void createServerInstanceDirAndGeneration(ServerInstanceDirPtr &serverInstanceDir,
ServerInstanceDir::GenerationPtr &generation)
{
serverInstanceDir.reset(new ServerInstanceDir(getpid()));
generation = serverInstanceDir->newGeneration(geteuid() == 0,
"nobody", getPrimaryGroupName("nobody"),
geteuid(), getegid());
}
int
main(int argc, char *argv[]) {
disableOomKiller();
agentsOptions = initializeAgent(argc, argv, "PassengerWatchdog");
logLevel = agentsOptions.getInt("log_level");
webServerPid = agentsOptions.getPid("web_server_pid");
tempDir = agentsOptions.get("temp_dir");
userSwitching = agentsOptions.getBool("user_switching");
defaultUser = agentsOptions.get("default_user");
defaultGroup = agentsOptions.get("default_group");
webServerWorkerUid = agentsOptions.getUid("web_server_worker_uid");
webServerWorkerGid = agentsOptions.getGid("web_server_worker_gid");
passengerRoot = agentsOptions.get("passenger_root");
rubyCommand = agentsOptions.get("ruby");
maxPoolSize = agentsOptions.getInt("max_pool_size");
maxInstancesPerApp = agentsOptions.getInt("max_instances_per_app");
poolIdleTime = agentsOptions.getInt("pool_idle_time");
serializedPrestartURLs = agentsOptions.get("prestart_urls");
try {
randomGenerator = new RandomGenerator();
errorEvent = new EventFd();
MessageChannel feedbackChannel(FEEDBACK_FD);
serverInstanceDir.reset(new ServerInstanceDir(webServerPid, tempDir));
generation = serverInstanceDir->newGeneration(userSwitching, defaultUser,
defaultGroup, webServerWorkerUid, webServerWorkerGid);
agentsOptions.set("server_instance_dir", serverInstanceDir->getPath());
agentsOptions.setInt("generation_number", generation->getNumber());
ServerInstanceDirToucher serverInstanceDirToucher;
ResourceLocator resourceLocator(passengerRoot);
if (agentsOptions.get("analytics_server", false).empty()) {
// Using local, server instance specific logging agent.
loggingAgentAddress = "unix:" + generation->getPath() + "/logging.socket";
loggingAgentPassword = randomGenerator->generateAsciiString(64);
} else {
// Using remote logging agent.
loggingAgentAddress = agentsOptions.get("analytics_server");
}
HelperAgentWatcher helperAgentWatcher(resourceLocator);
LoggingAgentWatcher loggingAgentWatcher(resourceLocator);
vector<AgentWatcher *> watchers;
vector<AgentWatcher *>::iterator it;
watchers.push_back(&helperAgentWatcher);
if (agentsOptions.get("analytics_server", false).empty()) {
watchers.push_back(&loggingAgentWatcher);
}
for (it = watchers.begin(); it != watchers.end(); it++) {
try {
(*it)->start();
} catch (const std::exception &e) {
feedbackChannel.write("Watchdog startup error",
e.what(), NULL);
forceAllAgentsShutdown(watchers);
return 1;
}
// Allow other exceptions to propagate and crash the watchdog.
}
for (it = watchers.begin(); it != watchers.end(); it++) {
try {
(*it)->startWatching();
} catch (const std::exception &e) {
feedbackChannel.write("Watchdog startup error",
e.what(), NULL);
forceAllAgentsShutdown(watchers);
return 1;
}
// Allow other exceptions to propagate and crash the watchdog.
}
feedbackChannel.write("Basic startup info",
serverInstanceDir->getPath().c_str(),
toString(generation->getNumber()).c_str(),
NULL);
for (it = watchers.begin(); it != watchers.end(); it++) {
(*it)->sendStartupInfo(feedbackChannel);
}
feedbackChannel.write("All agents started", NULL);
this_thread::disable_interruption di;
this_thread::disable_syscall_interruption dsi;
bool exitGracefully = waitForStarterProcessOrWatchers(watchers);
AgentWatcher::stopWatching(watchers);
if (exitGracefully) {
/* Fork a child process which cleans up all the agent processes in
* the background and exit this watchdog process so that we don't block
* the web server.
*/
cleanupAgentsInBackground(watchers);
return 0;
} else {
P_DEBUG("Web server did not exit gracefully, forcing shutdown of all service processes...");
forceAllAgentsShutdown(watchers);
return 1;
}
} catch (const tracable_exception &e) {
P_ERROR(e.what() << "\n" << e.backtrace());
return 1;
} catch (const std::exception &e) {
P_ERROR(e.what());
return 1;
}
}
static void
threadMain() {
while (!this_thread::interruption_requested()) {
syscalls::sleep(60 * 60 * 6);
begin_touch:
this_thread::disable_interruption di;
this_thread::disable_syscall_interruption dsi;
// Fork a process which touches everything in the server instance dir.
pid_t pid = syscalls::fork();
if (pid == 0) {
// Child
int prio, ret, e;
closeAllFileDescriptors(2);
// Make process nicer.
do {
prio = getpriority(PRIO_PROCESS, getpid());
} while (prio == -1 && errno == EINTR);
if (prio != -1) {
prio++;
if (prio > 20) {
prio = 20;
}
do {
ret = setpriority(PRIO_PROCESS, getpid(), prio);
} while (ret == -1 && errno == EINTR);
} else {
perror("getpriority");
}
do {
ret = chdir(serverInstanceDir->getPath().c_str());
} while (ret == -1 && errno == EINTR);
if (ret == -1) {
e = errno;
fprintf(stderr, "chdir(\"%s\") failed: %s (%d)\n",
serverInstanceDir->getPath().c_str(),
strerror(e), e);
fflush(stderr);
_exit(1);
}
execlp("/bin/sh", "/bin/sh", "-c", "find . | xargs touch", (char *) 0);
e = errno;
fprintf(stderr, "Cannot execute 'find . | xargs touch': %s (%d)\n",
strerror(e), e);
fflush(stderr);
_exit(1);
} else if (pid == -1) {
// Error
P_WARN("Could touch the server instance directory because "
"fork() failed. Retrying in 2 minutes...");
this_thread::restore_interruption si(di);
this_thread::restore_syscall_interruption rsi(dsi);
syscalls::sleep(60 * 2);
goto begin_touch;
} else {
syscalls::waitpid(pid, NULL, 0);
}
}
}
static void
cleanupAgentsInBackground(vector<AgentWatcher *> &watchers) {
this_thread::disable_interruption di;
this_thread::disable_syscall_interruption dsi;
pid_t pid;
int e;
pid = fork();
if (pid == 0) {
// Child
vector<AgentWatcher *>::const_iterator it;
Timer timer(false);
fd_set fds, fds2;
int max, agentProcessesDone;
unsigned long long deadline = 30000; // miliseconds
// Wait until all agent processes have exited.
max = 0;
FD_ZERO(&fds);
for (it = watchers.begin(); it != watchers.end(); it++) {
FD_SET((*it)->getFeedbackFd(), &fds);
if ((*it)->getFeedbackFd() > max) {
max = (*it)->getFeedbackFd();
}
}
timer.start();
agentProcessesDone = 0;
while (agentProcessesDone != -1
&& agentProcessesDone < (int) watchers.size()
&& timer.elapsed() < deadline)
{
struct timeval timeout;
#ifdef FD_COPY
FD_COPY(&fds, &fds2);
#else
FD_ZERO(&fds2);
for (it = watchers.begin(); it != watchers.end(); it++) {
FD_SET((*it)->getFeedbackFd(), &fds2);
}
#endif
timeout.tv_sec = 0;
timeout.tv_usec = 10000;
agentProcessesDone = syscalls::select(max + 1, &fds2, NULL, NULL, &timeout);
if (agentProcessesDone > 0 && timer.elapsed() < deadline) {
usleep(10000);
}
}
if (agentProcessesDone == -1 || timer.elapsed() >= deadline) {
// An error occurred or we've waited long enough. Kill all the
// processes.
P_WARN("Some Phusion Passenger agent processes did not exit " <<
"in time, forcefully shutting down all.");
for (it = watchers.begin(); it != watchers.end(); it++) {
(*it)->forceShutdown();
}
} else {
P_DEBUG("All Phusion Passenger agent processes have exited.");
}
// Now clean up the server instance directory.
delete generation.get();
delete serverInstanceDir.get();
_exit(0);
} else if (pid == -1) {
// Error
e = errno;
throw SystemException("fork() failed", errno);
} else {
// Parent
// Let child process handle cleanup.
serverInstanceDir->detach();
generation->detach();
}
}
int
main(int argc, char *argv[]) {
/*
* Some Apache installations (like on OS X) redirect stdout to /dev/null,
* so that only stderr is redirected to the log file. We therefore
* forcefully redirect stdout to stderr so that everything ends up in the
* same place.
*/
dup2(2, 1);
/*
* Most operating systems overcommit memory. We *know* that this watchdog process
* doesn't use much memory; on OS X it uses about 200 KB of private RSS. If the
* watchdog is killed by the system Out-Of-Memory Killer or then it's all over:
* the system administrator will have to restart the web server for Phusion
* Passenger to be usable again. So here we disable Linux's OOM killer
* for this watchdog. Note that the OOM score is inherited by child processes
* so we need to restore it after each fork().
*/
oldOomScore = setOomScoreNeverKill();
agentsOptions = initializeAgent(argc, argv, "PassengerWatchdog");
agentsOptions
.setDefaultInt ("log_level", DEFAULT_LOG_LEVEL)
.setDefault ("temp_dir", getSystemTempDir())
.setDefaultBool("user_switching", true)
.setDefault ("default_user", DEFAULT_WEB_APP_USER)
.setDefaultUid ("web_server_worker_uid", getuid())
.setDefaultGid ("web_server_worker_gid", getgid())
.setDefault ("ruby", DEFAULT_RUBY)
.setDefault ("python", DEFAULT_PYTHON)
.setDefaultInt ("max_pool_size", DEFAULT_MAX_POOL_SIZE)
.setDefaultInt ("max_instances_per_app", DEFAULT_MAX_INSTANCES_PER_APP)
.setDefaultInt ("pool_idle_time", DEFAULT_POOL_IDLE_TIME);
P_DEBUG("Starting Watchdog...");
try {
TRACE_POINT();
// Required options
passengerRoot = agentsOptions.get("passenger_root");
webServerPid = agentsOptions.getPid("web_server_pid");
// Optional options
UPDATE_TRACE_POINT();
tempDir = agentsOptions.get("temp_dir");
userSwitching = agentsOptions.getBool("user_switching");
defaultUser = agentsOptions.get("default_user");
if (!agentsOptions.has("default_group")) {
agentsOptions.set("default_group", inferDefaultGroup(defaultUser));
}
defaultGroup = agentsOptions.get("default_group");
webServerWorkerUid = agentsOptions.getUid("web_server_worker_uid");
webServerWorkerGid = agentsOptions.getGid("web_server_worker_gid");
UPDATE_TRACE_POINT();
randomGenerator = new RandomGenerator();
errorEvent = new EventFd();
UPDATE_TRACE_POINT();
serverInstanceDir.reset(new ServerInstanceDir(webServerPid, tempDir));
generation = serverInstanceDir->newGeneration(userSwitching, defaultUser,
defaultGroup, webServerWorkerUid, webServerWorkerGid);
agentsOptions.set("server_instance_dir", serverInstanceDir->getPath());
agentsOptions.setInt("generation_number", generation->getNumber());
UPDATE_TRACE_POINT();
ServerInstanceDirToucher serverInstanceDirToucher;
ResourceLocator resourceLocator(passengerRoot);
if (agentsOptions.get("analytics_server", false).empty()) {
// Using local, server instance specific logging agent.
loggingAgentAddress = "unix:" + generation->getPath() + "/logging.socket";
loggingAgentPassword = randomGenerator->generateAsciiString(64);
} else {
// Using remote logging agent.
loggingAgentAddress = agentsOptions.get("analytics_server");
}
UPDATE_TRACE_POINT();
shared_ptr<HelperAgentWatcher> helperAgentWatcher =
make_shared<HelperAgentWatcher>(resourceLocator);
shared_ptr<LoggingAgentWatcher> loggingAgentWatcher =
make_shared<LoggingAgentWatcher>(resourceLocator);
UPDATE_TRACE_POINT();
vector<AgentWatcherPtr> watchers;
vector<AgentWatcherPtr>::iterator it;
watchers.push_back(helperAgentWatcher);
if (agentsOptions.get("analytics_server", false).empty()) {
watchers.push_back(loggingAgentWatcher);
}
UPDATE_TRACE_POINT();
for (it = watchers.begin(); it != watchers.end(); it++) {
try {
(*it)->start();
} catch (const std::exception &e) {
writeArrayMessage(FEEDBACK_FD,
"Watchdog startup error",
e.what(),
NULL);
forceAllAgentsShutdown(watchers);
return 1;
}
// Allow other exceptions to propagate and crash the watchdog.
}
UPDATE_TRACE_POINT();
for (it = watchers.begin(); it != watchers.end(); it++) {
try {
(*it)->startWatching();
} catch (const std::exception &e) {
writeArrayMessage(FEEDBACK_FD,
"Watchdog startup error",
e.what(),
NULL);
forceAllAgentsShutdown(watchers);
return 1;
}
// Allow other exceptions to propagate and crash the watchdog.
}
UPDATE_TRACE_POINT();
writeArrayMessage(FEEDBACK_FD,
"Basic startup info",
serverInstanceDir->getPath().c_str(),
toString(generation->getNumber()).c_str(),
NULL);
UPDATE_TRACE_POINT();
for (it = watchers.begin(); it != watchers.end(); it++) {
(*it)->sendStartupInfo(FEEDBACK_FD);
}
UPDATE_TRACE_POINT();
writeArrayMessage(FEEDBACK_FD, "All agents started", NULL);
P_DEBUG("All Phusion Passenger agents started!");
this_thread::disable_interruption di;
this_thread::disable_syscall_interruption dsi;
UPDATE_TRACE_POINT();
bool exitGracefully = waitForStarterProcessOrWatchers(watchers);
if (exitGracefully) {
/* Fork a child process which cleans up all the agent processes in
* the background and exit this watchdog process so that we don't block
* the web server.
*/
P_DEBUG("Web server exited gracefully; gracefully shutting down all agents...");
} else {
P_DEBUG("Web server did not exit gracefully, forcing shutdown of all agents...");
}
UPDATE_TRACE_POINT();
AgentWatcher::stopWatching(watchers);
if (exitGracefully) {
UPDATE_TRACE_POINT();
cleanupAgentsInBackground(watchers);
return 0;
} else {
UPDATE_TRACE_POINT();
forceAllAgentsShutdown(watchers);
return 1;
}
} catch (const tracable_exception &e) {
P_ERROR(e.what() << "\n" << e.backtrace());
return 1;
} catch (const std::exception &e) {
P_ERROR(e.what());
return 1;
}
}
