refactor(3p/nix): Build nix-daemon as a separate binary r/1569

Skips over all the monobinary stuff and moves to a separate binary for
nix-daemon.

This also replaces the flag parsing logic with absl::flags. This
causes a behaviour change for --help, which no longer tries to display
a man page but instead shows the actual command-line help.

Note: This binary no longer links to the Boehm GC.

Change-Id: Ib852e994b82f2d56e91262878c10650e656427a9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1622
Tested-by: BuildkiteCI
Reviewed-by: glittershark <grfn@gws.fyi>

1 files changed, 0 insertions, 143 deletions

diff --git a/third_party/nix/src/nix-daemon/nix-daemon-main.cc b/third_party/nix/src/nix-daemon/nix-daemon-main.cc
deleted file mode 100644
index e492c343b900..000000000000
--- a/third_party/nix/src/nix-daemon/nix-daemon-main.cc
+++ /dev/null
@@ -1,143 +0,0 @@
-#include <filesystem>
-
-#include <absl/strings/str_format.h>
-#include <fcntl.h>
-#include <glog/logging.h>
-#include <grpcpp/security/server_credentials.h>
-#include <grpcpp/server.h>
-#include <grpcpp/server_builder_impl.h>
-#include <sys/socket.h>
-#include <sys/un.h>
-
-#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<struct sockaddr*>(&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> 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