lix/src/nix/main.cc
John Ericson 7c4dea3cf3 Punt on improper global flags for now
See the note in the test.

We don't want these flags showing up for commands where they are
irrelevant.

Eventually, this needs a proper fix, but it need not be a blocker for
stabilize: for a quick-n-dirty punt, just put these flags behind the
`nix-command` unstable feature.

This is fine because they are only relevant for commands which we don't
need to stabilize for a while.
2023-03-27 09:21:50 -04:00

419 lines
12 KiB
C++

#include <algorithm>
#include "command.hh"
#include "common-args.hh"
#include "eval.hh"
#include "globals.hh"
#include "legacy.hh"
#include "shared.hh"
#include "store-api.hh"
#include "filetransfer.hh"
#include "finally.hh"
#include "loggers.hh"
#include "markdown.hh"
#include <sys/types.h>
#include <sys/socket.h>
#include <ifaddrs.h>
#include <netdb.h>
#include <netinet/in.h>
#include <nlohmann/json.hpp>
extern std::string chrootHelperName;
void chrootHelper(int argc, char * * argv);
namespace nix {
/* Check if we have a non-loopback/link-local network interface. */
static bool haveInternet()
{
struct ifaddrs * addrs;
if (getifaddrs(&addrs))
return true;
Finally free([&]() { freeifaddrs(addrs); });
for (auto i = addrs; i; i = i->ifa_next) {
if (!i->ifa_addr) continue;
if (i->ifa_addr->sa_family == AF_INET) {
if (ntohl(((sockaddr_in *) i->ifa_addr)->sin_addr.s_addr) != INADDR_LOOPBACK) {
return true;
}
} else if (i->ifa_addr->sa_family == AF_INET6) {
if (!IN6_IS_ADDR_LOOPBACK(&((sockaddr_in6 *) i->ifa_addr)->sin6_addr) &&
!IN6_IS_ADDR_LINKLOCAL(&((sockaddr_in6 *) i->ifa_addr)->sin6_addr))
return true;
}
}
return false;
}
std::string programPath;
struct NixArgs : virtual MultiCommand, virtual MixCommonArgs
{
bool useNet = true;
bool refresh = false;
bool helpRequested = false;
bool showVersion = false;
NixArgs() : MultiCommand(RegisterCommand::getCommandsFor({})), MixCommonArgs("nix")
{
categories.clear();
categories[Command::catDefault] = "Main commands";
categories[catSecondary] = "Infrequently used commands";
categories[catUtility] = "Utility/scripting commands";
categories[catNixInstallation] = "Commands for upgrading or troubleshooting your Nix installation";
addFlag({
.longName = "help",
.description = "Show usage information.",
.category = miscCategory,
.handler = {[this]() { this->helpRequested = true; }},
});
addFlag({
.longName = "print-build-logs",
.shortName = 'L',
.description = "Print full build logs on standard error.",
.category = loggingCategory,
.handler = {[&]() { logger->setPrintBuildLogs(true); }},
.experimentalFeature = Xp::NixCommand,
});
addFlag({
.longName = "version",
.description = "Show version information.",
.category = miscCategory,
.handler = {[&]() { showVersion = true; }},
});
addFlag({
.longName = "offline",
.aliases = {"no-net"}, // FIXME: remove
.description = "Disable substituters and consider all previously downloaded files up-to-date.",
.category = miscCategory,
.handler = {[&]() { useNet = false; }},
.experimentalFeature = Xp::NixCommand,
});
addFlag({
.longName = "refresh",
.description = "Consider all previously downloaded files out-of-date.",
.category = miscCategory,
.handler = {[&]() { refresh = true; }},
.experimentalFeature = Xp::NixCommand,
});
}
std::map<std::string, std::vector<std::string>> aliases = {
{"add-to-store", {"store", "add-path"}},
{"cat-nar", {"nar", "cat"}},
{"cat-store", {"store", "cat"}},
{"copy-sigs", {"store", "copy-sigs"}},
{"dev-shell", {"develop"}},
{"diff-closures", {"store", "diff-closures"}},
{"dump-path", {"store", "dump-path"}},
{"hash-file", {"hash", "file"}},
{"hash-path", {"hash", "path"}},
{"ls-nar", {"nar", "ls"}},
{"ls-store", {"store", "ls"}},
{"make-content-addressable", {"store", "make-content-addressed"}},
{"optimise-store", {"store", "optimise"}},
{"ping-store", {"store", "ping"}},
{"sign-paths", {"store", "sign"}},
{"to-base16", {"hash", "to-base16"}},
{"to-base32", {"hash", "to-base32"}},
{"to-base64", {"hash", "to-base64"}},
{"verify", {"store", "verify"}},
};
bool aliasUsed = false;
Strings::iterator rewriteArgs(Strings & args, Strings::iterator pos) override
{
if (aliasUsed || command || pos == args.end()) return pos;
auto arg = *pos;
auto i = aliases.find(arg);
if (i == aliases.end()) return pos;
warn("'%s' is a deprecated alias for '%s'",
arg, concatStringsSep(" ", i->second));
pos = args.erase(pos);
for (auto j = i->second.rbegin(); j != i->second.rend(); ++j)
pos = args.insert(pos, *j);
aliasUsed = true;
return pos;
}
std::string description() override
{
return "a tool for reproducible and declarative configuration management";
}
std::string doc() override
{
return
#include "nix.md"
;
}
// Plugins may add new subcommands.
void pluginsInited() override
{
commands = RegisterCommand::getCommandsFor({});
}
};
/* Render the help for the specified subcommand to stdout using
lowdown. */
static void showHelp(std::vector<std::string> subcommand, MultiCommand & toplevel)
{
auto mdName = subcommand.empty() ? "nix" : fmt("nix3-%s", concatStringsSep("-", subcommand));
evalSettings.restrictEval = false;
evalSettings.pureEval = false;
EvalState state({}, openStore("dummy://"));
auto vGenerateManpage = state.allocValue();
state.eval(state.parseExprFromString(
#include "generate-manpage.nix.gen.hh"
, "/"), *vGenerateManpage);
auto vUtils = state.allocValue();
state.cacheFile(
"/utils.nix", "/utils.nix",
state.parseExprFromString(
#include "utils.nix.gen.hh"
, "/"),
*vUtils);
auto attrs = state.buildBindings(16);
attrs.alloc("toplevel").mkString(toplevel.toJSON().dump());
auto vRes = state.allocValue();
state.callFunction(*vGenerateManpage, state.allocValue()->mkAttrs(attrs), *vRes, noPos);
auto attr = vRes->attrs->get(state.symbols.create(mdName + ".md"));
if (!attr)
throw UsageError("Nix has no subcommand '%s'", concatStringsSep("", subcommand));
auto markdown = state.forceString(*attr->value, noPos, "while evaluating the lowdown help text");
RunPager pager;
std::cout << renderMarkdownToTerminal(markdown) << "\n";
}
struct CmdHelp : Command
{
std::vector<std::string> subcommand;
CmdHelp()
{
expectArgs({
.label = "subcommand",
.handler = {&subcommand},
});
}
std::string description() override
{
return "show help about `nix` or a particular subcommand";
}
std::string doc() override
{
return
#include "help.md"
;
}
void run() override
{
assert(parent);
MultiCommand * toplevel = parent;
while (toplevel->parent) toplevel = toplevel->parent;
showHelp(subcommand, *toplevel);
}
};
static auto rCmdHelp = registerCommand<CmdHelp>("help");
void mainWrapped(int argc, char * * argv)
{
savedArgv = argv;
/* The chroot helper needs to be run before any threads have been
started. */
if (argc > 0 && argv[0] == chrootHelperName) {
chrootHelper(argc, argv);
return;
}
initNix();
initGC();
#if __linux__
if (getuid() == 0) {
try {
saveMountNamespace();
if (unshare(CLONE_NEWNS) == -1)
throw SysError("setting up a private mount namespace");
} catch (Error & e) { }
}
#endif
Finally f([] { logger->stop(); });
programPath = argv[0];
auto programName = std::string(baseNameOf(programPath));
if (argc > 1 && std::string_view(argv[1]) == "__build-remote") {
programName = "build-remote";
argv++; argc--;
}
{
auto legacy = (*RegisterLegacyCommand::commands)[programName];
if (legacy) return legacy(argc, argv);
}
evalSettings.pureEval = true;
setLogFormat("bar");
settings.verboseBuild = false;
if (isatty(STDERR_FILENO)) {
verbosity = lvlNotice;
} else {
verbosity = lvlInfo;
}
NixArgs args;
if (argc == 2 && std::string(argv[1]) == "__dump-args") {
logger->cout("%s", args.toJSON());
return;
}
if (argc == 2 && std::string(argv[1]) == "__dump-builtins") {
experimentalFeatureSettings.experimentalFeatures = {
Xp::Flakes,
Xp::FetchClosure,
};
evalSettings.pureEval = false;
EvalState state({}, openStore("dummy://"));
auto res = nlohmann::json::object();
auto builtins = state.baseEnv.values[0]->attrs;
for (auto & builtin : *builtins) {
auto b = nlohmann::json::object();
if (!builtin.value->isPrimOp()) continue;
auto primOp = builtin.value->primOp;
if (!primOp->doc) continue;
b["arity"] = primOp->arity;
b["args"] = primOp->args;
b["doc"] = trim(stripIndentation(primOp->doc));
res[state.symbols[builtin.name]] = std::move(b);
}
logger->cout("%s", res);
return;
}
Finally printCompletions([&]()
{
if (completions) {
switch (completionType) {
case ctNormal:
logger->cout("normal"); break;
case ctFilenames:
logger->cout("filenames"); break;
case ctAttrs:
logger->cout("attrs"); break;
}
for (auto & s : *completions)
logger->cout(s.completion + "\t" + trim(s.description));
}
});
try {
args.parseCmdline(argvToStrings(argc, argv));
} catch (UsageError &) {
if (!args.helpRequested && !completions) throw;
}
if (args.helpRequested) {
std::vector<std::string> subcommand;
MultiCommand * command = &args;
while (command) {
if (command && command->command) {
subcommand.push_back(command->command->first);
command = dynamic_cast<MultiCommand *>(&*command->command->second);
} else
break;
}
showHelp(subcommand, args);
return;
}
if (completions) {
args.completionHook();
return;
}
if (args.showVersion) {
printVersion(programName);
return;
}
if (!args.command)
throw UsageError("no subcommand specified");
if (args.command->first != "repl"
&& args.command->first != "doctor"
&& args.command->first != "upgrade-nix")
experimentalFeatureSettings.require(Xp::NixCommand);
if (args.useNet && !haveInternet()) {
warn("you don't have Internet access; disabling some network-dependent features");
args.useNet = false;
}
if (!args.useNet) {
// FIXME: should check for command line overrides only.
if (!settings.useSubstitutes.overridden)
settings.useSubstitutes = false;
if (!settings.tarballTtl.overridden)
settings.tarballTtl = std::numeric_limits<unsigned int>::max();
if (!fileTransferSettings.tries.overridden)
fileTransferSettings.tries = 0;
if (!fileTransferSettings.connectTimeout.overridden)
fileTransferSettings.connectTimeout = 1;
}
if (args.refresh) {
settings.tarballTtl = 0;
settings.ttlNegativeNarInfoCache = 0;
settings.ttlPositiveNarInfoCache = 0;
}
if (args.command->second->forceImpureByDefault() && !evalSettings.pureEval.overridden) {
evalSettings.pureEval = false;
}
args.command->second->run();
}
}
int main(int argc, char * * argv)
{
// Increase the default stack size for the evaluator and for
// libstdc++'s std::regex.
nix::setStackSize(64 * 1024 * 1024);
return nix::handleExceptions(argv[0], [&]() {
nix::mainWrapped(argc, argv);
});
}