lix/src/libstore/legacy-ssh-store.cc
Eelco Dolstra f186000367
Add some noexcepts
This is to assert that callback functions should never throw (since
the context in which they're called may not be able to handle the
exception).
2019-09-03 13:45:35 +02:00

294 lines
8.8 KiB
C++

#include "archive.hh"
#include "pool.hh"
#include "remote-store.hh"
#include "serve-protocol.hh"
#include "store-api.hh"
#include "worker-protocol.hh"
#include "ssh.hh"
#include "derivations.hh"
namespace nix {
static std::string uriScheme = "ssh://";
struct LegacySSHStore : public Store
{
const Setting<int> maxConnections{this, 1, "max-connections", "maximum number of concurrent SSH connections"};
const Setting<Path> sshKey{this, "", "ssh-key", "path to an SSH private key"};
const Setting<bool> compress{this, false, "compress", "whether to compress the connection"};
const Setting<Path> remoteProgram{this, "nix-store", "remote-program", "path to the nix-store executable on the remote system"};
const Setting<std::string> remoteStore{this, "", "remote-store", "URI of the store on the remote system"};
// Hack for getting remote build log output.
const Setting<int> logFD{this, -1, "log-fd", "file descriptor to which SSH's stderr is connected"};
struct Connection
{
std::unique_ptr<SSHMaster::Connection> sshConn;
FdSink to;
FdSource from;
int remoteVersion;
bool good = true;
};
std::string host;
ref<Pool<Connection>> connections;
SSHMaster master;
LegacySSHStore(const string & host, const Params & params)
: Store(params)
, host(host)
, connections(make_ref<Pool<Connection>>(
std::max(1, (int) maxConnections),
[this]() { return openConnection(); },
[](const ref<Connection> & r) { return r->good; }
))
, master(
host,
sshKey,
// Use SSH master only if using more than 1 connection.
connections->capacity() > 1,
compress,
logFD)
{
}
ref<Connection> openConnection()
{
auto conn = make_ref<Connection>();
conn->sshConn = master.startCommand(
fmt("%s --serve --write", remoteProgram)
+ (remoteStore.get() == "" ? "" : " --store " + shellEscape(remoteStore.get())));
conn->to = FdSink(conn->sshConn->in.get());
conn->from = FdSource(conn->sshConn->out.get());
try {
conn->to << SERVE_MAGIC_1 << SERVE_PROTOCOL_VERSION;
conn->to.flush();
unsigned int magic = readInt(conn->from);
if (magic != SERVE_MAGIC_2)
throw Error("protocol mismatch with 'nix-store --serve' on '%s'", host);
conn->remoteVersion = readInt(conn->from);
if (GET_PROTOCOL_MAJOR(conn->remoteVersion) != 0x200)
throw Error("unsupported 'nix-store --serve' protocol version on '%s'", host);
} catch (EndOfFile & e) {
throw Error("cannot connect to '%1%'", host);
}
return conn;
};
string getUri() override
{
return uriScheme + host;
}
void queryPathInfoUncached(const Path & path,
Callback<std::shared_ptr<ValidPathInfo>> callback) noexcept override
{
try {
auto conn(connections->get());
debug("querying remote host '%s' for info on '%s'", host, path);
conn->to << cmdQueryPathInfos << PathSet{path};
conn->to.flush();
auto info = std::make_shared<ValidPathInfo>();
conn->from >> info->path;
if (info->path.empty()) return callback(nullptr);
assert(path == info->path);
PathSet references;
conn->from >> info->deriver;
info->references = readStorePaths<PathSet>(*this, conn->from);
readLongLong(conn->from); // download size
info->narSize = readLongLong(conn->from);
if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 4) {
auto s = readString(conn->from);
info->narHash = s.empty() ? Hash() : Hash(s);
conn->from >> info->ca;
info->sigs = readStrings<StringSet>(conn->from);
}
auto s = readString(conn->from);
assert(s == "");
callback(std::move(info));
} catch (...) { callback.rethrow(); }
}
void addToStore(const ValidPathInfo & info, Source & source,
RepairFlag repair, CheckSigsFlag checkSigs,
std::shared_ptr<FSAccessor> accessor) override
{
debug("adding path '%s' to remote host '%s'", info.path, host);
auto conn(connections->get());
if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 5) {
conn->to
<< cmdAddToStoreNar
<< info.path
<< info.deriver
<< info.narHash.to_string(Base16, false)
<< info.references
<< info.registrationTime
<< info.narSize
<< info.ultimate
<< info.sigs
<< info.ca;
try {
copyNAR(source, conn->to);
} catch (...) {
conn->good = false;
throw;
}
conn->to.flush();
} else {
conn->to
<< cmdImportPaths
<< 1;
try {
copyNAR(source, conn->to);
} catch (...) {
conn->good = false;
throw;
}
conn->to
<< exportMagic
<< info.path
<< info.references
<< info.deriver
<< 0
<< 0;
conn->to.flush();
}
if (readInt(conn->from) != 1)
throw Error("failed to add path '%s' to remote host '%s', info.path, host");
}
void narFromPath(const Path & path, Sink & sink) override
{
auto conn(connections->get());
conn->to << cmdDumpStorePath << path;
conn->to.flush();
copyNAR(conn->from, sink);
}
Path queryPathFromHashPart(const string & hashPart) override
{ unsupported("queryPathFromHashPart"); }
Path addToStore(const string & name, const Path & srcPath,
bool recursive, HashType hashAlgo,
PathFilter & filter, RepairFlag repair) override
{ unsupported("addToStore"); }
Path addTextToStore(const string & name, const string & s,
const PathSet & references, RepairFlag repair) override
{ unsupported("addTextToStore"); }
BuildResult buildDerivation(const Path & drvPath, const BasicDerivation & drv,
BuildMode buildMode) override
{
auto conn(connections->get());
conn->to
<< cmdBuildDerivation
<< drvPath
<< drv
<< settings.maxSilentTime
<< settings.buildTimeout;
if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 2)
conn->to
<< settings.maxLogSize;
if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 3)
conn->to
<< settings.buildRepeat
<< settings.enforceDeterminism;
conn->to.flush();
BuildResult status;
status.status = (BuildResult::Status) readInt(conn->from);
conn->from >> status.errorMsg;
if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 3)
conn->from >> status.timesBuilt >> status.isNonDeterministic >> status.startTime >> status.stopTime;
return status;
}
void ensurePath(const Path & path) override
{ unsupported("ensurePath"); }
void computeFSClosure(const PathSet & paths,
PathSet & out, bool flipDirection = false,
bool includeOutputs = false, bool includeDerivers = false) override
{
if (flipDirection || includeDerivers) {
Store::computeFSClosure(paths, out, flipDirection, includeOutputs, includeDerivers);
return;
}
auto conn(connections->get());
conn->to
<< cmdQueryClosure
<< includeOutputs
<< paths;
conn->to.flush();
auto res = readStorePaths<PathSet>(*this, conn->from);
out.insert(res.begin(), res.end());
}
PathSet queryValidPaths(const PathSet & paths,
SubstituteFlag maybeSubstitute = NoSubstitute) override
{
auto conn(connections->get());
conn->to
<< cmdQueryValidPaths
<< false // lock
<< maybeSubstitute
<< paths;
conn->to.flush();
return readStorePaths<PathSet>(*this, conn->from);
}
void connect() override
{
auto conn(connections->get());
}
unsigned int getProtocol() override
{
auto conn(connections->get());
return conn->remoteVersion;
}
};
static RegisterStoreImplementation regStore([](
const std::string & uri, const Store::Params & params)
-> std::shared_ptr<Store>
{
if (std::string(uri, 0, uriScheme.size()) != uriScheme) return 0;
return std::make_shared<LegacySSHStore>(std::string(uri, uriScheme.size()), params);
});
}