diff --git a/doc/manual/rl-next/nix-copy-flags.md b/doc/manual/rl-next/nix-copy-flags.md new file mode 100644 index 000000000..f5b2b9716 --- /dev/null +++ b/doc/manual/rl-next/nix-copy-flags.md @@ -0,0 +1,18 @@ +--- +synopsis: "`nix copy` supports `--profile` and `--out-link`" +prs: [11657] +--- + +The `nix copy` command now has flags `--profile` and `--out-link`, similar to `nix build`. `--profile` makes a profile point to the +top-level store path, while `--out-link` create symlinks to the top-level store paths. + +For example, when updating the local NixOS system profile from a NixOS system closure on a remote machine, instead of +``` +# nix copy --from ssh://server $path +# nix build --profile /nix/var/nix/profiles/system $path +``` +you can now do +``` +# nix copy --from ssh://server --profile /nix/var/nix/profiles/system $path +``` +The advantage is that this avoids a time window where *path* is not a garbage collector root, and so could be deleted by a concurrent `nix store gc` process. diff --git a/src/libcmd/command.cc b/src/libcmd/command.cc index 1a4c76ec5..86d13fab7 100644 --- a/src/libcmd/command.cc +++ b/src/libcmd/command.cc @@ -179,30 +179,34 @@ BuiltPathsCommand::BuiltPathsCommand(bool recursive) void BuiltPathsCommand::run(ref store, Installables && installables) { - BuiltPaths paths; + BuiltPaths rootPaths, allPaths; + if (all) { if (installables.size()) throw UsageError("'--all' does not expect arguments"); // XXX: Only uses opaque paths, ignores all the realisations for (auto & p : store->queryAllValidPaths()) - paths.emplace_back(BuiltPath::Opaque{p}); + rootPaths.emplace_back(BuiltPath::Opaque{p}); + allPaths = rootPaths; } else { - paths = Installable::toBuiltPaths(getEvalStore(), store, realiseMode, operateOn, installables); + rootPaths = Installable::toBuiltPaths(getEvalStore(), store, realiseMode, operateOn, installables); + allPaths = rootPaths; + if (recursive) { // XXX: This only computes the store path closure, ignoring // intermediate realisations StorePathSet pathsRoots, pathsClosure; - for (auto & root : paths) { + for (auto & root : rootPaths) { auto rootFromThis = root.outPaths(); pathsRoots.insert(rootFromThis.begin(), rootFromThis.end()); } store->computeFSClosure(pathsRoots, pathsClosure); for (auto & path : pathsClosure) - paths.emplace_back(BuiltPath::Opaque{path}); + allPaths.emplace_back(BuiltPath::Opaque{path}); } } - run(store, std::move(paths)); + run(store, std::move(allPaths), std::move(rootPaths)); } StorePathsCommand::StorePathsCommand(bool recursive) @@ -210,10 +214,10 @@ StorePathsCommand::StorePathsCommand(bool recursive) { } -void StorePathsCommand::run(ref store, BuiltPaths && paths) +void StorePathsCommand::run(ref store, BuiltPaths && allPaths, BuiltPaths && rootPaths) { StorePathSet storePaths; - for (auto & builtPath : paths) + for (auto & builtPath : allPaths) for (auto & p : builtPath.outPaths()) storePaths.insert(p); @@ -245,7 +249,7 @@ void MixProfile::updateProfile(const StorePath & storePath) { if (!profile) return; - auto store = getStore().dynamic_pointer_cast(); + auto store = getDstStore().dynamic_pointer_cast(); if (!store) throw Error("'--profile' is not supported for this Nix store"); auto profile2 = absPath(*profile); @@ -365,4 +369,31 @@ void MixEnvironment::setEnviron() return; } +void createOutLinks(const std::filesystem::path & outLink, const BuiltPaths & buildables, LocalFSStore & store) +{ + for (const auto & [_i, buildable] : enumerate(buildables)) { + auto i = _i; + std::visit( + overloaded{ + [&](const BuiltPath::Opaque & bo) { + auto symlink = outLink; + if (i) + symlink += fmt("-%d", i); + store.addPermRoot(bo.path, absPath(symlink.string())); + }, + [&](const BuiltPath::Built & bfd) { + for (auto & output : bfd.outputs) { + auto symlink = outLink; + if (i) + symlink += fmt("-%d", i); + if (output.first != "out") + symlink += fmt("-%s", output.first); + store.addPermRoot(output.second, absPath(symlink.string())); + } + }, + }, + buildable.raw()); + } +} + } diff --git a/src/libcmd/command.hh b/src/libcmd/command.hh index 8da4327c2..23529848f 100644 --- a/src/libcmd/command.hh +++ b/src/libcmd/command.hh @@ -18,6 +18,7 @@ extern char ** savedArgv; class EvalState; struct Pos; class Store; +class LocalFSStore; static constexpr Command::Category catHelp = -1; static constexpr Command::Category catSecondary = 100; @@ -46,7 +47,20 @@ struct StoreCommand : virtual Command { StoreCommand(); void run() override; + + /** + * Return the default Nix store. + */ ref getStore(); + + /** + * Return the destination Nix store. + */ + virtual ref getDstStore() + { + return getStore(); + } + virtual ref createStore(); /** * Main entry point, with a `Store` provided @@ -69,7 +83,7 @@ struct CopyCommand : virtual StoreCommand ref createStore() override; - ref getDstStore(); + ref getDstStore() override; }; /** @@ -239,7 +253,7 @@ public: BuiltPathsCommand(bool recursive = false); - virtual void run(ref store, BuiltPaths && paths) = 0; + virtual void run(ref store, BuiltPaths && allPaths, BuiltPaths && rootPaths) = 0; void run(ref store, Installables && installables) override; @@ -252,7 +266,7 @@ struct StorePathsCommand : public BuiltPathsCommand virtual void run(ref store, StorePaths && storePaths) = 0; - void run(ref store, BuiltPaths && paths) override; + void run(ref store, BuiltPaths && allPaths, BuiltPaths && rootPaths) override; }; /** @@ -354,4 +368,10 @@ std::string showVersions(const std::set & versions); void printClosureDiff( ref store, const StorePath & beforePath, const StorePath & afterPath, std::string_view indent); +/** + * Create symlinks prefixed by `outLink` to the store paths in + * `buildables`. + */ +void createOutLinks(const std::filesystem::path & outLink, const BuiltPaths & buildables, LocalFSStore & store); + } diff --git a/src/libcmd/installables.cc b/src/libcmd/installables.cc index 227bb64ed..f2b27af7c 100644 --- a/src/libcmd/installables.cc +++ b/src/libcmd/installables.cc @@ -918,4 +918,12 @@ void BuiltPathsCommand::applyDefaultInstallables(std::vector & rawI rawInstallables.push_back("."); } +BuiltPaths toBuiltPaths(const std::vector & builtPathsWithResult) +{ + BuiltPaths res; + for (auto & i : builtPathsWithResult) + res.push_back(i.path); + return res; +} + } diff --git a/src/libcmd/installables.hh b/src/libcmd/installables.hh index bf5759230..c995c3019 100644 --- a/src/libcmd/installables.hh +++ b/src/libcmd/installables.hh @@ -86,6 +86,8 @@ struct BuiltPathWithResult std::optional result; }; +BuiltPaths toBuiltPaths(const std::vector & builtPathsWithResult); + /** * Shorthand, for less typing and helping us keep the choice of * collection in sync. diff --git a/src/nix/build.cc b/src/nix/build.cc index da9132d02..3569b0cde 100644 --- a/src/nix/build.cc +++ b/src/nix/build.cc @@ -42,29 +42,6 @@ static nlohmann::json builtPathsWithResultToJSON(const std::vector& buildables, LocalFSStore& store2) -{ - for (const auto & [_i, buildable] : enumerate(buildables)) { - auto i = _i; - std::visit(overloaded { - [&](const BuiltPath::Opaque & bo) { - auto symlink = outLink; - if (i) symlink += fmt("-%d", i); - store2.addPermRoot(bo.path, absPath(symlink.string())); - }, - [&](const BuiltPath::Built & bfd) { - for (auto & output : bfd.outputs) { - auto symlink = outLink; - if (i) symlink += fmt("-%d", i); - if (output.first != "out") symlink += fmt("-%s", output.first); - store2.addPermRoot(output.second, absPath(symlink.string())); - } - }, - }, buildable.path.raw()); - } -} - struct CmdBuild : InstallablesCommand, MixDryRun, MixJSON, MixProfile { Path outLink = "result"; @@ -140,7 +117,7 @@ struct CmdBuild : InstallablesCommand, MixDryRun, MixJSON, MixProfile if (outLink != "") if (auto store2 = store.dynamic_pointer_cast()) - createOutLinks(outLink, buildables, *store2); + createOutLinks(outLink, toBuiltPaths(buildables), *store2); if (printOutputPaths) { stopProgressBar(); diff --git a/src/nix/copy.cc b/src/nix/copy.cc index 151d28277..399a6c0fd 100644 --- a/src/nix/copy.cc +++ b/src/nix/copy.cc @@ -1,11 +1,13 @@ #include "command.hh" #include "shared.hh" #include "store-api.hh" +#include "local-fs-store.hh" using namespace nix; -struct CmdCopy : virtual CopyCommand, virtual BuiltPathsCommand +struct CmdCopy : virtual CopyCommand, virtual BuiltPathsCommand, MixProfile { + std::optional outLink; CheckSigsFlag checkSigs = CheckSigs; SubstituteFlag substitute = NoSubstitute; @@ -13,6 +15,15 @@ struct CmdCopy : virtual CopyCommand, virtual BuiltPathsCommand CmdCopy() : BuiltPathsCommand(true) { + addFlag({ + .longName = "out-link", + .shortName = 'o', + .description = "Create symlinks prefixed with *path* to the top-level store paths fetched from the source store.", + .labels = {"path"}, + .handler = {&outLink}, + .completer = completePath + }); + addFlag({ .longName = "no-check-sigs", .description = "Do not require that paths are signed by trusted keys.", @@ -43,19 +54,28 @@ struct CmdCopy : virtual CopyCommand, virtual BuiltPathsCommand Category category() override { return catSecondary; } - void run(ref srcStore, BuiltPaths && paths) override + void run(ref srcStore, BuiltPaths && allPaths, BuiltPaths && rootPaths) override { auto dstStore = getDstStore(); RealisedPath::Set stuffToCopy; - for (auto & builtPath : paths) { + for (auto & builtPath : allPaths) { auto theseRealisations = builtPath.toRealisedPaths(*srcStore); stuffToCopy.insert(theseRealisations.begin(), theseRealisations.end()); } copyPaths( *srcStore, *dstStore, stuffToCopy, NoRepair, checkSigs, substitute); + + updateProfile(rootPaths); + + if (outLink) { + if (auto store2 = dstStore.dynamic_pointer_cast()) + createOutLinks(*outLink, rootPaths, *store2); + else + throw Error("'--out-link' is not supported for this Nix store"); + } } }; diff --git a/src/nix/copy.md b/src/nix/copy.md index 6ab7cdee3..813050fcb 100644 --- a/src/nix/copy.md +++ b/src/nix/copy.md @@ -55,6 +55,15 @@ R""( # nix copy --to /tmp/nix nixpkgs#hello --no-check-sigs ``` +* Update the NixOS system profile to point to a closure copied from a + remote machine: + + ```console + # nix copy --from ssh://server \ + --profile /nix/var/nix/profiles/system \ + /nix/store/r14v3km89zm3prwsa521fab5kgzvfbw4-nixos-system-foobar-24.05.20240925.759537f + ``` + # Description `nix copy` copies store path closures between two Nix stores. The diff --git a/src/nix/realisation.cc b/src/nix/realisation.cc index e1f231222..a386d98ea 100644 --- a/src/nix/realisation.cc +++ b/src/nix/realisation.cc @@ -36,7 +36,7 @@ struct CmdRealisationInfo : BuiltPathsCommand, MixJSON Category category() override { return catSecondary; } - void run(ref store, BuiltPaths && paths) override + void run(ref store, BuiltPaths && paths, BuiltPaths && rootPaths) override { experimentalFeatureSettings.require(Xp::CaDerivations); RealisedPath::Set realisations; diff --git a/tests/functional/zstd.sh b/tests/functional/zstd.sh index 450fb7d35..226d5eb68 100755 --- a/tests/functional/zstd.sh +++ b/tests/functional/zstd.sh @@ -18,7 +18,10 @@ HASH=$(nix hash path "$outPath") clearStore clearCacheCache -nix copy --from "$cacheURI" "$outPath" --no-check-sigs +nix copy --from "$cacheURI" "$outPath" --no-check-sigs --profile "$TEST_ROOT/profile" --out-link "$TEST_ROOT/result" + +[[ -e $TEST_ROOT/profile ]] +[[ -e $TEST_ROOT/result ]] if ls "$cacheDir/nar/"*.zst &> /dev/null; then echo "files do exist"