From dcaba9de64354fa699ee6b292efbedfb984582db Mon Sep 17 00:00:00 2001 From: Griffin Smith Date: Thu, 23 Jul 2020 12:35:52 -0400 Subject: feat(3p/nix): Add main function for grpc daemon Implement the main function for the new, proto-based nix daemon. This mostly replicates the behavior of the previous nix daemon - it starts a grpc server listening on the same nix socket path and supports the same set of options - with the exception of --stdio, which has been renamed to --pipe and documented in the man page. Change-Id: Ib729283c1d5d35c0e1b0a968bc1f052f5527f2d7 Reviewed-on: https://cl.tvl.fyi/c/depot/+/1356 Tested-by: BuildkiteCI Reviewed-by: tazjin Reviewed-by: kanepyork --- third_party/nix/src/nix-daemon/nix-daemon-main.cc | 143 ++++++++++++++++++++++ 1 file changed, 143 insertions(+) create mode 100644 third_party/nix/src/nix-daemon/nix-daemon-main.cc (limited to 'third_party/nix/src/nix-daemon/nix-daemon-main.cc') diff --git a/third_party/nix/src/nix-daemon/nix-daemon-main.cc b/third_party/nix/src/nix-daemon/nix-daemon-main.cc new file mode 100644 index 000000000000..e492c343b900 --- /dev/null +++ b/third_party/nix/src/nix-daemon/nix-daemon-main.cc @@ -0,0 +1,143 @@ +#include + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "libmain/shared.hh" +#include "libstore/globals.hh" +#include "libstore/store-api.hh" +#include "libutil/util.hh" +#include "nix-daemon-proto.hh" +#include "nix-daemon/nix-daemon-proto.hh" +#include "nix/legacy.hh" + +namespace nix::daemon { + +using grpc::Server; +using grpc_impl::ServerBuilder; + +// 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) { + // Forward on this connection to the real daemon + int sockfd = socket(PF_UNIX, SOCK_STREAM, 0); + if (sockfd == -1) { + throw SysError("creating Unix domain socket"); + } + + auto socketDir = dirOf(socket_path); + if (chdir(socketDir.c_str()) == -1) { + throw SysError(format("changing to socket directory '%1%'") % socketDir); + } + + auto socketName = baseNameOf(socket_path); + auto addr = sockaddr_un{}; + addr.sun_family = AF_UNIX; + if (socketName.size() + 1 >= sizeof(addr.sun_path)) { + throw Error(format("socket name %1% is too long") % socketName); + } + strncpy(addr.sun_path, socketName.c_str(), sizeof(addr.sun_family)); + + if (connect(sockfd, reinterpret_cast(&addr), + sizeof(addr)) == -1) { + throw SysError(format("cannot connect to daemon at %1%") % socket_path); + } + + auto nfds = (sockfd > STDIN_FILENO ? sockfd : STDIN_FILENO) + 1; + while (true) { + fd_set fds; + FD_ZERO(&fds); + FD_SET(sockfd, &fds); + FD_SET(STDIN_FILENO, &fds); + if (select(nfds, &fds, nullptr, nullptr, nullptr) == -1) { + throw SysError("waiting for data from client or server"); + } + if (FD_ISSET(sockfd, &fds)) { + auto res = splice(sockfd, nullptr, STDOUT_FILENO, nullptr, SSIZE_MAX, + SPLICE_F_MOVE); + if (res == -1) { + throw SysError("splicing data from daemon socket to stdout"); + } + if (res == 0) { + throw EndOfFile("unexpected EOF from daemon socket"); + } + } + if (FD_ISSET(STDIN_FILENO, &fds)) { + auto res = splice(STDIN_FILENO, nullptr, sockfd, nullptr, SSIZE_MAX, + SPLICE_F_MOVE); + if (res == -1) { + throw SysError("splicing data from stdin to daemon socket"); + } + if (res == 0) { + return 0; + } + } + } +} + +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); + + std::unique_ptr server(builder.BuildAndStart()); + if (server) { + LOG(INFO) << "Nix daemon listening at " << socket_addr; + server->Wait(); + return 0; + } else { + return 1; + } +} + +static int main_(int argc, char** argv) { + auto pipe = false; + + // TODO(grfn): Replace with absl::flags + parseCmdLine(argc, argv, + [&](Strings::iterator& arg, const Strings::iterator& end) { + if (*arg == "--help") { + showManPage("nix-daemon"); + } else if (*arg == "--version") { + printVersion("nix-daemon"); + } else if (*arg == "--pipe") { + // Causes the daemon to forward stdin and stdout to and from + // the actual daemon socket + pipe = true; + } else { + return false; + } + return true; + }); + + if (pipe) { + if (getStoreType() == tDaemon) { + return ForwardToSocket(settings.nixDaemonSocketFile); + } else { + // TODO(grfn): Need to launch a server on stdin here - upstream calls + // processConnection(true, "root", 0); + throw "Not implemented"; + } + } + return RunServer(); +} + +// TODO(grfn): Replace this with something less magical +static RegisterLegacyCommand s1("nix-daemon", main_); + +} // namespace nix::daemon -- cgit 1.4.1