From 64e23d0a38f316a07cef0960d0ed74a450214283 Mon Sep 17 00:00:00 2001 From: Shea Levy Date: Sat, 8 Feb 2014 00:05:46 -0500 Subject: [PATCH] Add download-via-ssh substituter This substituter connects to a remote host, runs nix-store --serve there, and then forwards substituter commands on to the remote host and sends their results to the calling program. The ssh-substituter-hosts option can be specified as a list of hosts to try. This is an initial implementation and, while it works, it has some limitations: * Only the first host is used * There is no caching of query results (all queries are sent to the remote machine) * There is no informative output (such as progress bars) * Some failure modes may cause unhelpful error messages * There is no concept of trusted-ssh-substituter-hosts Signed-off-by: Shea Levy --- Makefile | 1 + src/download-via-ssh/download-via-ssh.cc | 129 +++++++++++++++++++++++ src/download-via-ssh/local.mk | 9 ++ src/libmain/shared.cc | 3 + src/libstore/globals.cc | 20 ++++ src/libstore/globals.hh | 6 ++ 6 files changed, 168 insertions(+) create mode 100644 src/download-via-ssh/download-via-ssh.cc create mode 100644 src/download-via-ssh/local.mk diff --git a/Makefile b/Makefile index 0ad6bb236..78d85ebc5 100644 --- a/Makefile +++ b/Makefile @@ -10,6 +10,7 @@ makefiles = \ src/nix-instantiate/local.mk \ src/nix-env/local.mk \ src/nix-daemon/local.mk \ + src/download-via-ssh/local.mk \ src/nix-log2xml/local.mk \ src/bsdiff-4.3/local.mk \ perl/local.mk \ diff --git a/src/download-via-ssh/download-via-ssh.cc b/src/download-via-ssh/download-via-ssh.cc new file mode 100644 index 000000000..7adb93e10 --- /dev/null +++ b/src/download-via-ssh/download-via-ssh.cc @@ -0,0 +1,129 @@ +#include "shared.hh" +#include "util.hh" +#include "serialise.hh" +#include "archive.hh" +#include "affinity.hh" +#include "globals.hh" + +#include +#include + +using namespace nix; +using std::pair; +using std::cout; +using std::endl; + +// !!! TODO: +// * Respect more than the first host +// * use a database +// * show progress + +static pair connect(string conn) { + Pipe to, from; + to.create(); + from.create(); + pid_t child = fork(); + switch (child) { + case -1: + throw SysError("unable to fork"); + case 0: + try { + restoreAffinity(); + if (dup2(to.readSide, STDIN_FILENO) == -1) + throw SysError("dupping stdin"); + if (dup2(from.writeSide, STDOUT_FILENO) == -1) + throw SysError("dupping stdout"); + execlp("ssh" + , "ssh" + , "-x" + , "-T" + , conn.c_str() + , "nix-store --serve" + , NULL); + throw SysError("executing ssh"); + } catch (std::exception & e) { + std::cerr << "error: " << e.what() << std::endl; + } + _exit(1); + } + // If child exits unexpectedly, we'll EPIPE. If we exit unexpectedly, child will + // So no need to keep track of it. + + return pair(to.writeSide.borrow(), from.readSide.borrow()); +} + +static void substitute(pair & pipes, Path storePath, Path destPath) { + writeString("substitute", pipes.first); + writeString(storePath, pipes.first); + pipes.first.flush(); + restorePath(destPath, pipes.second); + cout << endl; +} + +static void query(pair & pipes) { + using std::cin; + writeString("query", pipes.first); + for (string line; getline(cin, line);) { + Strings tokenized = tokenizeString(line); + string cmd = tokenized.front(); + writeString(cmd, pipes.first); + tokenized.pop_front(); + foreach (Strings::iterator, i, tokenized) + writeStrings(tokenized, pipes.first); + pipes.first.flush(); + if (cmd == "have") { + PathSet paths = readStrings(pipes.second); + foreach (PathSet::iterator, i, paths) + cout << *i << endl; + } else if (cmd == "info") { + for (Path path = readString(pipes.second); !path.empty(); path = readString(pipes.second)) { + cout << path << endl; + cout << readString(pipes.second) << endl; + PathSet references = readStrings(pipes.second); + cout << references.size() << endl; + foreach (PathSet::iterator, i, references) + cout << *i << endl; + cout << readLongLong(pipes.second) << endl; + cout << readLongLong(pipes.second) << endl; + } + } else + throw Error(format("Unknown substituter query `%1%'") % cmd); + cout << endl; + } + writeString("", pipes.first); +} + +void run(Strings args) +{ + if (args.empty()) + throw UsageError("download-via-ssh requires an argument"); + + if (settings.sshSubstituterHosts.empty()) + return; + + cout << endl; + + pair pipes = connect(settings.sshSubstituterHosts.front()); + + Strings::iterator i = args.begin(); + if (*i == "--query") + query(pipes); + else if (*i == "--substitute") + if (args.size() != 3) + throw UsageError("download-via-ssh: --substitute takes exactly two arguments"); + else { + Path storePath = *++i; + Path destPath = *++i; + substitute(pipes, storePath, destPath); + } + else + throw UsageError(format("download-via-ssh: unknown command `%1%'") % *i); +} + +void printHelp() +{ + std::cerr << "Usage: download-via-ssh --query|--substitute store-path dest-path" << std::endl; +} + + +string programId = "download-via-ssh"; diff --git a/src/download-via-ssh/local.mk b/src/download-via-ssh/local.mk new file mode 100644 index 000000000..92bf11594 --- /dev/null +++ b/src/download-via-ssh/local.mk @@ -0,0 +1,9 @@ +programs += download-via-ssh + +download-via-ssh_DIR := $(d) + +download-via-ssh_SOURCES := $(d)/download-via-ssh.cc + +download-via-ssh_INSTALL_DIR := $(libexecdir)/nix/substituters + +download-via-ssh_LIBS = libmain libstore libutil libformat diff --git a/src/libmain/shared.cc b/src/libmain/shared.cc index fb70cb076..30238c7fb 100644 --- a/src/libmain/shared.cc +++ b/src/libmain/shared.cc @@ -223,6 +223,9 @@ static void initAndRun(int argc, char * * argv) else remaining.push_back(arg); } + if (char *pack = getenv("_NIX_OPTIONS")) + settings.unpack(pack); + settings.update(); run(remaining); diff --git a/src/libstore/globals.cc b/src/libstore/globals.cc index 68add1982..c1ffc26fa 100644 --- a/src/libstore/globals.cc +++ b/src/libstore/globals.cc @@ -79,6 +79,7 @@ void Settings::processEnvironment() #endif substituters.push_back(nixLibexecDir + "/nix/substituters/download-using-manifests.pl"); substituters.push_back(nixLibexecDir + "/nix/substituters/download-from-binary-cache.pl"); + substituters.push_back(nixLibexecDir + "/nix/substituters/download-via-ssh"); } else substituters = tokenizeString(subs, ":"); } @@ -151,6 +152,7 @@ void Settings::update() get(gcKeepDerivations, "gc-keep-derivations"); get(autoOptimiseStore, "auto-optimise-store"); get(envKeepDerivations, "env-keep-derivations"); + get(sshSubstituterHosts, "ssh-substituter-hosts"); } @@ -182,6 +184,13 @@ void Settings::get(StringSet & res, const string & name) res.insert(ss.begin(), ss.end()); } +void Settings::get(Strings & res, const string & name) +{ + SettingsMap::iterator i = settings.find(name); + if (i == settings.end()) return; + res = tokenizeString(i->second); +} + template void Settings::get(N & res, const string & name) { @@ -206,6 +215,17 @@ string Settings::pack() } +void Settings::unpack(string pack) { + Strings lines = tokenizeString(pack, "\n"); + foreach (Strings::iterator, i, lines) { + string::size_type eq = i->find('='); + if (eq == string::npos) + throw Error("illegal option name/value"); + set(i->substr(0, eq), i->substr(eq + 1)); + } +} + + Settings::SettingsMap Settings::getOverrides() { return overrides; diff --git a/src/libstore/globals.hh b/src/libstore/globals.hh index 9300edbe9..5e7cfda9a 100644 --- a/src/libstore/globals.hh +++ b/src/libstore/globals.hh @@ -25,6 +25,8 @@ struct Settings { string pack(); + void unpack(string pack); + SettingsMap getOverrides(); /* The directory where we store sources and derived files. */ @@ -144,6 +146,9 @@ struct Settings { chroot. */ StringSet dirsInChroot; + /* Set of ssh connection strings for the ssh substituter */ + Strings sshSubstituterHosts; + /* Whether to impersonate a Linux 2.6 machine on newer kernels. */ bool impersonateLinux26; @@ -195,6 +200,7 @@ private: void get(string & res, const string & name); void get(bool & res, const string & name); void get(StringSet & res, const string & name); + void get(Strings & res, const string & name); template void get(N & res, const string & name); };