nix-eval-jobs/src/nix-eval-jobs.cc

418 lines
14 KiB
C++

#include <map>
#include <iostream>
#include <thread>
#include <nix/config.h>
#include <nix/shared.hh>
#include <nix/store-api.hh>
#include <nix/eval.hh>
#include <nix/eval-inline.hh>
#include <nix/util.hh>
#include <nix/get-drvs.hh>
#include <nix/globals.hh>
#include <nix/common-eval-args.hh>
#include <nix/flake/flakeref.hh>
#include <nix/flake/flake.hh>
#include <nix/attr-path.hh>
#include <nix/derivations.hh>
#include <nix/local-fs-store.hh>
#include <nix/value-to-json.hh>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/resource.h>
#include <nlohmann/json.hpp>
using namespace nix;
typedef enum { evalAuto, evalImpure, evalPure } pureEval;
struct MyArgs : MixEvalArgs, MixCommonArgs
{
Path releaseExpr;
Path gcRootsDir;
bool flake = false;
size_t nrWorkers = 1;
size_t maxMemorySize = 4096;
pureEval evalMode = evalAuto;
MyArgs() : MixCommonArgs("nix-eval-jobs")
{
addFlag({
.longName = "help",
.description = "show usage information",
.handler = {[&]() {
printf("USAGE: nix-eval-jobs [options] expr\n\n");
for (const auto & [name, flag] : longFlags) {
if (hiddenCategories.count(flag->category)) {
continue;
}
printf(" --%-20s %s\n", name.c_str(), flag->description.c_str());
}
::exit(0);
}},
});
addFlag({
.longName = "impure",
.description = "set evaluation mode",
.handler = {[&]() {
evalMode = evalImpure;
}},
});
addFlag({
.longName = "gc-roots-dir",
.description = "garbage collector roots directory",
.labels = {"path"},
.handler = {&gcRootsDir}
});
addFlag({
.longName = "workers",
.description = "number of evaluate workers",
.labels = {"workers"},
.handler = {[=](std::string s) {
nrWorkers = std::stoi(s);
}}
});
addFlag({
.longName = "max-memory-size",
.description = "maximum evaluation memory size",
.labels = {"size"},
.handler = {[=](std::string s) {
maxMemorySize = std::stoi(s);
}}
});
addFlag({
.longName = "flake",
.description = "build a flake",
.handler = {&flake, true}
});
expectArg("expr", &releaseExpr);
}
};
static MyArgs myArgs;
static void worker(
EvalState & state,
Bindings & autoArgs,
AutoCloseFD & to,
AutoCloseFD & from,
const Path &gcRootsDir)
{
Value vTop;
if (myArgs.flake) {
using namespace flake;
auto flakeRef = parseFlakeRef(myArgs.releaseExpr, absPath("."));
auto vFlake = state.allocValue();
auto lockedFlake = lockFlake(state, flakeRef,
LockFlags {
.updateLockFile = false,
.useRegistries = false,
.allowMutable = false,
});
callFlake(state, lockedFlake, *vFlake);
auto vOutputs = vFlake->attrs->get(state.symbols.create("outputs"))->value;
state.forceValue(*vOutputs);
auto aHydraJobs = vOutputs->attrs->get(state.symbols.create("hydraJobs"));
if (!aHydraJobs)
aHydraJobs = vOutputs->attrs->get(state.symbols.create("checks"));
if (!aHydraJobs)
throw Error("flake '%s' does not provide any Hydra jobs or checks", flakeRef);
vTop = *aHydraJobs->value;
} else {
state.evalFile(lookupFileArg(state, myArgs.releaseExpr), vTop);
}
auto vRoot = state.allocValue();
state.autoCallFunction(autoArgs, vTop, *vRoot);
while (true) {
/* Wait for the master to send us a job name. */
writeLine(to.get(), "next");
auto s = readLine(from.get());
if (s == "exit") break;
if (!hasPrefix(s, "do ")) abort();
std::string attrPath(s, 3);
debug("worker process %d at '%s'", getpid(), attrPath);
/* Evaluate it and send info back to the master. */
nlohmann::json reply;
reply["attr"] = attrPath;
try {
auto vTmp = findAlongAttrPath(state, attrPath, autoArgs, *vRoot).first;
auto v = state.allocValue();
state.autoCallFunction(autoArgs, *vTmp, *v);
if (auto drv = getDerivation(state, *v, false)) {
if (drv->querySystem() == "unknown")
throw EvalError("derivation must have a 'system' attribute");
auto drvPath = drv->queryDrvPath();
nlohmann::json job;
job["nixName"] = drv->queryName();
job["system"] =drv->querySystem();
job["drvPath"] = drvPath;
nlohmann::json meta;
for (auto & name : drv->queryMetaNames()) {
PathSet context;
std::stringstream ss;
auto metaValue = drv->queryMeta(name);
// Skip non-serialisable types
// TODO: Fix serialisation of derivations to store paths
if (metaValue == 0) {
continue;
}
printValueAsJSON(state, true, *metaValue, ss, context);
nlohmann::json field = nlohmann::json::parse(ss.str());
meta[name] = field;
}
job["meta"] = meta;
/* Register the derivation as a GC root. !!! This
registers roots for jobs that we may have already
done. */
auto localStore = state.store.dynamic_pointer_cast<LocalFSStore>();
auto storePath = localStore->parseStorePath(drvPath);
if (gcRootsDir != "" && localStore) {
Path root = gcRootsDir + "/" + std::string(baseNameOf(drvPath));
if (!pathExists(root))
localStore->addPermRoot(storePath, root);
}
DrvInfo::Outputs outputs = drv->queryOutputs();
nlohmann::json out;
for (auto & p : outputs) {
out[p.first] = p.second;
}
job["outputs"] = std::move(out);
reply["job"] = std::move(job);
}
else if (v->type() == nAttrs)
{
auto attrs = nlohmann::json::array();
StringSet ss;
for (auto & i : v->attrs->lexicographicOrder()) {
std::string name(i->name);
if (name.find('.') != std::string::npos || name.find(' ') != std::string::npos) {
printError("skipping job with illegal name '%s'", name);
continue;
}
attrs.push_back(name);
}
reply["attrs"] = std::move(attrs);
}
else if (v->type() == nNull)
;
else throw TypeError("attribute '%s' is %s, which is not supported", attrPath, showType(*v));
} catch (EvalError & e) {
auto msg = e.msg();
// Transmits the error we got from the previous evaluation
// in the JSON output.
reply["error"] = filterANSIEscapes(msg, true);
// Don't forget to print it into the STDERR log, this is
// what's shown in the Hydra UI.
printError(msg);
}
writeLine(to.get(), reply.dump());
/* If our RSS exceeds the maximum, exit. The master will
start a new process. */
struct rusage r;
getrusage(RUSAGE_SELF, &r);
if ((size_t) r.ru_maxrss > myArgs.maxMemorySize * 1024) break;
}
writeLine(to.get(), "restart");
}
int main(int argc, char * * argv)
{
/* Prevent undeclared dependencies in the evaluation via
$NIX_PATH. */
unsetenv("NIX_PATH");
return handleExceptions(argv[0], [&]() {
initNix();
initGC();
myArgs.parseCmdline(argvToStrings(argc, argv));
/* FIXME: The build hook in conjunction with import-from-derivation is causing "unexpected EOF" during eval */
settings.builders = "";
/* Prevent access to paths outside of the Nix search path and
to the environment. */
evalSettings.restrictEval = false;
/* When building a flake, use pure evaluation (no access to
'getEnv', 'currentSystem' etc. */
evalSettings.pureEval = myArgs.evalMode == evalAuto ? myArgs.flake : myArgs.evalMode == evalPure;
if (myArgs.releaseExpr == "") throw UsageError("no expression specified");
if (myArgs.gcRootsDir == "") printMsg(lvlError, "warning: `--gc-roots-dir' not specified");
struct State
{
std::set<std::string> todo{""};
std::set<std::string> active;
std::exception_ptr exc;
};
std::condition_variable wakeup;
Sync<State> state_;
/* Start a handler thread per worker process. */
auto handler = [&]()
{
try {
pid_t pid = -1;
AutoCloseFD from, to;
while (true) {
/* Start a new worker process if necessary. */
if (pid == -1) {
Pipe toPipe, fromPipe;
toPipe.create();
fromPipe.create();
pid = startProcess(
[&,
to{std::make_shared<AutoCloseFD>(std::move(fromPipe.writeSide))},
from{std::make_shared<AutoCloseFD>(std::move(toPipe.readSide))}
]()
{
try {
EvalState state(myArgs.searchPath, openStore());
Bindings & autoArgs = *myArgs.getAutoArgs(state);
worker(state, autoArgs, *to, *from, myArgs.gcRootsDir);
} catch (Error & e) {
nlohmann::json err;
auto msg = e.msg();
err["error"] = filterANSIEscapes(msg, true);
printError(msg);
writeLine(to->get(), err.dump());
// Don't forget to print it into the STDERR log, this is
// what's shown in the Hydra UI.
writeLine(to->get(), "restart");
}
},
ProcessOptions { .allowVfork = false });
from = std::move(fromPipe.readSide);
to = std::move(toPipe.writeSide);
debug("created worker process %d", pid);
}
/* Check whether the existing worker process is still there. */
auto s = readLine(from.get());
if (s == "restart") {
pid = -1;
continue;
} else if (s != "next") {
auto json = nlohmann::json::parse(s);
throw Error("worker error: %s", (std::string) json["error"]);
}
/* Wait for a job name to become available. */
std::string attrPath;
while (true) {
checkInterrupt();
auto state(state_.lock());
if ((state->todo.empty() && state->active.empty()) || state->exc) {
writeLine(to.get(), "exit");
return;
}
if (!state->todo.empty()) {
attrPath = *state->todo.begin();
state->todo.erase(state->todo.begin());
state->active.insert(attrPath);
break;
} else
state.wait(wakeup);
}
/* Tell the worker to evaluate it. */
writeLine(to.get(), "do " + attrPath);
/* Wait for the response. */
auto respString = readLine(from.get());
auto response = nlohmann::json::parse(respString);
/* Handle the response. */
StringSet newAttrs;
if (response.find("attrs") != response.end()) {
for (auto & i : response["attrs"]) {
auto s = (attrPath.empty() ? "" : attrPath + ".") + (std::string) i;
newAttrs.insert(s);
}
} else {
auto state(state_.lock());
std::cout << respString << "\n";
}
/* Add newly discovered job names to the queue. */
{
auto state(state_.lock());
state->active.erase(attrPath);
for (auto & s : newAttrs)
state->todo.insert(s);
wakeup.notify_all();
}
}
} catch (...) {
auto state(state_.lock());
state->exc = std::current_exception();
wakeup.notify_all();
}
};
std::vector<std::thread> threads;
for (size_t i = 0; i < myArgs.nrWorkers; i++)
threads.emplace_back(std::thread(handler));
for (auto & thread : threads)
thread.join();
auto state(state_.lock());
if (state->exc)
std::rethrow_exception(state->exc);
});
}