auto resolvedDrv = *resolvedDrvGoal->drv; - - auto resolvedHashes = staticOutputHashes(worker.store, resolvedDrv); - - StorePathSet outputPaths; - - // `wantedOutputs` might be empty, which means “all the outputs” - auto realWantedOutputs = wantedOutputs; - if (realWantedOutputs.empty()) - realWantedOutputs = resolvedDrv.outputNames(); + auto & resolvedResult = resolvedDrvGoal->buildResult; DrvOutputs builtOutputs; - for (auto & wantedOutput : realWantedOutputs) { - assert(initialOutputs.count(wantedOutput) != 0); - assert(resolvedHashes.count(wantedOutput) != 0); - auto realisation = worker.store.queryRealisation( - DrvOutput{resolvedHashes.at(wantedOutput), wantedOutput} - ); - // We've just built it, but maybe the build failed, in which case the - // realisation won't be there - if (realisation) { - auto newRealisation = *realisation; - newRealisation.id = DrvOutput{initialOutputs.at(wantedOutput).outputHash, wantedOutput}; - newRealisation.signatures.clear(); - newRealisation.dependentRealisations = drvOutputReferences(worker.store, *drv, realisation->outPath); - signRealisation(newRealisation); - worker.store.registerDrvOutput(newRealisation); - outputPaths.insert(realisation->outPath); - builtOutputs.emplace(realisation->id, *realisation); - } else { - // If we don't have a realisation, then it must mean that something - // failed when building the resolved drv - assert(!buildResult.success()); + if (resolvedResult.success()) { + auto resolvedHashes = staticOutputHashes(worker.store, resolvedDrv); + + StorePathSet outputPaths; + + // `wantedOutputs` might be empty, which means “all the outputs” + auto realWantedOutputs = wantedOutputs; + if (realWantedOutputs.empty()) + realWantedOutputs = resolvedDrv.outputNames(); + + for (auto & wantedOutput : realWantedOutputs) { + assert(initialOutputs.count(wantedOutput) != 0); + assert(resolvedHashes.count(wantedOutput) != 0); + auto realisation = resolvedResult.builtOutputs.at( + DrvOutput { resolvedHashes.at(wantedOutput), wantedOutput }); + if (drv->type().isPure()) { + auto newRealisation = realisation; + newRealisation.id = DrvOutput { initialOutputs.at(wantedOutput).outputHash, wantedOutput }; + newRealisation.signatures.clear(); + newRealisation.dependentRealisations = drvOutputReferences(worker.store, *drv, realisation.outPath); + signRealisation(newRealisation); + worker.store.registerDrvOutput(newRealisation); + } + outputPaths.insert(realisation.outPath); + builtOutputs.emplace(realisation.id, realisation); } + + runPostBuildHook( + worker.store, + *logger, + drvPath, + outputPaths + ); } - runPostBuildHook( - worker.store, - *logger, - drvPath, - outputPaths - ); - - auto status = [&]() { - auto & resolvedResult = resolvedDrvGoal->buildResult; - switch (resolvedResult.status) { - case BuildResult::AlreadyValid: - return BuildResult::ResolvesToAlreadyValid; - default: - return resolvedResult.status; - } - }(); + auto status = resolvedResult.status; + if (status == BuildResult::AlreadyValid) + status = BuildResult::ResolvesToAlreadyValid; done(status, std::move(builtOutputs)); } @@ -1236,6 +1260,7 @@ void DerivationGoal::flushLine() std::map> DerivationGoal::queryPartialDerivationOutputMap() { + assert(drv->type().isPure()); if (!useDerivation || drv->type().hasKnownOutputPaths()) { std::map> res; for (auto & [name, output] : drv->outputs) @@ -1248,6 +1273,7 @@ std::map> DerivationGoal::queryPartialDeri OutputPathMap DerivationGoal::queryDerivationOutputMap() { + assert(drv->type().isPure()); if (!useDerivation || drv->type().hasKnownOutputPaths()) { OutputPathMap res; for (auto & [name, output] : drv->outputsAndOptPaths(worker.store)) @@ -1261,6 +1287,8 @@ OutputPathMap DerivationGoal::queryDerivationOutputMap() std::pair DerivationGoal::checkPathValidity() { + if (!drv->type().isPure()) return { false, {} }; + bool checkHash = buildMode == bmRepair; auto wantedOutputsLeft = wantedOutputs; DrvOutputs validOutputs; @@ -1304,6 +1332,7 @@ std::pair DerivationGoal::checkPathValidity() if (info.wanted && info.known && info.known->isValid()) validOutputs.emplace(drvOutput, Realisation { drvOutput, info.known->path }); } + // If we requested all the outputs via the empty set, we are always fine. // If we requested specific elements, the loop above removes all the valid // ones, so any that are left must be invalid. @@ -1343,7 +1372,6 @@ void DerivationGoal::done( if (ex) // FIXME: strip: "error: " buildResult.errorMsg = ex->what(); - amDone(buildResult.success() ? ecSuccess : ecFailed, ex); if (buildResult.status == BuildResult::TimedOut) worker.timedOut = true; if (buildResult.status == BuildResult::PermanentFailure) @@ -1370,7 +1398,21 @@ void DerivationGoal::done( fs.open(traceBuiltOutputsFile, std::fstream::out); fs << worker.store.printStorePath(drvPath) << "\t" << buildResult.toString() << std::endl; } + + amDone(buildResult.success() ? ecSuccess : ecFailed, ex); } +void DerivationGoal::waiteeDone(GoalPtr waitee, ExitCode result) +{ + Goal::waiteeDone(waitee, result); + + if (waitee->buildResult.success()) + if (auto bfd = std::get_if(&waitee->buildResult.path)) + for (auto & [output, realisation] : waitee->buildResult.builtOutputs) + inputDrvOutputs.insert_or_assign( + { bfd->drvPath, output.outputName }, + realisation.outPath); +} + } diff --git a/src/libstore/build/derivation-goal.hh b/src/libstore/build/derivation-goal.hh index f556b6f25..2d8bfd592 100644 --- a/src/libstore/build/derivation-goal.hh +++ b/src/libstore/build/derivation-goal.hh @@ -57,6 +57,11 @@ struct DerivationGoal : public Goal them. */ StringSet wantedOutputs; + /* Mapping from input derivations + output names to actual store + paths. This is filled in by waiteeDone() as each dependency + finishes, before inputsRealised() is reached, */ + std::map, StorePath> inputDrvOutputs; + /* Whether additional wanted outputs have been added. */ bool needRestart = false; @@ -224,6 +229,8 @@ struct DerivationGoal : public Goal DrvOutputs builtOutputs = {}, std::optional ex = {}); + void waiteeDone(GoalPtr waitee, ExitCode result) override; + StorePathSet exportReferences(const StorePathSet & storePaths); }; diff --git a/src/libstore/build/local-derivation-goal.cc b/src/libstore/build/local-derivation-goal.cc index b176f318b..a6c07314f 100644 --- a/src/libstore/build/local-derivation-goal.cc +++ b/src/libstore/build/local-derivation-goal.cc @@ -395,7 +395,7 @@ void LocalDerivationGoal::startBuilder() else if (settings.sandboxMode == smDisabled) useChroot = false; else if (settings.sandboxMode == smRelaxed) - useChroot = !(derivationType.isImpure()) && !noChroot; + useChroot = !derivationType.needsNetworkAccess() && !noChroot; } auto & localStore = getLocalStore(); @@ -608,7 +608,7 @@ void LocalDerivationGoal::startBuilder() "nogroup:x:65534:\n", sandboxGid())); /* Create /etc/hosts with localhost entry. */ - if (!(derivationType.isImpure())) + if (!derivationType.needsNetworkAccess()) writeFile(chrootRootDir + "/etc/hosts", "127.0.0.1 localhost\n::1 localhost\n"); /* Make the closure of the inputs available in the chroot, @@ -796,7 +796,7 @@ void LocalDerivationGoal::startBuilder() us. */ - if (!(derivationType.isImpure())) + if (!derivationType.needsNetworkAccess()) privateNetwork = true; userNamespaceSync.create(); @@ -1060,7 +1060,7 @@ void LocalDerivationGoal::initEnv() to the builder is generally impure, but the output of fixed-output derivations is by definition pure (since we already know the cryptographic hash of the output). */ - if (derivationType.isImpure()) { + if (derivationType.needsNetworkAccess()) { for (auto & i : parsedDrv->getStringsAttr("impureEnvVars").value_or(Strings())) env[i] = getEnv(i).value_or(""); } @@ -1674,7 +1674,7 @@ void LocalDerivationGoal::runChild() /* Fixed-output derivations typically need to access the network, so give them access to /etc/resolv.conf and so on. */ - if (derivationType.isImpure()) { + if (derivationType.needsNetworkAccess()) { // Only use nss functions to resolve hosts and // services. Don’t use it for anything else that may // be configured for this system. This limits the @@ -2399,6 +2399,13 @@ DrvOutputs LocalDerivationGoal::registerOutputs() assert(false); }, + [&](const DerivationOutput::Impure & doi) { + return newInfoFromCA(DerivationOutput::CAFloating { + .method = doi.method, + .hashType = doi.hashType, + }); + }, + }, output.raw()); /* FIXME: set proper permissions in restorePath() so @@ -2609,7 +2616,9 @@ DrvOutputs LocalDerivationGoal::registerOutputs() }, .outPath = newInfo.path }; - if (settings.isExperimentalFeatureEnabled(Xp::CaDerivations)) { + if (settings.isExperimentalFeatureEnabled(Xp::CaDerivations) + && drv->type().isPure()) + { signRealisation(thisRealisation); worker.store.registerDrvOutput(thisRealisation); } diff --git a/src/libstore/derivations.cc b/src/libstore/derivations.cc index 85d75523f..75e0178bb 100644 --- a/src/libstore/derivations.cc +++ b/src/libstore/derivations.cc @@ -25,26 +25,42 @@ std::optional DerivationOutput::path(const Store & store, std::string [](const DerivationOutput::Deferred &) -> std::optional { return std::nullopt; }, + [](const DerivationOutput::Impure &) -> std::optional { + return std::nullopt; + }, }, raw()); } -StorePath DerivationOutput::CAFixed::path(const Store & store, std::string_view drvName, std::string_view outputName) const { +StorePath DerivationOutput::CAFixed::path(const Store & store, std::string_view drvName, std::string_view outputName) const +{ return store.makeFixedOutputPath( hash.method, hash.hash, outputPathName(drvName, outputName)); } -bool DerivationType::isCA() const { +bool DerivationType::isCA() const +{ /* Normally we do the full `std::visit` to make sure we have exhaustively handled all variants, but so long as there is a variant called `ContentAddressed`, it must be the only one for which `isCA` is true for this to make sense!. */ - return std::holds_alternative(raw()); + return std::visit(overloaded { + [](const InputAddressed & ia) { + return false; + }, + [](const ContentAddressed & ca) { + return true; + }, + [](const Impure &) { + return true; + }, + }, raw()); } -bool DerivationType::isFixed() const { +bool DerivationType::isFixed() const +{ return std::visit(overloaded { [](const InputAddressed & ia) { return false; @@ -52,10 +68,14 @@ bool DerivationType::isFixed() const { [](const ContentAddressed & ca) { return ca.fixed; }, + [](const Impure &) { + return false; + }, }, raw()); } -bool DerivationType::hasKnownOutputPaths() const { +bool DerivationType::hasKnownOutputPaths() const +{ return std::visit(overloaded { [](const InputAddressed & ia) { return !ia.deferred; @@ -63,11 +83,15 @@ bool DerivationType::hasKnownOutputPaths() const { [](const ContentAddressed & ca) { return ca.fixed; }, + [](const Impure &) { + return false; + }, }, raw()); } -bool DerivationType::isImpure() const { +bool DerivationType::needsNetworkAccess() const +{ return std::visit(overloaded { [](const InputAddressed & ia) { return false; @@ -75,6 +99,25 @@ bool DerivationType::isImpure() const { [](const ContentAddressed & ca) { return !ca.pure; }, + [](const Impure &) { + return true; + }, + }, raw()); +} + + +bool DerivationType::isPure() const +{ + return std::visit(overloaded { + [](const InputAddressed & ia) { + return true; + }, + [](const ContentAddressed & ca) { + return true; + }, + [](const Impure &) { + return false; + }, }, raw()); } @@ -176,7 +219,16 @@ static DerivationOutput parseDerivationOutput(const Store & store, hashAlgo = hashAlgo.substr(2); } const auto hashType = parseHashType(hashAlgo); - if (hash != "") { + if (hash == "impure") { + settings.requireExperimentalFeature(Xp::ImpureDerivations); + assert(pathS == ""); + return DerivationOutput { + .output = DerivationOutputImpure { + .method = std::move(method), + .hashType = std::move(hashType), + }, + }; + } else if (hash != "") { validatePath(pathS); return DerivationOutput::CAFixed { .hash = FixedOutputHash { @@ -345,6 +397,12 @@ std::string Derivation::unparse(const Store & store, bool maskOutputs, s += ','; printUnquotedString(s, ""); s += ','; printUnquotedString(s, ""); s += ','; printUnquotedString(s, ""); + }, + [&](const DerivationOutputImpure & doi) { + // FIXME + s += ','; printUnquotedString(s, ""); + s += ','; printUnquotedString(s, makeFileIngestionPrefix(doi.method) + printHashType(doi.hashType)); + s += ','; printUnquotedString(s, "impure"); } }, i.second.raw()); s += ')'; @@ -410,8 +468,14 @@ std::string outputPathName(std::string_view drvName, std::string_view outputName DerivationType BasicDerivation::type() const { - std::set inputAddressedOutputs, fixedCAOutputs, floatingCAOutputs, deferredIAOutputs; + std::set + inputAddressedOutputs, + fixedCAOutputs, + floatingCAOutputs, + deferredIAOutputs, + impureOutputs; std::optional floatingHashType; + for (auto & i : outputs) { std::visit(overloaded { [&](const DerivationOutput::InputAddressed &) { @@ -426,43 +490,78 @@ DerivationType BasicDerivation::type() const floatingHashType = dof.hashType; } else { if (*floatingHashType != dof.hashType) - throw Error("All floating outputs must use the same hash type"); + throw Error("all floating outputs must use the same hash type"); } }, [&](const DerivationOutput::Deferred &) { - deferredIAOutputs.insert(i.first); + deferredIAOutputs.insert(i.first); + }, + [&](const DerivationOutput::Impure &) { + impureOutputs.insert(i.first); }, }, i.second.raw()); } - if (inputAddressedOutputs.empty() && fixedCAOutputs.empty() && floatingCAOutputs.empty() && deferredIAOutputs.empty()) { - throw Error("Must have at least one output"); - } else if (! inputAddressedOutputs.empty() && fixedCAOutputs.empty() && floatingCAOutputs.empty() && deferredIAOutputs.empty()) { + if (inputAddressedOutputs.empty() + && fixedCAOutputs.empty() + && floatingCAOutputs.empty() + && deferredIAOutputs.empty() + && impureOutputs.empty()) + throw Error("must have at least one output"); + + if (!inputAddressedOutputs.empty() + && fixedCAOutputs.empty() + && floatingCAOutputs.empty() + && deferredIAOutputs.empty() + && impureOutputs.empty()) return DerivationType::InputAddressed { .deferred = false, }; - } else if (inputAddressedOutputs.empty() && ! fixedCAOutputs.empty() && floatingCAOutputs.empty() && deferredIAOutputs.empty()) { + + if (inputAddressedOutputs.empty() + && !fixedCAOutputs.empty() + && floatingCAOutputs.empty() + && deferredIAOutputs.empty() + && impureOutputs.empty()) + { if (fixedCAOutputs.size() > 1) // FIXME: Experimental feature? - throw Error("Only one fixed output is allowed for now"); + throw Error("only one fixed output is allowed for now"); if (*fixedCAOutputs.begin() != "out") - throw Error("Single fixed output must be named \"out\""); + throw Error("single fixed output must be named \"out\""); return DerivationType::ContentAddressed { .pure = false, .fixed = true, }; - } else if (inputAddressedOutputs.empty() && fixedCAOutputs.empty() && ! floatingCAOutputs.empty() && deferredIAOutputs.empty()) { + } + + if (inputAddressedOutputs.empty() + && fixedCAOutputs.empty() + && !floatingCAOutputs.empty() + && deferredIAOutputs.empty() + && impureOutputs.empty()) return DerivationType::ContentAddressed { .pure = true, .fixed = false, }; - } else if (inputAddressedOutputs.empty() && fixedCAOutputs.empty() && floatingCAOutputs.empty() && !deferredIAOutputs.empty()) { + + if (inputAddressedOutputs.empty() + && fixedCAOutputs.empty() + && floatingCAOutputs.empty() + && !deferredIAOutputs.empty() + && impureOutputs.empty()) return DerivationType::InputAddressed { .deferred = true, }; - } else { - throw Error("Can't mix derivation output types"); - } + + if (inputAddressedOutputs.empty() + && fixedCAOutputs.empty() + && floatingCAOutputs.empty() + && deferredIAOutputs.empty() + && !impureOutputs.empty()) + return DerivationType::Impure { }; + + throw Error("can't mix derivation output types"); } @@ -524,12 +623,22 @@ DrvHash hashDerivationModulo(Store & store, const Derivation & drv, bool maskOut + store.printStorePath(dof.path(store, drv.name, i.first))); outputHashes.insert_or_assign(i.first, std::move(hash)); } - return DrvHash{ + return DrvHash { .hashes = outputHashes, .kind = DrvHash::Kind::Regular, }; } + if (!type.isPure()) { + std::map outputHashes; + for (const auto & [outputName, _] : drv.outputs) + outputHashes.insert_or_assign(outputName, impureOutputHash); + return DrvHash { + .hashes = outputHashes, + .kind = DrvHash::Kind::Deferred, + }; + } + auto kind = std::visit(overloaded { [](const DerivationType::InputAddressed & ia) { /* This might be a "pesimistically" deferred output, so we don't @@ -541,6 +650,9 @@ DrvHash hashDerivationModulo(Store & store, const Derivation & drv, bool maskOut ? DrvHash::Kind::Regular : DrvHash::Kind::Deferred; }, + [](const DerivationType::Impure &) -> DrvHash::Kind { + assert(false); + } }, drv.type().raw()); std::map inputs2; @@ -599,7 +711,8 @@ StringSet BasicDerivation::outputNames() const return names; } -DerivationOutputsAndOptPaths BasicDerivation::outputsAndOptPaths(const Store & store) const { +DerivationOutputsAndOptPaths BasicDerivation::outputsAndOptPaths(const Store & store) const +{ DerivationOutputsAndOptPaths outsAndOptPaths; for (auto output : outputs) outsAndOptPaths.insert(std::make_pair( @@ -610,7 +723,8 @@ DerivationOutputsAndOptPaths BasicDerivation::outputsAndOptPaths(const Store & s return outsAndOptPaths; } -std::string_view BasicDerivation::nameFromPath(const StorePath & drvPath) { +std::string_view BasicDerivation::nameFromPath(const StorePath & drvPath) +{ auto nameWithSuffix = drvPath.name(); constexpr std::string_view extension = ".drv"; assert(hasSuffix(nameWithSuffix, extension)); @@ -672,6 +786,11 @@ void writeDerivation(Sink & out, const Store & store, const BasicDerivation & dr << "" << ""; }, + [&](const DerivationOutput::Impure & doi) { + out << "" + << (makeFileIngestionPrefix(doi.method) + printHashType(doi.hashType)) + << "impure"; + }, }, i.second.raw()); } worker_proto::write(store, out, drv.inputSrcs); @@ -697,21 +816,19 @@ std::string downstreamPlaceholder(const Store & store, const StorePath & drvPath } -static void rewriteDerivation(Store & store, BasicDerivation & drv, const StringMap & rewrites) { - - debug("Rewriting the derivation"); - - for (auto &rewrite: rewrites) { +static void rewriteDerivation(Store & store, BasicDerivation & drv, const StringMap & rewrites) +{ + for (auto & rewrite : rewrites) { debug("rewriting %s as %s", rewrite.first, rewrite.second); } drv.builder = rewriteStrings(drv.builder, rewrites); - for (auto & arg: drv.args) { + for (auto & arg : drv.args) { arg = rewriteStrings(arg, rewrites); } StringPairs newEnv; - for (auto & envVar: drv.env) { + for (auto & envVar : drv.env) { auto envName = rewriteStrings(envVar.first, rewrites); auto envValue = rewriteStrings(envVar.second, rewrites); newEnv.emplace(envName, envValue); @@ -732,48 +849,48 @@ static void rewriteDerivation(Store & store, BasicDerivation & drv, const String } -static bool tryResolveInput( - Store & store, StorePathSet & inputSrcs, StringMap & inputRewrites, - const StorePath & inputDrv, const StringSet & inputOutputs) +std::optional Derivation::tryResolve(Store & store) const { - auto inputDrvOutputs = store.queryPartialDerivationOutputMap(inputDrv); + std::map, StorePath> inputDrvOutputs; - auto getOutput = [&](const std::string & outputName) { - auto & actualPathOpt = inputDrvOutputs.at(outputName); - if (!actualPathOpt) - warn("output %s of input %s missing, aborting the resolving", - outputName, - store.printStorePath(inputDrv) - ); - return actualPathOpt; - }; + for (auto & input : inputDrvs) + for (auto & [outputName, outputPath] : store.queryPartialDerivationOutputMap(input.first)) + if (outputPath) + inputDrvOutputs.insert_or_assign({input.first, outputName}, *outputPath); - for (auto & outputName : inputOutputs) { - auto actualPathOpt = getOutput(outputName); - if (!actualPathOpt) return false; - auto actualPath = *actualPathOpt; - inputRewrites.emplace( - downstreamPlaceholder(store, inputDrv, outputName), - store.printStorePath(actualPath)); - inputSrcs.insert(std::move(actualPath)); - } - - return true; + return tryResolve(store, inputDrvOutputs); } -std::optional Derivation::tryResolve(Store & store) { +std::optional Derivation::tryResolve( + Store & store, + const std::map, StorePath> & inputDrvOutputs) const +{ BasicDerivation resolved { *this }; // Input paths that we'll want to rewrite in the derivation StringMap inputRewrites; - for (auto & [inputDrv, inputOutputs] : inputDrvs) - if (!tryResolveInput(store, resolved.inputSrcs, inputRewrites, inputDrv, inputOutputs)) - return std::nullopt; + for (auto & [inputDrv, inputOutputs] : inputDrvs) { + for (auto & outputName : inputOutputs) { + if (auto actualPath = get(inputDrvOutputs, { inputDrv, outputName })) { + inputRewrites.emplace( + downstreamPlaceholder(store, inputDrv, outputName), + store.printStorePath(*actualPath)); + resolved.inputSrcs.insert(*actualPath); + } else { + warn("output '%s' of input '%s' missing, aborting the resolving", + outputName, + store.printStorePath(inputDrv)); + return {}; + } + } + } rewriteDerivation(store, resolved, inputRewrites); return resolved; } +const Hash impureOutputHash = hashString(htSHA256, "impure"); + } diff --git a/src/libstore/derivations.hh b/src/libstore/derivations.hh index 63ea5ef76..b62e40786 100644 --- a/src/libstore/derivations.hh +++ b/src/libstore/derivations.hh @@ -41,15 +41,26 @@ struct DerivationOutputCAFloating }; /* Input-addressed output which depends on a (CA) derivation whose hash isn't - * known atm + * known yet. */ struct DerivationOutputDeferred {}; +/* Impure output which is moved to a content-addressed location (like + CAFloating) but isn't registered as a realization. + */ +struct DerivationOutputImpure +{ + /* information used for expected hash computation */ + FileIngestionMethod method; + HashType hashType; +}; + typedef std::variant< DerivationOutputInputAddressed, DerivationOutputCAFixed, DerivationOutputCAFloating, - DerivationOutputDeferred + DerivationOutputDeferred, + DerivationOutputImpure > _DerivationOutputRaw; struct DerivationOutput : _DerivationOutputRaw @@ -61,6 +72,7 @@ struct DerivationOutput : _DerivationOutputRaw using CAFixed = DerivationOutputCAFixed; using CAFloating = DerivationOutputCAFloating; using Deferred = DerivationOutputDeferred; + using Impure = DerivationOutputImpure; /* Note, when you use this function you should make sure that you're passing the right derivation name. When in doubt, you should use the safer @@ -94,9 +106,13 @@ struct DerivationType_ContentAddressed { bool fixed; }; +struct DerivationType_Impure { +}; + typedef std::variant< DerivationType_InputAddressed, - DerivationType_ContentAddressed + DerivationType_ContentAddressed, + DerivationType_Impure > _DerivationTypeRaw; struct DerivationType : _DerivationTypeRaw { @@ -104,7 +120,7 @@ struct DerivationType : _DerivationTypeRaw { using Raw::Raw; using InputAddressed = DerivationType_InputAddressed; using ContentAddressed = DerivationType_ContentAddressed; - + using Impure = DerivationType_Impure; /* Do the outputs of the derivation have paths calculated from their content, or from the derivation itself? */ @@ -114,10 +130,13 @@ struct DerivationType : _DerivationTypeRaw { non-CA derivations. */ bool isFixed() const; - /* Is the derivation impure and needs to access non-deterministic resources, or - pure and can be sandboxed? Note that whether or not we actually sandbox the - derivation is controlled separately. Never true for non-CA derivations. */ - bool isImpure() const; + /* Whether the derivation needs to access the network. Note that + whether or not we actually sandbox the derivation is controlled + separately. Never true for non-CA derivations. */ + bool needsNetworkAccess() const; + + /* FIXME */ + bool isPure() const; /* Does the derivation knows its own output paths? Only true when there's no floating-ca derivation involved in the @@ -173,7 +192,14 @@ struct Derivation : BasicDerivation added directly to input sources. 2. Input placeholders are replaced with realized input store paths. */ - std::optional tryResolve(Store & store); + std::optional tryResolve(Store & store) const; + + /* Like the above, but instead of querying the Nix database for + realisations, uses a given mapping from input derivation paths + + output names to actual output store paths. */ + std::optional tryResolve( + Store & store, + const std::map, StorePath> & inputDrvOutputs) const; Derivation() = default; Derivation(const BasicDerivation & bd) : BasicDerivation(bd) { } @@ -211,7 +237,7 @@ std::string outputPathName(std::string_view drvName, std::string_view outputName struct DrvHash { std::map hashes; - enum struct Kind: bool { + enum struct Kind : bool { // Statically determined derivations. // This hash will be directly used to compute the output paths Regular, @@ -252,8 +278,10 @@ DrvHash hashDerivationModulo(Store & store, const Derivation & drv, bool maskOut /* Return a map associating each output to a hash that uniquely identifies its derivation (modulo the self-references). + + FIXME: what is the Hash in this map? */ -std::map staticOutputHashes(Store& store, const Derivation& drv); +std::map staticOutputHashes(Store & store, const Derivation & drv); /* Memoisation of hashDerivationModulo(). */ typedef std::map DrvHashes; @@ -286,4 +314,6 @@ std::string hashPlaceholder(const std::string_view outputName); dependency which is a CA derivation. */ std::string downstreamPlaceholder(const Store & store, const StorePath & drvPath, std::string_view outputName); +extern const Hash impureOutputHash; + } diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc index 60fe53af1..d77fff963 100644 --- a/src/libstore/local-store.cc +++ b/src/libstore/local-store.cc @@ -719,6 +719,9 @@ void LocalStore::checkDerivationOutputs(const StorePath & drvPath, const Derivat [&](const DerivationOutput::Deferred &) { /* Nothing to check */ }, + [&](const DerivationOutput::Impure &) { + /* Nothing to check */ + }, }, i.second.raw()); } } diff --git a/src/libstore/path.cc b/src/libstore/path.cc index e642abcd5..392db225e 100644 --- a/src/libstore/path.cc +++ b/src/libstore/path.cc @@ -1,5 +1,7 @@ #include "store-api.hh" +#include + namespace nix { static void checkName(std::string_view path, std::string_view name) @@ -41,6 +43,13 @@ bool StorePath::isDerivation() const StorePath StorePath::dummy("ffffffffffffffffffffffffffffffff-x"); +StorePath StorePath::random(std::string_view name) +{ + Hash hash(htSHA1); + randombytes_buf(hash.hash, hash.hashSize); + return StorePath(hash, name); +} + StorePath Store::parseStorePath(std::string_view path) const { auto p = canonPath(std::string(path)); diff --git a/src/libstore/path.hh b/src/libstore/path.hh index e65fee622..77fd0f8dc 100644 --- a/src/libstore/path.hh +++ b/src/libstore/path.hh @@ -58,6 +58,8 @@ public: } static StorePath dummy; + + static StorePath random(std::string_view name); }; typedef std::set StorePathSet; diff --git a/src/libutil/experimental-features.cc b/src/libutil/experimental-features.cc index 01f318fa3..e033a4116 100644 --- a/src/libutil/experimental-features.cc +++ b/src/libutil/experimental-features.cc @@ -7,6 +7,7 @@ namespace nix { std::map stringifiedXpFeatures = { { Xp::CaDerivations, "ca-derivations" }, + { Xp::ImpureDerivations, "impure-derivations" }, { Xp::Flakes, "flakes" }, { Xp::NixCommand, "nix-command" }, { Xp::RecursiveNix, "recursive-nix" }, diff --git a/src/libutil/experimental-features.hh b/src/libutil/experimental-features.hh index b5140dcfe..3a254b423 100644 --- a/src/libutil/experimental-features.hh +++ b/src/libutil/experimental-features.hh @@ -16,6 +16,7 @@ namespace nix { enum struct ExperimentalFeature { CaDerivations, + ImpureDerivations, Flakes, NixCommand, RecursiveNix, diff --git a/src/nix/show-derivation.cc b/src/nix/show-derivation.cc index 0d9655732..fb46b4dbf 100644 --- a/src/nix/show-derivation.cc +++ b/src/nix/show-derivation.cc @@ -77,6 +77,10 @@ struct CmdShowDerivation : InstallablesCommand outputObj.attr("hashAlgo", makeFileIngestionPrefix(dof.method) + printHashType(dof.hashType)); }, [&](const DerivationOutput::Deferred &) {}, + [&](const DerivationOutput::Impure & doi) { + outputObj.attr("hashAlgo", makeFileIngestionPrefix(doi.method) + printHashType(doi.hashType)); + outputObj.attr("impure", true); + }, }, output.raw()); } } diff --git a/tests/impure-derivations.nix b/tests/impure-derivations.nix new file mode 100644 index 000000000..ba7d53146 --- /dev/null +++ b/tests/impure-derivations.nix @@ -0,0 +1,46 @@ +with import ./config.nix; + +rec { + + impure = mkDerivation { + name = "impure"; + outputs = [ "out" "stuff" ]; + buildCommand = + '' + x=$(< $TEST_ROOT/counter) + mkdir $out $stuff + echo $x > $out/n + ln -s $out/n $stuff/bla + printf $((x + 1)) > $TEST_ROOT/counter + ''; + __impure = true; + outputHashAlgo = "sha256"; + outputHashMode = "recursive"; + impureEnvVars = [ "TEST_ROOT" ]; + }; + + impureOnImpure = mkDerivation { + name = "impure-on-impure"; + buildCommand = + '' + x=$(< ${impure}/n) + mkdir $out + printf X$x > $out/n + ln -s ${impure.stuff} $out/symlink + ln -s $out $out/self + ''; + __impure = true; + outputHashAlgo = "sha256"; + outputHashMode = "recursive"; + }; + + # This is not allowed. + inputAddressed = mkDerivation { + name = "input-addressed"; + buildCommand = + '' + cat ${impure} > $out + ''; + }; + +} diff --git a/tests/impure-derivations.sh b/tests/impure-derivations.sh new file mode 100644 index 000000000..cb1eaf84a --- /dev/null +++ b/tests/impure-derivations.sh @@ -0,0 +1,39 @@ +source common.sh + +requireDaemonNewerThan "2.8pre20220311" + +enableFeatures "ca-derivations ca-references impure-derivations" + +clearStore + +# Basic test of impure derivations: building one a second time should not use the previous result. +printf 0 > $TEST_ROOT/counter + +json=$(nix build -L --no-link --json --file ./impure-derivations.nix impure) +path1=$(echo $json | jq -r .[].outputs.out) +path1_stuff=$(echo $json | jq -r .[].outputs.stuff) +[[ $(< $path1/n) = 0 ]] +[[ $(< $path1_stuff/bla) = 0 ]] + +[[ $(nix path-info --json $path1 | jq .[].ca) =~ fixed:r:sha256: ]] + +path2=$(nix build -L --no-link --json --file ./impure-derivations.nix impure | jq -r .[].outputs.out) +[[ $(< $path2/n) = 1 ]] + +# Test impure derivations that depend on impure derivations. +path3=$(nix build -L --no-link --json --file ./impure-derivations.nix impureOnImpure -vvvvv | jq -r .[].outputs.out) +[[ $(< $path3/n) = X2 ]] + +path4=$(nix build -L --no-link --json --file ./impure-derivations.nix impureOnImpure -vvvvv | jq -r .[].outputs.out) +[[ $(< $path4/n) = X3 ]] + +# Test that (self-)references work. +[[ $(< $path4/symlink/bla) = 3 ]] +[[ $(< $path4/self/n) = X3 ]] + +# Input-addressed derivations cannot depend on impure derivations directly. +nix build -L --no-link --json --file ./impure-derivations.nix inputAddressed 2>&1 | grep 'depends on impure derivation' + +drvPath=$(nix eval --json --file ./impure-derivations.nix impure.drvPath | jq -r .) +[[ $(nix show-derivation $drvPath | jq ".[\"$drvPath\"].outputs.out.impure") = true ]] +[[ $(nix show-derivation $drvPath | jq ".[\"$drvPath\"].outputs.stuff.impure") = true ]] diff --git a/tests/local.mk b/tests/local.mk index 97971dd76..668b34500 100644 --- a/tests/local.mk +++ b/tests/local.mk @@ -97,7 +97,8 @@ nix_tests = \ nix-profile.sh \ suggestions.sh \ store-ping.sh \ - fetchClosure.sh + fetchClosure.sh \ + impure-derivations.sh ifeq ($(HAVE_LIBCPUID), 1) nix_tests += compute-levels.sh