lix/src/download-via-ssh/download-via-ssh.cc
2015-07-20 01:16:16 +02:00

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#include "shared.hh"
#include "util.hh"
#include "serialise.hh"
#include "archive.hh"
#include "affinity.hh"
#include "globals.hh"
#include "serve-protocol.hh"
#include "worker-protocol.hh"
#include "store-api.hh"
#include <iostream>
#include <cstdlib>
#include <unistd.h>
using namespace nix;
// !!! TODO:
// * Respect more than the first host
// * use a database
// * show progress
static std::pair<FdSink, FdSource> connect(const string & conn)
{
Pipe to, from;
to.create();
from.create();
startProcess([&]() {
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");
});
// If child exits unexpectedly, we'll EPIPE or EOF early.
// If we exit unexpectedly, child will EPIPE or EOF early.
// So no need to keep track of it.
return std::pair<FdSink, FdSource>(to.writeSide.borrow(), from.readSide.borrow());
}
static void substitute(std::pair<FdSink, FdSource> & pipes, Path storePath, Path destPath)
{
pipes.first << cmdDumpStorePath << storePath;
pipes.first.flush();
restorePath(destPath, pipes.second);
std::cout << std::endl;
}
static void query(std::pair<FdSink, FdSource> & pipes)
{
for (string line; getline(std::cin, line);) {
Strings tokenized = tokenizeString<Strings>(line);
string cmd = tokenized.front();
tokenized.pop_front();
if (cmd == "have") {
pipes.first
<< cmdQueryValidPaths
<< 0 // don't lock
<< 0 // don't substitute
<< tokenized;
pipes.first.flush();
PathSet paths = readStrings<PathSet>(pipes.second);
for (auto & i : paths)
std::cout << i << std::endl;
} else if (cmd == "info") {
pipes.first << cmdQueryPathInfos << tokenized;
pipes.first.flush();
while (1) {
Path path = readString(pipes.second);
if (path.empty()) break;
assertStorePath(path);
std::cout << path << std::endl;
string deriver = readString(pipes.second);
if (!deriver.empty()) assertStorePath(deriver);
std::cout << deriver << std::endl;
PathSet references = readStorePaths<PathSet>(pipes.second);
std::cout << references.size() << std::endl;
for (auto & i : references)
std::cout << i << std::endl;
std::cout << readLongLong(pipes.second) << std::endl;
std::cout << readLongLong(pipes.second) << std::endl;
}
} else
throw Error(format("unknown substituter query %1%") % cmd);
std::cout << std::endl;
}
}
int main(int argc, char * * argv)
{
return handleExceptions(argv[0], [&]() {
if (argc < 2)
throw UsageError("download-via-ssh requires an argument");
initNix();
settings.update();
if (settings.sshSubstituterHosts.empty())
return;
std::cout << std::endl;
/* Pass on the location of the daemon client's SSH
authentication socket. */
string sshAuthSock = settings.get("ssh-auth-sock", string(""));
if (sshAuthSock != "") setenv("SSH_AUTH_SOCK", sshAuthSock.c_str(), 1);
string host = settings.sshSubstituterHosts.front();
std::pair<FdSink, FdSource> pipes = connect(host);
/* Exchange the greeting */
pipes.first << SERVE_MAGIC_1;
pipes.first.flush();
unsigned int magic = readInt(pipes.second);
if (magic != SERVE_MAGIC_2)
throw Error("protocol mismatch");
readInt(pipes.second); // Server version, unused for now
pipes.first << SERVE_PROTOCOL_VERSION;
pipes.first.flush();
string arg = argv[1];
if (arg == "--query")
query(pipes);
else if (arg == "--substitute") {
if (argc != 4)
throw UsageError("download-via-ssh: --substitute takes exactly two arguments");
Path storePath = argv[2];
Path destPath = argv[3];
printMsg(lvlError, format("downloading %1% via SSH from %2%...") % storePath % host);
substitute(pipes, storePath, destPath);
}
else
throw UsageError(format("download-via-ssh: unknown command %1%") % arg);
});
}