Support multiple machines files

This is primarily useful for the Hydra provisioner, which can write
its machines to another file than /etc/nix/machines.
This commit is contained in:
Eelco Dolstra 2015-08-25 14:11:50 +02:00
parent 442bed3b59
commit 7aa52517e9
3 changed files with 63 additions and 34 deletions

View file

@ -22,33 +22,14 @@ State::State()
logDir = canonPath(hydraData + "/build-logs"); logDir = canonPath(hydraData + "/build-logs");
machinesFile = getEnv("NIX_REMOTE_SYSTEMS", "/etc/nix/machines");
machinesFileStat.st_ino = 0;
machinesFileStat.st_mtime = 0;
localPlatforms = {settings.thisSystem}; localPlatforms = {settings.thisSystem};
if (settings.thisSystem == "x86_64-linux") if (settings.thisSystem == "x86_64-linux")
localPlatforms.insert("i686-linux"); localPlatforms.insert("i686-linux");
} }
void State::loadMachinesFile() void State::parseMachines(const std::string & contents)
{ {
string contents;
if (pathExists(machinesFile)) {
struct stat st;
if (stat(machinesFile.c_str(), &st) != 0)
throw SysError(format("getting stats about %1%") % machinesFile);
if (st.st_ino == machinesFileStat.st_ino && st.st_mtime == machinesFileStat.st_mtime)
return;
printMsg(lvlDebug, "reloading machines");
contents = readFile(machinesFile);
machinesFileStat = st;
} else {
contents = "localhost " + concatStringsSep(",", localPlatforms)
+ " - " + int2String(settings.maxBuildJobs) + " 1";
}
Machines newMachines, oldMachines; Machines newMachines, oldMachines;
{ {
auto machines_(machines.lock()); auto machines_(machines.lock());
@ -103,11 +84,63 @@ void State::loadMachinesFile()
void State::monitorMachinesFile() void State::monitorMachinesFile()
{ {
string defaultMachinesFile = "/etc/nix/machines";
auto machinesFiles = tokenizeString<std::vector<Path>>(
getEnv("NIX_REMOTE_SYSTEMS", pathExists(defaultMachinesFile) ? defaultMachinesFile : ""), ":");
if (machinesFiles.empty()) {
parseMachines("localhost " + concatStringsSep(",", localPlatforms)
+ " - " + int2String(settings.maxBuildJobs) + " 1");
return;
}
std::vector<struct stat> fileStats;
fileStats.resize(machinesFiles.size());
for (unsigned int n = 0; n < machinesFiles.size(); ++n) {
auto & st(fileStats[n]);
st.st_ino = st.st_mtime = 0;
}
auto readMachinesFiles = [&]() {
/* Check if any of the machines files changed. */
bool anyChanged = false;
for (unsigned int n = 0; n < machinesFiles.size(); ++n) {
Path machinesFile = machinesFiles[n];
struct stat st;
if (stat(machinesFile.c_str(), &st) != 0) {
if (errno != ENOENT)
throw SysError(format("getting stats about %1%") % machinesFile);
st.st_ino = st.st_mtime = 0;
}
auto & old(fileStats[n]);
if (old.st_ino != st.st_ino || old.st_mtime != st.st_mtime)
anyChanged = true;
old = st;
}
if (!anyChanged) return;
debug("reloading machines files");
string contents;
for (auto & machinesFile : machinesFiles) {
try {
contents += readFile(machinesFile);
contents += '\n';
} catch (SysError & e) {
if (e.errNo != ENOENT) throw;
}
}
parseMachines(contents);
};
while (true) { while (true) {
try { try {
readMachinesFiles();
// FIXME: use inotify. // FIXME: use inotify.
sleep(60); sleep(30);
loadMachinesFile();
} catch (std::exception & e) { } catch (std::exception & e) {
printMsg(lvlError, format("reloading machines file: %1%") % e.what()); printMsg(lvlError, format("reloading machines file: %1%") % e.what());
} }
@ -587,8 +620,6 @@ void State::run(BuildID buildOne)
dumpStatus(*conn, false); dumpStatus(*conn, false);
} }
loadMachinesFile();
std::thread(&State::monitorMachinesFile, this).detach(); std::thread(&State::monitorMachinesFile, this).detach();
std::thread(&State::queueMonitor, this).detach(); std::thread(&State::queueMonitor, this).detach();

View file

@ -286,9 +286,6 @@ private:
typedef std::map<std::string, Machine::ptr> Machines; typedef std::map<std::string, Machine::ptr> Machines;
Sync<Machines> machines; // FIXME: use atomic_shared_ptr Sync<Machines> machines; // FIXME: use atomic_shared_ptr
nix::Path machinesFile;
struct stat machinesFileStat;
/* Various stats. */ /* Various stats. */
time_t startedAt; time_t startedAt;
counter nrBuildsRead{0}; counter nrBuildsRead{0};
@ -352,8 +349,7 @@ private:
void clearBusy(Connection & conn, time_t stopTime); void clearBusy(Connection & conn, time_t stopTime);
/* (Re)load /etc/nix/machines. */ void parseMachines(const std::string & contents);
void loadMachinesFile();
/* Thread to reload /etc/nix/machines periodically. */ /* Thread to reload /etc/nix/machines periodically. */
void monitorMachinesFile(); void monitorMachinesFile();

View file

@ -286,12 +286,13 @@ sub getEvals {
sub getMachines { sub getMachines {
my $machinesConf = $ENV{"NIX_REMOTE_SYSTEMS"} || "/etc/nix/machines";
# Read the list of machines.
my %machines = (); my %machines = ();
if (-e $machinesConf) {
open CONF, "<$machinesConf" or die; my @machinesFiles = split /:/, ($ENV{"NIX_REMOTE_SYSTEMS"} || "/etc/nix/machines");
for my $machinesFile (@machinesFiles) {
next unless -e $machinesFile;
open CONF, "<$machinesFile" or die;
while (<CONF>) { while (<CONF>) {
chomp; chomp;
s/\#.*$//g; s/\#.*$//g;
@ -310,6 +311,7 @@ sub getMachines {
} }
close CONF; close CONF;
} }
return \%machines; return \%machines;
} }