From 7c5596734f65b30b250ea73a423b40a4ce513fdf Mon Sep 17 00:00:00 2001 From: regnat Date: Thu, 11 Jul 2019 20:23:03 +0200 Subject: [PATCH 1/2] Add a post-build-hook Passing `--post-build-hook /foo/bar` to a nix-* command will cause `/foo/bar` to be executed after each build with the following environment variables set: DRV_PATH=/nix/store/drv-that-has-been-built.drv OUT_PATHS=/nix/store/...build /nix/store/...build-bin /nix/store/...build-dev This can be useful in particular to upload all the builded artifacts to the cache (including the ones that don't appear in the runtime closure of the final derivation or are built because of IFD). This new feature prints the stderr/stdout output to the `nix-build` and `nix build` client, and the output is printed in a Nix 2 compatible format: [nix]$ ./inst/bin/nix-build ./test.nix these derivations will be built: /nix/store/ishzj9ni17xq4hgrjvlyjkfvm00b0ch9-my-example-derivation.drv building '/nix/store/ishzj9ni17xq4hgrjvlyjkfvm00b0ch9-my-example-derivation.drv'... hello! bye! running post-build-hook '/home/grahamc/projects/github.com/NixOS/nix/post-hook.sh'... post-build-hook: + sleep 1 post-build-hook: + echo 'Signing paths' /nix/store/qr213vjmibrqwnyp5fw678y7whbkqyny-my-example-derivation post-build-hook: Signing paths /nix/store/qr213vjmibrqwnyp5fw678y7whbkqyny-my-example-derivation post-build-hook: + sleep 1 post-build-hook: + echo 'Uploading paths' /nix/store/qr213vjmibrqwnyp5fw678y7whbkqyny-my-example-derivation post-build-hook: Uploading paths /nix/store/qr213vjmibrqwnyp5fw678y7whbkqyny-my-example-derivation post-build-hook: + sleep 1 post-build-hook: + printf 'very important stuff' /nix/store/qr213vjmibrqwnyp5fw678y7whbkqyny-my-example-derivation [nix-shell:~/projects/github.com/NixOS/nix]$ ./inst/bin/nix build -L -f ./test.nix my-example-derivation> hello! my-example-derivation> bye! my-example-derivation (post)> + sleep 1 my-example-derivation (post)> + echo 'Signing paths' /nix/store/c263gzj2kb2609mz8wrbmh53l14wzmfs-my-example-derivation my-example-derivation (post)> Signing paths /nix/store/c263gzj2kb2609mz8wrbmh53l14wzmfs-my-example-derivation my-example-derivation (post)> + sleep 1 my-example-derivation (post)> + echo 'Uploading paths' /nix/store/c263gzj2kb2609mz8wrbmh53l14wzmfs-my-example-derivation my-example-derivation (post)> Uploading paths /nix/store/c263gzj2kb2609mz8wrbmh53l14wzmfs-my-example-derivation my-example-derivation (post)> + sleep 1 my-example-derivation (post)> + printf 'very important stuff' [1 built, 0.0 MiB DL] Co-authored-by: Graham Christensen Co-authored-by: Eelco Dolstra --- .../advanced-topics/advanced-topics.xml | 1 + .../advanced-topics/post-build-hook.xml | 157 ++++++++++++++++++ doc/manual/command-ref/conf-file.xml | 55 ++++++ src/libstore/build.cc | 55 ++++++ src/libstore/globals.hh | 3 + src/libutil/logging.hh | 2 + src/libutil/util.cc | 23 ++- src/libutil/util.hh | 2 + src/nix/progress-bar.cc | 16 +- tests/dependencies.nix | 1 + tests/local.mk | 3 +- tests/post-hook.sh | 15 ++ tests/push_to_store.sh | 4 + 13 files changed, 333 insertions(+), 4 deletions(-) create mode 100644 doc/manual/advanced-topics/post-build-hook.xml create mode 100644 tests/post-hook.sh create mode 100755 tests/push_to_store.sh diff --git a/doc/manual/advanced-topics/advanced-topics.xml b/doc/manual/advanced-topics/advanced-topics.xml index c304367a..1b8841ad 100644 --- a/doc/manual/advanced-topics/advanced-topics.xml +++ b/doc/manual/advanced-topics/advanced-topics.xml @@ -8,5 +8,6 @@ + diff --git a/doc/manual/advanced-topics/post-build-hook.xml b/doc/manual/advanced-topics/post-build-hook.xml new file mode 100644 index 00000000..4335b308 --- /dev/null +++ b/doc/manual/advanced-topics/post-build-hook.xml @@ -0,0 +1,157 @@ + + +Using the <xref linkend="conf-post-build-hook" /> +Uploading to an S3-compatible binary cache after each build + + +
+ Implementation Caveats + Here we use the post-build hook to upload to a binary cache. + This is a simple and working example, but it is not suitable for all + use cases. + + The post build hook program runs after each executed build, + and blocks the build loop. The build loop exits if the hook program + fails. + + Concretely, this implementation will make Nix slow or unusable + when the internet is slow or unreliable. + + A more advanced implementation might pass the store paths to a + user-supplied daemon or queue for processing the store paths outside + of the build loop. +
+ +
+ Prerequisites + + + This tutorial assumes you have configured an S3-compatible binary cache + according to the instructions at + , and + that the root user's default AWS profile can + upload to the bucket. + +
+ +
+ Set up a Signing Key + Use nix-store --generate-binary-cache-key to + create our public and private signing keys. We will sign paths + with the private key, and distribute the public key for verifying + the authenticity of the paths. + + +# nix-store --generate-binary-cache-key example-nix-cache-1 /etc/nix/key.private /etc/nix/key.public +# cat /etc/nix/key.public +example-nix-cache-1:1/cKDz3QCCOmwcztD2eV6Coggp6rqc9DGjWv7C0G+rM= + + +Then, add the public key and the cache URL to your +nix.conf's +and like: + + +substituters = https://cache.nixos.org/ s3://example-nix-cache +trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= example-nix-cache-1:1/cKDz3QCCOmwcztD2eV6Coggp6rqc9DGjWv7C0G+rM= + + +we will restart the Nix daemon a later step. +
+ +
+ Implementing the build hook + Write the following script to + /etc/nix/upload-to-cache.sh: + + + +#!/bin/sh + +set -eu + +echo "Signing paths" $OUT_PATHS +nix sign-paths --key-file /etc/nix/key.private $OUT_PATHS +echo "Uploading paths" $OUT_PATHS +exec nix copy --to 's3://example-nix-cache' $OUT_PATHS + + + + Should <literal>$OUT_PATHS</literal> be quoted? + + The $OUT_PATHS variable is a space-separated + list of Nix store paths. In this case, we expect and want the + shell to perform word splitting to make each output path its + own argument to nix sign-paths. Nix guarantees + the paths will only contain characters which are safe for word + splitting, and free of any globs. + + + + Then make sure the hook program is executable by the root user: + +# chmod +x /etc/nix/upload-to-cache.sh + +
+ +
+ Updating Nix Configuration + + Edit /etc/nix/nix.conf to run our hook, + by adding the following configuration snippet at the end: + + +post-build-hook = /etc/nix/upload-to-cache.sh + + +Then, restart the nix-daemon. +
+ +
+ Testing + + Build any derivation, for example: + + +$ nix-build -E '(import <nixpkgs> {}).writeText "example" (builtins.toString builtins.currentTime)' +these derivations will be built: + /nix/store/s4pnfbkalzy5qz57qs6yybna8wylkig6-example.drv +building '/nix/store/s4pnfbkalzy5qz57qs6yybna8wylkig6-example.drv'... +running post-build-hook '/home/grahamc/projects/github.com/NixOS/nix/post-hook.sh'... +post-build-hook: Signing paths /nix/store/ibcyipq5gf91838ldx40mjsp0b8w9n18-example +post-build-hook: Uploading paths /nix/store/ibcyipq5gf91838ldx40mjsp0b8w9n18-example +/nix/store/ibcyipq5gf91838ldx40mjsp0b8w9n18-example + + + Then delete the path from the store, and try substituting it from the binary cache: + +$ rm ./result +$ nix-store --delete /nix/store/ibcyipq5gf91838ldx40mjsp0b8w9n18-example + + +Now, copy the path back from the cache: + +$ nix store --realize /nix/store/ibcyipq5gf91838ldx40mjsp0b8w9n18-example +copying path '/nix/store/m8bmqwrch6l3h8s0k3d673xpmipcdpsa-example from 's3://example-nix-cache'... +warning: you did not specify '--add-root'; the result might be removed by the garbage collector +/nix/store/m8bmqwrch6l3h8s0k3d673xpmipcdpsa-example + +
+
+ Conclusion + + We now have a Nix installation configured to automatically sign and + upload every local build to a remote binary cache. + + + + Before deploying this to production, be sure to consider the + implementation caveats in . + +
+ diff --git a/doc/manual/command-ref/conf-file.xml b/doc/manual/command-ref/conf-file.xml index 09aad2e0..d2c9c750 100644 --- a/doc/manual/command-ref/conf-file.xml +++ b/doc/manual/command-ref/conf-file.xml @@ -656,6 +656,61 @@ password my-password + + post-build-hook + + Optional. The path to a program to execute after each build. + + This option is only settable in the global + nix.conf, or on the command line by trusted + users. + + When using the nix-daemon, the daemon executes the hook as + root. If the nix-daemon is not involved, the + hook runs as the user executing the nix-build. + + + The hook executes after an evaluation-time build. + The hook does not execute on substituted paths. + The hook's output always goes to the user's terminal. + If the hook fails, the build succeeds but no further builds execute. + + + The program executes with no arguments. The program's environment + contains the following environment variables: + + + + DRV_PATH + + The derivation for the built paths. + Example: + /nix/store/5nihn1a7pa8b25l9zafqaqibznlvvp3f-bash-4.4-p23.drv + + + + + + OUT_PATHS + + Output paths of the built derivation, separated by a space ( ) character. + Example: + /nix/store/zf5lbh336mnzf1nlswdn11g4n2m8zh3g-bash-4.4-p23-dev + /nix/store/rjxwxwv1fpn9wa2x5ssk5phzwlcv4mna-bash-4.4-p23-doc + /nix/store/6bqvbzjkcp9695dq0dpl5y43nvy37pq1-bash-4.4-p23-info + /nix/store/r7fng3kk3vlpdlh2idnrbn37vh4imlj2-bash-4.4-p23-man + /nix/store/xfghy8ixrhz3kyy6p724iv3cxji088dx-bash-4.4-p23. + + + + + + See for an example + implementation. + + + + repeat How many times to repeat builds to check whether diff --git a/src/libstore/build.cc b/src/libstore/build.cc index cf6428e1..7494eec4 100644 --- a/src/libstore/build.cc +++ b/src/libstore/build.cc @@ -1629,6 +1629,61 @@ void DerivationGoal::buildDone() being valid. */ registerOutputs(); + if (settings.postBuildHook != "") { + Activity act(*logger, lvlInfo, actPostBuildHook, + fmt("running post-build-hook '%s'", settings.postBuildHook), + Logger::Fields{drvPath}); + PushActivity pact(act.id); + auto outputPaths = drv->outputPaths(); + std::map hookEnvironment = getEnv(); + + hookEnvironment.emplace("DRV_PATH", drvPath); + hookEnvironment.emplace("OUT_PATHS", chomp(concatStringsSep(" ", outputPaths))); + + RunOptions opts(settings.postBuildHook, {}); + opts.environment = hookEnvironment; + + struct LogSink : Sink { + Activity & act; + std::string currentLine; + + LogSink(Activity & act) : act(act) { } + + void operator() (const unsigned char * data, size_t len) override { + for (size_t i = 0; i < len; i++) { + auto c = data[i]; + + if (c == '\n') { + flushLine(); + } else { + currentLine += c; + } + } + } + + void flushLine() { + if (settings.verboseBuild) { + printError("post-build-hook: " + currentLine); + } else { + act.result(resPostBuildLogLine, currentLine); + } + currentLine.clear(); + } + + ~LogSink() { + if (currentLine != "") { + currentLine += '\n'; + flushLine(); + } + } + }; + LogSink sink(act); + + opts.standardOut = &sink; + opts.mergeStderrToStdout = true; + runProgram2(opts); + } + if (buildMode == bmCheck) { done(BuildResult::Built); return; diff --git a/src/libstore/globals.hh b/src/libstore/globals.hh index 0af8215d..7dea6892 100644 --- a/src/libstore/globals.hh +++ b/src/libstore/globals.hh @@ -315,6 +315,9 @@ public: "pre-build-hook", "A program to run just before a build to set derivation-specific build settings."}; + Setting postBuildHook{this, "", "post-build-hook", + "A program to run just after each succesful build."}; + Setting netrcFile{this, fmt("%s/%s", nixConfDir, "netrc"), "netrc-file", "Path to the netrc file used to obtain usernames/passwords for downloads."}; diff --git a/src/libutil/logging.hh b/src/libutil/logging.hh index 5f221944..5df03da7 100644 --- a/src/libutil/logging.hh +++ b/src/libutil/logging.hh @@ -26,6 +26,7 @@ typedef enum { actVerifyPaths = 107, actSubstitute = 108, actQueryPathInfo = 109, + actPostBuildHook = 110, } ActivityType; typedef enum { @@ -36,6 +37,7 @@ typedef enum { resSetPhase = 104, resProgress = 105, resSetExpected = 106, + resPostBuildLogLine = 107, } ResultType; typedef uint64_t ActivityId; diff --git a/src/libutil/util.cc b/src/libutil/util.cc index 17aee2d5..44fa7248 100644 --- a/src/libutil/util.cc +++ b/src/libutil/util.cc @@ -84,6 +84,15 @@ void clearEnv() unsetenv(name.first.c_str()); } +void replaceEnv(std::map newEnv) +{ + clearEnv(); + for (auto newEnvVar : newEnv) + { + setenv(newEnvVar.first.c_str(), newEnvVar.second.c_str(), 1); + } +} + Path absPath(Path path, Path dir) { @@ -1019,10 +1028,22 @@ void runProgram2(const RunOptions & options) if (options.standardOut) out.create(); if (source) in.create(); + ProcessOptions processOptions; + // vfork implies that the environment of the main process and the fork will + // be shared (technically this is undefined, but in practice that's the + // case), so we can't use it if we alter the environment + if (options.environment) + processOptions.allowVfork = false; + /* Fork. */ Pid pid = startProcess([&]() { + if (options.environment) + replaceEnv(*options.environment); if (options.standardOut && dup2(out.writeSide.get(), STDOUT_FILENO) == -1) throw SysError("dupping stdout"); + if (options.mergeStderrToStdout) + if (dup2(STDOUT_FILENO, STDERR_FILENO) == -1) + throw SysError("cannot dup stdout into stderr"); if (source && dup2(in.readSide.get(), STDIN_FILENO) == -1) throw SysError("dupping stdin"); @@ -1047,7 +1068,7 @@ void runProgram2(const RunOptions & options) execv(options.program.c_str(), stringsToCharPtrs(args_).data()); throw SysError("executing '%1%'", options.program); - }); + }, processOptions); out.writeSide = -1; diff --git a/src/libutil/util.hh b/src/libutil/util.hh index fce3cab8..b538a0b4 100644 --- a/src/libutil/util.hh +++ b/src/libutil/util.hh @@ -270,12 +270,14 @@ struct RunOptions std::optional uid; std::optional gid; std::optional chdir; + std::optional> environment; Path program; bool searchPath = true; Strings args; std::optional input; Source * standardIn = nullptr; Sink * standardOut = nullptr; + bool mergeStderrToStdout = false; bool _killStderr = false; RunOptions(const Path & program, const Strings & args) diff --git a/src/nix/progress-bar.cc b/src/nix/progress-bar.cc index b1c1d87d..c0bcfb0c 100644 --- a/src/nix/progress-bar.cc +++ b/src/nix/progress-bar.cc @@ -170,6 +170,14 @@ public: name, sub); } + if (type == actPostBuildHook) { + auto name = storePathToName(getS(fields, 0)); + if (hasSuffix(name, ".drv")) + name.resize(name.size() - 4); + i->s = fmt("post-build " ANSI_BOLD "%s" ANSI_NORMAL, name); + i->name = DrvName(name).name; + } + if (type == actQueryPathInfo) { auto name = storePathToName(getS(fields, 0)); i->s = fmt("querying " ANSI_BOLD "%s" ANSI_NORMAL " on %s", name, getS(fields, 1)); @@ -228,14 +236,18 @@ public: update(*state); } - else if (type == resBuildLogLine) { + else if (type == resBuildLogLine || type == resPostBuildLogLine) { auto lastLine = trim(getS(fields, 0)); if (!lastLine.empty()) { auto i = state->its.find(act); assert(i != state->its.end()); ActInfo info = *i->second; if (printBuildLogs) { - log(*state, lvlInfo, ANSI_FAINT + info.name.value_or("unnamed") + "> " + ANSI_NORMAL + lastLine); + auto suffix = "> "; + if (type == resPostBuildLogLine) { + suffix = " (post)> "; + } + log(*state, lvlInfo, ANSI_FAINT + info.name.value_or("unnamed") + suffix + ANSI_NORMAL + lastLine); } else { state->activities.erase(i->second); info.lastLine = lastLine; diff --git a/tests/dependencies.nix b/tests/dependencies.nix index 687237ad..eca4b296 100644 --- a/tests/dependencies.nix +++ b/tests/dependencies.nix @@ -17,6 +17,7 @@ let { builder = ./dependencies.builder0.sh + "/FOOBAR/../."; input1 = input1 + "/."; input2 = "${input2}/."; + input1_drv = input1; meta.description = "Random test package"; }; diff --git a/tests/local.mk b/tests/local.mk index 1ff68348..8daaa859 100644 --- a/tests/local.mk +++ b/tests/local.mk @@ -26,7 +26,8 @@ nix_tests = \ check.sh \ plugins.sh \ search.sh \ - nix-copy-ssh.sh + nix-copy-ssh.sh \ + post-hook.sh # parallel.sh install-tests += $(foreach x, $(nix_tests), tests/$(x)) diff --git a/tests/post-hook.sh b/tests/post-hook.sh new file mode 100644 index 00000000..3f82d0c5 --- /dev/null +++ b/tests/post-hook.sh @@ -0,0 +1,15 @@ +source common.sh + +clearStore + +export REMOTE_STORE=$TEST_ROOT/remote_store + +# Build the dependencies and push them to the remote store +nix-build dependencies.nix --post-build-hook $PWD/push_to_store.sh + +clearStore + +# Ensure that we the remote store contains both the runtime and buildtime +# closure of what we've just built +nix copy --from "$REMOTE_STORE" --no-require-sigs -f dependencies.nix +nix copy --from "$REMOTE_STORE" --no-require-sigs -f dependencies.nix input1_drv diff --git a/tests/push_to_store.sh b/tests/push_to_store.sh new file mode 100755 index 00000000..d97eb095 --- /dev/null +++ b/tests/push_to_store.sh @@ -0,0 +1,4 @@ +#!/bin/sh + +echo Pushing "$@" to "$REMOTE_STORE" +echo -n "$OUT_PATHS" | xargs -d: nix copy --to "$REMOTE_STORE" --no-require-sigs From 363a2f68261af73aefe4edead9c0526030751a27 Mon Sep 17 00:00:00 2001 From: Graham Christensen Date: Tue, 6 Aug 2019 14:26:43 -0400 Subject: [PATCH 2/2] post-build-hook: docs fixup --- doc/manual/advanced-topics/post-build-hook.xml | 7 +++++-- doc/manual/command-ref/conf-file.xml | 3 ++- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/doc/manual/advanced-topics/post-build-hook.xml b/doc/manual/advanced-topics/post-build-hook.xml index 4335b308..3dc43ee7 100644 --- a/doc/manual/advanced-topics/post-build-hook.xml +++ b/doc/manual/advanced-topics/post-build-hook.xml @@ -74,6 +74,8 @@ trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDS #!/bin/sh set -eu +set -f # disable globbing +export IFS=' ' echo "Signing paths" $OUT_PATHS nix sign-paths --key-file /etc/nix/key.private $OUT_PATHS @@ -88,8 +90,9 @@ exec nix copy --to 's3://example-nix-cache' $OUT_PATHS list of Nix store paths. In this case, we expect and want the shell to perform word splitting to make each output path its own argument to nix sign-paths. Nix guarantees - the paths will only contain characters which are safe for word - splitting, and free of any globs. + the paths will not contain any spaces, however a store path + might contain glob characters. The set -f + disables globbing in the shell. diff --git a/doc/manual/command-ref/conf-file.xml b/doc/manual/command-ref/conf-file.xml index d2c9c750..e818a74c 100644 --- a/doc/manual/command-ref/conf-file.xml +++ b/doc/manual/command-ref/conf-file.xml @@ -674,6 +674,7 @@ password my-password The hook does not execute on substituted paths. The hook's output always goes to the user's terminal. If the hook fails, the build succeeds but no further builds execute. + The hook executes synchronously, and blocks other builds from progressing while it runs. The program executes with no arguments. The program's environment @@ -693,7 +694,7 @@ password my-password OUT_PATHS - Output paths of the built derivation, separated by a space ( ) character. + Output paths of the built derivation, separated by a space character. Example: /nix/store/zf5lbh336mnzf1nlswdn11g4n2m8zh3g-bash-4.4-p23-dev /nix/store/rjxwxwv1fpn9wa2x5ssk5phzwlcv4mna-bash-4.4-p23-doc