diff options
| -rw-r--r-- | third_party/nix/default.nix | 1 | ||||
| -rw-r--r-- | third_party/nix/src/nix-daemon/CMakeLists.txt | 3 | ||||
| -rw-r--r-- | third_party/nix/src/nix-daemon/nix-daemon.cc | 95 |
3 files changed, 85 insertions, 14 deletions
diff --git a/third_party/nix/default.nix b/third_party/nix/default.nix index ab54206492..3403b1a14c 100644 --- a/third_party/nix/default.nix +++ b/third_party/nix/default.nix @@ -61,6 +61,7 @@ in lib.fix (self: pkgs.llvmPackages.libcxxStdenv.mkDerivation { grpc libseccomp libsodium + systemd.lib.dev openssl protobuf sqlite diff --git a/third_party/nix/src/nix-daemon/CMakeLists.txt b/third_party/nix/src/nix-daemon/CMakeLists.txt index 27a4a1254e..63125a9b26 100644 --- a/third_party/nix/src/nix-daemon/CMakeLists.txt +++ b/third_party/nix/src/nix-daemon/CMakeLists.txt @@ -8,6 +8,8 @@ add_executable(nix-daemon) include_directories(${PROJECT_BINARY_DIR}) # for config.h set_property(TARGET nix-daemon PROPERTY CXX_STANDARD 17) +pkg_check_modules(systemd REQUIRED) + target_sources(nix-daemon PRIVATE nix-daemon-proto.hh @@ -21,6 +23,7 @@ target_link_libraries(nix-daemon nixmain absl::flags absl::flags_parse + systemd ) install(TARGETS nix-daemon DESTINATION bin) diff --git a/third_party/nix/src/nix-daemon/nix-daemon.cc b/third_party/nix/src/nix-daemon/nix-daemon.cc index f4128fa4b2..fd7a553e20 100644 --- a/third_party/nix/src/nix-daemon/nix-daemon.cc +++ b/third_party/nix/src/nix-daemon/nix-daemon.cc @@ -8,9 +8,11 @@ #include <glog/logging.h> #include <grpcpp/security/server_credentials.h> #include <grpcpp/server.h> -#include <grpcpp/server_builder_impl.h> +#include <grpcpp/server_builder.h> +#include <grpcpp/server_posix.h> #include <sys/socket.h> #include <sys/un.h> +#include <systemd/sd-daemon.h> #include "libmain/shared.hh" // TODO(tazjin): can this be removed? #include "libstore/globals.hh" @@ -27,6 +29,8 @@ namespace nix::daemon { using grpc::Server; using grpc_impl::ServerBuilder; +namespace { + // TODO(grfn): There has to be a better way to do this - this was ported // verbatim from the old daemon implementation without much critical evaluation. static int ForwardToSocket(nix::Path socket_path) { @@ -86,35 +90,98 @@ static int ForwardToSocket(nix::Path socket_path) { } } +void SetNonBlocking(int fd) { + int flags = fcntl(fd, F_GETFL); // NOLINT + PCHECK(flags != 0) << "Error getting socket flags"; + PCHECK(fcntl( // NOLINT + fd, F_SETFL, flags | O_NONBLOCK) == 0) + << "Could not set socket flags"; +} + +} // namespace + int RunServer() { Store::Params params; params["path-info-cache-size"] = "0"; auto store = openStore(settings.storeUri, params); auto worker = NewWorkerService(*store); - - std::filesystem::path socket_path(settings.nixDaemonSocketFile); - std::filesystem::create_directories(socket_path.parent_path()); - auto socket_addr = absl::StrFormat("unix://%s", socket_path); - ServerBuilder builder; - builder.AddListeningPort(socket_addr, grpc::InsecureServerCredentials()); builder.RegisterService(worker); + auto n_fds = sd_listen_fds(0); + + if (n_fds > 1) { + LOG(FATAL) << "Too many file descriptors (" << n_fds + << ") received from systemd socket activation"; + } + + std::filesystem::path socket_path; + + if (n_fds == 0) { + socket_path = settings.nixDaemonSocketFile; + std::filesystem::create_directories(socket_path.parent_path()); + auto socket_addr = absl::StrFormat("unix://%s", socket_path); + builder.AddListeningPort(socket_addr, grpc::InsecureServerCredentials()); + } + std::unique_ptr<Server> server(builder.BuildAndStart()); - if (server) { - LOG(INFO) << "Nix daemon listening at " << socket_addr; - server->Wait(); - return 0; - } else { + + if (!server) { + LOG(FATAL) << "Error building server"; return 1; } + + // We have been systemd socket-activated - instead of asking grpc to make the + // socket path for us, start our own accept loop and pass file descriptors to + // grpc. + // + // This approach was *somewhat* adapted from + // https://gist.github.com/yorickvP/8d523a4df2b10c5812fa7789e82b7c1b - at some + // point we'd like gRPC to do it for us, though - see + // https://github.com/grpc/grpc/issues/19133 + if (n_fds == 1) { + int socket_fd = SD_LISTEN_FDS_START; + // Only used for logging + socket_path = readLink(absl::StrFormat("/proc/self/fd/%d", socket_fd)); + + PCHECK(sd_notify(0, "READY=1") == 0) << "Error notifying systemd"; + for (;;) { + try { + struct sockaddr_un remote_addr {}; + socklen_t remote_addr_len = sizeof(remote_addr); + int remote_fd = + accept(socket_fd, + reinterpret_cast<struct sockaddr*>(&remote_addr), // NOLINT + &remote_addr_len); + checkInterrupt(); + if (!remote_fd) { + if (errno == EINTR) { + continue; + } + PCHECK(false) << "error accepting connection"; + } + + LOG(INFO) << "Accepted remote connection on fd " << remote_fd; + SetNonBlocking(remote_fd); + grpc::AddInsecureChannelFromFd(server.get(), remote_fd); + } catch (Interrupted& e) { + return -1; + } catch (Error& e) { + LOG(ERROR) << "error processing connection: " << e.msg(); + } + } + } + + LOG(INFO) << "Nix daemon listening at " << socket_path; + server->Wait(); + return 0; } } // namespace nix::daemon -int main(int argc, char** argv) { +int main(int argc, char** argv) { // NOLINT FLAGS_logtostderr = true; - google::InitGoogleLogging(argv[0]); + google::InitGoogleLogging(argv[0]); // NOLINT absl::SetFlagsUsageConfig({.version_string = [] { return nix::nixVersion; }}); absl::ParseCommandLine(argc, argv); |