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foundationdb/fdbmonitor/fdbmonitor.cpp

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/*
* fdbmonitor.cpp
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <signal.h>
#include <stdio.h>
#ifndef _WIN32
#include <unistd.h>
#endif
#include <random>
#ifdef __linux__
#include <sys/prctl.h>
#endif
#include <sys/wait.h>
#ifdef __linux__
#include <sys/inotify.h>
#include <time.h>
#include <linux/limits.h>
#endif
#ifdef __APPLE__
#include <sys/event.h>
#include <mach/mach.h>
#include <mach/mach_time.h>
#endif
#include <sys/time.h>
#include <stdlib.h>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include <string>
#include <sstream>
#include <iterator>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <syslog.h>
#include <stdarg.h>
#include <pwd.h>
#include <grp.h>
#include "flow/SimpleOpt.h"
#include "SimpleIni.h"
#if defined(CMAKE_BUILD) || !defined(WIN32)
#include "versions.h"
#endif
#ifdef __linux__
typedef fd_set* fdb_fd_set;
#elif defined __APPLE__
typedef int fdb_fd_set;
#endif
#define CANONICAL_PATH_SEPARATOR '/'
void monitor_fd( fdb_fd_set list, int fd, int* maxfd, void* cmd ) {
#ifdef __linux__
FD_SET( fd, list );
if ( fd > *maxfd )
*maxfd = fd;
#elif defined __APPLE__
/* ignore maxfd */
struct kevent ev;
EV_SET( &ev, fd, EVFILT_READ, EV_ADD, 0, 0, cmd );
kevent( list, &ev, 1, NULL, 0, NULL ); // FIXME: check?
#endif
}
void unmonitor_fd( fdb_fd_set list, int fd ) {
#ifdef __linux__
FD_CLR( fd, list );
#elif defined __APPLE__
struct kevent ev;
EV_SET( &ev, fd, EVFILT_READ, EV_DELETE, 0, 0, NULL );
kevent( list, &ev, 1, NULL, 0, NULL ); // FIXME: check?
#endif
}
double get_cur_timestamp() {
struct tm tm_info;
struct timeval tv;
gettimeofday(&tv, NULL);
localtime_r(&tv.tv_sec, &tm_info);
return tv.tv_sec + 1e-6*tv.tv_usec;
}
enum Severity { SevDebug=5, SevInfo=10, SevWarn=20, SevWarnAlways=30, SevError=40 };
int severity_to_priority(Severity severity) {
switch(severity) {
case SevError:
return LOG_ERR;
case SevWarnAlways:
return LOG_WARNING;
case SevWarn:
return LOG_NOTICE;
case SevDebug:
return LOG_DEBUG;
case SevInfo:
default:
return LOG_INFO;
}
}
bool daemonize = false;
std::string logGroup = "default";
void vlog_process_msg(Severity severity, const char* process, const char* format, va_list args) {
if (daemonize) {
char buf[4096];
int len = vsnprintf( buf, 4096, format, args);
syslog(severity_to_priority(severity), "LogGroup=\"%s\" Process=\"%s\": %.*s", logGroup.c_str(), process, len, buf);
} else {
fprintf(stderr, "Time=\"%.6f\" Severity=\"%d\" LogGroup=\"%s\" Process=\"%s\": ", get_cur_timestamp(), (int)severity, logGroup.c_str(), process);
vfprintf(stderr, format, args);
}
}
void log_msg(Severity severity, const char* format, ...) {
va_list args;
va_start(args, format);
vlog_process_msg(severity, "fdbmonitor", format, args);
va_end(args);
}
void log_process_msg(Severity severity, const char* process, const char* format, ...) {
va_list args;
va_start(args, format);
vlog_process_msg(severity, process, format, args);
va_end(args);
}
void log_err(const char* func, int err, const char* format, ...) {
va_list args;
va_start(args, format);
char buf[4096];
int len = vsnprintf( buf, 4096, format, args );
log_msg( SevError, "%.*s (%s error %d: %s)\n", len, buf, func, err, strerror(err) );
va_end(args);
}
const char* get_value_multi(const CSimpleIni& ini, const char* key, ...) {
const char* ret = NULL;
const char* section = NULL;
va_list ap;
va_start(ap, key);
while (!ret && (section = va_arg(ap, const char *)))
ret = ini.GetValue(section, key, NULL);
va_end(ap);
return ret;
}
double timer() {
#if defined(__linux__)
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
return double(ts.tv_sec) + (ts.tv_nsec * 1e-9);
#elif defined(__APPLE__)
mach_timebase_info_data_t timebase_info;
mach_timebase_info(&timebase_info);
return ((mach_absolute_time() * timebase_info.numer) / timebase_info.denom) * 1e-9;
#else
#error Port me!
#endif
};
int randomInt(int min, int max) {
static std::random_device rd;
static std::mt19937 gen(rd());
std::uniform_int_distribution<> dis(min, max);
return dis(gen);
}
std::string joinPath(std::string const& directory, std::string const& filename) {
auto d = directory;
auto f = filename;
while (f.size() && (f[0] == '/' || f[0] == CANONICAL_PATH_SEPARATOR))
f = f.substr(1);
while (d.size() && (d.back() == '/' || d.back() == CANONICAL_PATH_SEPARATOR))
d = d.substr(0, d.size()-1);
return d + CANONICAL_PATH_SEPARATOR + f;
}
std::string abspath(std::string const& filename) {
// Returns an absolute path canonicalized to use only CANONICAL_PATH_SEPARATOR
char result[PATH_MAX];
auto r = realpath( filename.c_str(), result );
if (!r) {
if (errno == ENOENT) {
int sep = filename.find_last_of( CANONICAL_PATH_SEPARATOR );
if (sep != std::string::npos) {
return joinPath( abspath( filename.substr(0, sep) ), filename.substr(sep) );
}
else if (filename.find("~") == std::string::npos) {
return joinPath( abspath( "." ), filename );
}
}
log_err("realpath", errno, "Unable to get real path for %s", filename.c_str());
return "";
}
return std::string(r);
}
std::string parentDirectory(std::string const& filename) {
size_t sep = filename.find_last_of( CANONICAL_PATH_SEPARATOR );
if (sep == std::string::npos) {
return "";
}
return filename.substr(0, sep);
}
int mkdir(std::string const& directory) {
size_t sep = 0;
do {
sep = directory.find_first_of('/', sep + 1);
if ( mkdir( directory.substr(0, sep).c_str(), 0755 ) != 0 ) {
if (errno == EEXIST)
continue;
return -1;
}
} while (sep != std::string::npos && sep != directory.length() - 1);
return 0;
}
struct Command {
private:
std::vector<std::string> commands;
fdb_fd_set fds;
public:
const char** argv;
std::string section, ssection;
uint32_t initial_restart_delay;
uint32_t max_restart_delay;
double current_restart_delay;
double restart_backoff;
uint32_t restart_delay_reset_interval;
double last_start;
double fork_retry_time;
bool quiet;
const char *delete_envvars;
bool deconfigured;
bool kill_on_configuration_change;
// one pair for each of stdout and stderr
int pipes[2][2];
Command() : argv(NULL) { }
Command(const CSimpleIni& ini, std::string _section, uint64_t id, fdb_fd_set fds, int* maxfd) : section(_section), argv(NULL), fork_retry_time(-1), quiet(false), delete_envvars(NULL), fds(fds), deconfigured(false), kill_on_configuration_change(true) {
char _ssection[strlen(section.c_str()) + 22];
snprintf(_ssection, strlen(section.c_str()) + 22, "%s.%llu", section.c_str(), id);
ssection = _ssection;
for ( auto p : pipes ) {
if ( (pipe(p) == 0) ) {
monitor_fd( fds, p[0], maxfd, this );
} else {
log_err( "pipe", errno, "Unable to construct pipe for %s", ssection.c_str() );
p[0] = -1;
p[1] = -1;
}
}
CSimpleIniA::TNamesDepend keys, skeys, gkeys;
ini.GetAllKeys(section.c_str(), keys);
ini.GetAllKeys(ssection.c_str(), skeys);
ini.GetAllKeys("general", gkeys);
keys.splice(keys.end(), skeys, skeys.begin(), skeys.end());
keys.splice(keys.end(), gkeys, gkeys.begin(), gkeys.end());
keys.sort(CSimpleIniA::Entry::KeyOrder());
keys.unique( [](const CSimpleIniA::Entry& lhs, const CSimpleIniA::Entry& rhs) -> bool {
return !CSimpleIniA::Entry::KeyOrder()(lhs, rhs);
} );
last_start = 0;
char* endptr;
const char* rd = get_value_multi(ini, "restart_delay", ssection.c_str(), section.c_str(), "general", "fdbmonitor", NULL);
if (!rd) {
log_msg(SevError, "Unable to resolve restart delay for %s\n", ssection.c_str());
return;
}
else {
max_restart_delay = strtoul(rd, &endptr, 10);
if (*endptr != '\0') {
log_msg(SevError, "Unable to parse restart delay for %s\n", ssection.c_str());
return;
}
}
const char* mrd = get_value_multi(ini, "initial_restart_delay", ssection.c_str(), section.c_str(), "general", "fdbmonitor", NULL);
if (!mrd) {
initial_restart_delay = 0;
}
else {
initial_restart_delay = std::min<uint32_t>(max_restart_delay, strtoul(mrd, &endptr, 10));
if (*endptr != '\0') {
log_msg(SevError, "Unable to parse initial restart delay for %s\n", ssection.c_str());
return;
}
}
current_restart_delay = initial_restart_delay;
const char* rbo = get_value_multi(ini, "restart_backoff", ssection.c_str(), section.c_str(), "general", "fdbmonitor", NULL);
if(!rbo) {
restart_backoff = max_restart_delay;
}
else {
restart_backoff = strtod(rbo, &endptr);
if (*endptr != '\0') {
log_msg(SevError, "Unable to parse restart backoff for %s\n", ssection.c_str());
return;
}
if (restart_backoff < 1.0) {
log_msg(SevError, "Invalid restart backoff value %lf for %s\n", restart_backoff, ssection.c_str());
return;
}
}
const char* rdri = get_value_multi(ini, "restart_delay_reset_interval", ssection.c_str(), section.c_str(), "general", "fdbmonitor", NULL);
if (!rdri) {
restart_delay_reset_interval = max_restart_delay;
}
else {
restart_delay_reset_interval = strtoul(rdri, &endptr, 10);
if (*endptr != '\0') {
log_msg(SevError, "Unable to parse restart delay reset interval for %s\n", ssection.c_str());
return;
}
}
const char* q = get_value_multi(ini, "disable_lifecycle_logging", ssection.c_str(), section.c_str(), "general", NULL);
if (q && !strcmp(q, "true"))
quiet = true;
const char* del_env = get_value_multi(ini, "delete_envvars", ssection.c_str(), section.c_str(), "general", NULL);
delete_envvars = del_env;
const char* kocc = get_value_multi(ini, "kill_on_configuration_change", ssection.c_str(), section.c_str(), "general", NULL);
if(kocc && strcmp(kocc, "true")) {
kill_on_configuration_change = false;
}
const char* binary = get_value_multi(ini, "command", ssection.c_str(), section.c_str(), "general", NULL);
if (!binary) {
log_msg(SevError, "Unable to resolve command for %s\n", ssection.c_str());
return;
}
std::stringstream ss(binary);
std::copy(std::istream_iterator<std::string> (ss), std::istream_iterator<std::string>(), std::back_inserter<std::vector<std::string>>(commands));
const char* id_s = ssection.c_str() + strlen(section.c_str()) + 1;
for (auto i : keys) {
if (!strcmp(i.pItem, "command") || !strcmp(i.pItem, "restart_delay") || !strcmp(i.pItem, "initial_restart_delay") || !strcmp(i.pItem, "restart_backoff") ||
!strcmp(i.pItem, "restart_delay_reset_interval") || !strcmp(i.pItem, "disable_lifecycle_logging") || !strcmp(i.pItem, "delete_envvars") ||
!strcmp(i.pItem, "kill_on_configuration_change"))
{
continue;
}
std::string opt = get_value_multi(ini, i.pItem, ssection.c_str(), section.c_str(), "general", NULL);
std::size_t pos = 0;
while ((pos = opt.find("$ID", pos)) != opt.npos)
opt.replace(pos, 3, id_s, strlen(id_s));
const char *flagName = i.pItem + 5;
if(strncmp("flag_", i.pItem, 5) == 0 && strlen(flagName) > 0) {
if(opt == "true")
commands.push_back(std::string("--") + flagName);
else if(opt != "false") {
log_msg(SevError, "Bad flag value, must be true/false. Flag: '%s' Value: '%s'\n", flagName, opt.c_str());
return;
}
}
else
commands.push_back(std::string("--").append(i.pItem).append("=").append(opt));
}
argv = new const char* [commands.size() + 1];
int i = 0;
for (auto itr : commands) {
argv[i++] = strdup(itr.c_str());
}
argv[i] = NULL;
}
~Command() {
delete[] argv;
for ( auto p : pipes ) {
if ( p[0] >= 0 && p[1] >= 0 ) {
unmonitor_fd( fds, p[0] );
close( p[0] );
close( p[1] );
}
}
}
void update(const Command& other) {
quiet = other.quiet;
delete_envvars = other.delete_envvars;
initial_restart_delay = other.initial_restart_delay;
max_restart_delay = other.max_restart_delay;
restart_backoff = other.restart_backoff;
restart_delay_reset_interval = other.restart_delay_reset_interval;
deconfigured = other.deconfigured;
kill_on_configuration_change = other.kill_on_configuration_change;
current_restart_delay = std::min<double>(max_restart_delay, current_restart_delay);
current_restart_delay = std::max<double>(initial_restart_delay, current_restart_delay);
}
bool operator!=(const Command& rhs) {
if (rhs.commands.size() != commands.size())
return true;
for (size_t i = 0; i < commands.size(); i++) {
if (commands[i].compare(rhs.commands[i]) != 0)
return true;
}
return false;
}
int get_and_update_current_restart_delay() {
if(timer() - last_start >= restart_delay_reset_interval) {
current_restart_delay = initial_restart_delay;
}
int jitter = randomInt(floor(-0.1 * current_restart_delay), ceil(0.1 * current_restart_delay));
int delay = std::max<int>(0, round(current_restart_delay) + jitter);
current_restart_delay = std::min<double>(max_restart_delay, restart_backoff * std::max(1.0, current_restart_delay));
return delay;
}
};
std::unordered_map<uint64_t, Command*> id_command;
std::unordered_map<pid_t, uint64_t> pid_id;
std::unordered_map<uint64_t, pid_t> id_pid;
enum { OPT_CONFFILE, OPT_LOCKFILE, OPT_LOGGROUP, OPT_DAEMONIZE, OPT_HELP };
CSimpleOpt::SOption g_rgOptions[] = {
{ OPT_CONFFILE, "--conffile", SO_REQ_SEP },
{ OPT_LOCKFILE, "--lockfile", SO_REQ_SEP },
{ OPT_LOGGROUP, "--loggroup", SO_REQ_SEP },
{ OPT_DAEMONIZE, "--daemonize", SO_NONE },
{ OPT_HELP, "-?", SO_NONE },
{ OPT_HELP, "-h", SO_NONE },
{ OPT_HELP, "--help", SO_NONE },
SO_END_OF_OPTIONS
};
void start_process(Command* cmd, uint64_t id, uid_t uid, gid_t gid, int delay, sigset_t* mask) {
if (!cmd->argv)
return;
pid_t pid = fork();
if (pid < 0) { /* fork error */
cmd->last_start = timer();
int fork_delay = cmd->get_and_update_current_restart_delay();
cmd->fork_retry_time = cmd->last_start + fork_delay;
log_err("fork", errno, "Unable to fork new %s process, restarting %s in %d seconds", cmd->argv[0], cmd->ssection.c_str(), fork_delay);
return;
} else if (pid == 0) { /* we are the child */
/* remove signal handlers from parent */
signal(SIGHUP, SIG_DFL);
signal(SIGINT, SIG_DFL);
signal(SIGTERM, SIG_DFL);
/* All output in this block should be to stdout (for SevInfo messages) or stderr (for SevError messages) */
/* Using log_msg() or log_err() from the child will cause the logs to be written incorrectly */
dup2( cmd->pipes[0][1], fileno(stdout) );
dup2( cmd->pipes[1][1], fileno(stderr) );
if(cmd->delete_envvars != NULL && std::strlen(cmd->delete_envvars) > 0) {
std::string vars(cmd->delete_envvars);
size_t start = 0;
do {
size_t bound = vars.find(" ", start);
std::string var = vars.substr(start, bound - start);
fprintf(stdout, "Deleting parent environment variable: \'%s\'\n", var.c_str());
fflush(stdout);
if(unsetenv(var.c_str())) {
fprintf(stderr, "Unable to remove parent environment variable: %s (unsetenv error %d: %s)\n", var.c_str(), errno, strerror(errno));
exit(1);
}
start = bound;
while(vars[start] == ' ')
start++;
} while(start <= vars.length());
}
#ifdef __linux__
signal(SIGCHLD, SIG_DFL);
sigprocmask(SIG_SETMASK, mask, NULL);
/* death of our parent raises SIGHUP */
prctl(PR_SET_PDEATHSIG, SIGHUP);
if (getppid() == 1) /* parent already died before prctl */
exit(0);
#endif
if (delay)
while ((delay = sleep(delay)) > 0) {}
if (getegid() != gid)
if (setgid(gid) != 0) {
fprintf(stderr, "Unable to set GID to %d (setgid error %d: %s)\n", gid, errno, strerror(errno));
exit(1);
}
if (geteuid() != uid)
if (setuid(uid) != 0) {
fprintf(stderr, "Unable to set UID to %d (setuid error %d: %s)\n", uid, errno, strerror(errno));
exit(1);
}
#ifdef __linux__
/* death of our parent raises SIGHUP */
/* although not documented to this effect, setting uid/gid
appears to reset PDEATHSIG */
prctl(PR_SET_PDEATHSIG, SIGHUP);
if (getppid() == 1) /* parent already died before prctl */
exit(0);
#endif
if (!cmd->quiet) {
fprintf(stdout, "Launching %s (%d) for %s\n", cmd->argv[0], getpid(), cmd->ssection.c_str());
fflush(stdout);
}
execv(cmd->argv[0], (char* const*)cmd->argv);
fprintf(stderr, "Unable to launch %s for %s\n", cmd->argv[0], cmd->ssection.c_str());
_exit(0);
}
cmd->last_start = timer() + delay;
cmd->fork_retry_time = -1;
pid_id[pid] = id;
id_pid[id] = pid;
}
volatile int exit_signal = 0;
#ifdef __linux__
void signal_handler(int sig) {
if (sig > exit_signal)
exit_signal = sig;
}
#endif
volatile bool child_exited = false;
#ifdef __linux__
void child_handler(int sig) {
child_exited = true;
}
#endif
void print_usage(const char* name) {
printf(
"FoundationDB Process Monitor " FDB_VT_PACKAGE_NAME " (v" FDB_VT_VERSION ")\n"
"Usage: %s [OPTIONS]\n"
"\n"
" --conffile CONFFILE\n"
" The path of a file containing the connection string for the\n"
" FoundationDB cluster. The default is\n"
" `/etc/foundationdb/foundationdb.conf'.\n"
" --lockfile LOCKFILE\n"
" The path of the mutual exclusion file for this instance of\n"
" fdbmonitor. The default is `/var/run/fdbmonitor.pid'.\n"
" --loggroup LOGGROUP\n"
" Sets the 'LogGroup' field with the specified value for all\n"
" entries in the log output. The default log group is 'default'.\n"
" --daemonize Background the fdbmonitor process.\n"
" -h, --help Display this help and exit.\n", name);
}
bool argv_equal(const char** a1, const char** a2)
{
int i = 0;
while (a1[i] && a2[i]) {
if (strcmp(a1[i], a2[i]))
return false;
i++;
}
if (a1[i] != NULL || a2[i] != NULL)
return false;
return true;
}
void kill_process(uint64_t id, bool wait = true) {
pid_t pid = id_pid[id];
log_msg(SevInfo, "Killing process %d\n", pid);
kill(pid, SIGTERM);
if(wait) {
waitpid(pid, NULL, 0);
}
pid_id.erase(pid);
id_pid.erase(id);
}
void load_conf(const char* confpath, uid_t &uid, gid_t &gid, sigset_t* mask, fdb_fd_set rfds, int* maxfd)
{
log_msg(SevInfo, "Loading configuration %s\n", confpath);
CSimpleIniA ini;
ini.SetUnicode();
SI_Error err = ini.LoadFile(confpath);
bool loadedConf = err >= 0;
if (!loadedConf) {
log_msg(SevError, "Unable to load configuration file %s (SI_Error: %d, errno: %d)\n", confpath, err, errno);
}
if(loadedConf) {
uid_t _uid;
gid_t _gid;
const char* user = ini.GetValue("fdbmonitor", "user", NULL);
const char* group = ini.GetValue("fdbmonitor", "group", NULL);
if (user) {
errno = 0;
struct passwd* pw = getpwnam(user);
if (!pw) {
log_err( "getpwnam", errno, "Unable to lookup user %s", user );
return;
}
_uid = pw->pw_uid;
} else
_uid = geteuid();
if (group) {
errno = 0;
struct group* gr = getgrnam(group);
if (!gr) {
log_err( "getgrnam", errno, "Unable to lookup group %s", group );
return;
}
_gid = gr->gr_gid;
} else
_gid = getegid();
/* Any change to uid or gid requires the process to be restarted to take effect */
if (uid != _uid || gid != _gid) {
std::vector<uint64_t> kill_ids;
for (auto i : id_pid) {
if(id_command[i.first]->kill_on_configuration_change) {
kill_ids.push_back(i.first);
}
}
for (auto i : kill_ids) {
kill_process(i);
delete id_command[i];
id_command.erase(i);
}
}
uid = _uid;
gid = _gid;
}
std::list<uint64_t> kill_ids;
std::list<std::pair<uint64_t, Command*>> start_ids;
for (auto i : id_pid) {
if (!loadedConf || ini.GetSectionSize(id_command[i.first]->ssection.c_str()) == -1) {
/* Server on this port no longer configured; deconfigure it and kill it if required */
log_msg(SevInfo, "Deconfigured %s\n", id_command[i.first]->ssection.c_str());
id_command[i.first]->deconfigured = true;
if(id_command[i.first]->kill_on_configuration_change) {
kill_ids.push_back(i.first);
delete id_command[i.first];
id_command.erase(i.first);
}
} else {
Command* cmd = new Command(ini, id_command[i.first]->section, i.first, rfds, maxfd);
// If we just turned on 'kill_on_configuration_change', then kill the process to make sure we pick up any of its pending config changes
if (*(id_command[i.first]) != *cmd || (cmd->kill_on_configuration_change && !id_command[i.first]->kill_on_configuration_change)) {
log_msg(SevInfo, "Found new configuration for %s\n", id_command[i.first]->ssection.c_str());
delete id_command[i.first];
id_command[i.first] = cmd;
if(id_command[i.first]->kill_on_configuration_change) {
kill_ids.push_back(i.first);
start_ids.push_back(std::make_pair(i.first, cmd));
}
} else {
log_msg(SevInfo, "Updated configuration for %s\n", id_command[i.first]->ssection.c_str());
id_command[i.first]->update(*cmd);
delete cmd;
}
}
}
for (auto i : kill_ids)
kill_process(i);
for (auto i : start_ids) {
start_process(i.second, i.first, uid, gid, 0, mask);
}
/* We've handled deconfigured sections, now look for newly
configured sections */
if(loadedConf) {
CSimpleIniA::TNamesDepend sections;
ini.GetAllSections(sections);
for (auto i : sections) {
if (auto dot = strrchr(i.pItem, '.')) {
char* strtol_end;
uint64_t id = strtoull(dot + 1, &strtol_end, 10);
if (*strtol_end != '\0' || !(id > 0)) {
log_msg(SevError, "Found bogus id in %s\n", i.pItem);
} else {
if (!id_pid.count(id)) {
/* Found something we haven't yet started */
Command *cmd;
auto itr = id_command.find(id);
if(itr != id_command.end()) {
cmd = itr->second;
}
else {
std::string section(i.pItem, dot - i.pItem);
cmd = new Command(ini, section, id, rfds, maxfd);
id_command[id] = cmd;
}
if(cmd->fork_retry_time <= timer()) {
log_msg(SevInfo, "Starting %s\n", i.pItem);
start_process(cmd, id, uid, gid, 0, mask);
}
}
}
}
}
}
}
/* cmd->pipes[pipe_idx] *must* be ready to read without blocking */
void read_child_output( Command* cmd, int pipe_idx, fdb_fd_set fds ) {
char buf[4096];
int len = read( cmd->pipes[pipe_idx][0], buf, 4096 );
if ( len == -1 ) {
if ( errno != EINTR ) {
/* We shouldn't get EAGAIN or EWOULDBLOCK
here, and if it's not EINTR then all of
the other alternatives seem "bad". */
log_err( "read", errno, "Error while reading from %s, no longer logging output", cmd->ssection.c_str() );
unmonitor_fd( fds, cmd->pipes[pipe_idx][0] );
}
return;
}
// pipe_idx == 0 is stdout, pipe_idx == 1 is stderr
Severity priority = (pipe_idx == 0) ? SevInfo : SevError;
int start = 0;
for ( int i = 0; i < len; i++ ) {
if ( buf[i] == '\n' ) {
log_process_msg( priority, cmd->ssection.c_str(), "%.*s", i - start + 1, buf + start );
start = i + 1;
}
}
if ( start < len ) {
log_process_msg( priority, cmd->ssection.c_str(), "%.*s\n", len - start, buf + start );
}
}
#ifdef __APPLE__
void watch_conf_dir( int kq, int* confd_fd, std::string confdir ) {
struct kevent ev;
std::string original = confdir;
while(true) {
/* If already watching, drop it and close */
if ( *confd_fd >= 0 ) {
EV_SET( &ev, *confd_fd, EVFILT_VNODE, EV_DELETE, NOTE_WRITE, 0, NULL );
kevent( kq, &ev, 1, NULL, 0, NULL );
close( *confd_fd );
}
confdir = original;
std::string child = confdir;
/* Find the nearest existing ancestor */
while( (*confd_fd = open( confdir.c_str(), O_EVTONLY )) < 0 && errno == ENOENT ) {
child = confdir;
confdir = parentDirectory(confdir);
}
if ( *confd_fd >= 0 ) {
EV_SET( &ev, *confd_fd, EVFILT_VNODE, EV_ADD | EV_CLEAR, NOTE_WRITE, 0, NULL );
kevent( kq, &ev, 1, NULL, 0, NULL );
/* If our child appeared since we last tested it, start over from the beginning */
if ( confdir != child && (access(child.c_str(), F_OK) == 0 || errno != ENOENT) ) {
continue;
}
if(confdir != original) {
log_msg(SevInfo, "Watching parent directory of missing directory %s\n", child.c_str());
}
else {
log_msg(SevInfo, "Watching conf dir %s\n", confdir.c_str());
}
}
return;
}
}
void watch_conf_file( int kq, int* conff_fd, const char* confpath ) {
struct kevent ev;
/* If already watching, drop it and close */
if ( *conff_fd >= 0 ) {
EV_SET( &ev, *conff_fd, EVFILT_VNODE, EV_DELETE, NOTE_WRITE | NOTE_ATTRIB, 0, NULL );
kevent( kq, &ev, 1, NULL, 0, NULL );
close( *conff_fd );
}
/* Open and watch */
*conff_fd = open( confpath, O_EVTONLY );
if ( *conff_fd >= 0 ) {
EV_SET( &ev, *conff_fd, EVFILT_VNODE, EV_ADD | EV_CLEAR, NOTE_WRITE | NOTE_ATTRIB, 0, NULL );
kevent( kq, &ev, 1, NULL, 0, NULL );
}
}
#endif
#ifdef __linux__
int fdbmon_stat(const char *path, struct stat *path_stat, bool is_link) {
return is_link ? lstat(path, path_stat) : stat(path, path_stat);
}
/* Sets watches to track changes to all symlinks on a path.
* Also sets a watch on the last existing ancestor of a path if the full path doesn't exist. */
std::unordered_map<int, std::unordered_set<std::string>> set_watches(std::string path, int ifd) {
std::unordered_map<int, std::unordered_set<std::string>> additional_watch_wds;
struct stat path_stat;
if(path.size() < 2)
return additional_watch_wds;
int idx = 1;
bool exists = true;
/* Check each level of the path, setting a watch on any symlinks.
* Stop checking once we get to a part of the path that doesn't exist.
* If we encounter a non-existing path, watch the closest existing ancestor. */
while(idx != std::string::npos && exists) {
idx = path.find_first_of('/', idx+1);
std::string subpath = path.substr(0, idx);
int level = 0;
while(true) {
/* Check path existence */
int result = fdbmon_stat(subpath.c_str(), &path_stat, true);
if(result != 0) {
if(errno == ENOENT) {
exists = false;
}
else {
log_err("lstat", errno, "Unable to stat %s", path.c_str());
exit(1);
}
}
if(exists) {
/* Don't do anything for existing non-links */
if(!S_ISLNK(path_stat.st_mode)) {
break;
}
else if(level++ == 100) {
log_msg(SevError, "Too many nested symlinks in path %s\n", path.c_str());
exit(1);
}
}
std::string parent = parentDirectory(subpath);
/* Watch the parent directory of the current path for changes */
int wd = inotify_add_watch(ifd, parent.c_str(), IN_CREATE | IN_MOVED_TO);
if (wd < 0) {
log_err("inotify_add_watch", errno, "Unable to add watch to parent directory %s", parent.c_str());
exit(1);
}
if(exists) {
log_msg(SevInfo, "Watching parent directory of symlink %s (%d)\n", subpath.c_str(), wd);
additional_watch_wds[wd].insert(subpath.substr(parent.size()+1));
}
else {
/* If the subpath has appeared since we set the watch, we should cancel it and resume traversing the path */
int result = fdbmon_stat(subpath.c_str(), &path_stat, true);
if(result == 0 || errno != ENOENT) {
inotify_rm_watch(ifd, wd);
continue;
}
log_msg(SevInfo, "Watching parent directory of missing directory %s (%d)\n", subpath.c_str(), wd);
additional_watch_wds[wd].insert(subpath.substr(parent.size()+1));
break;
}
/* Follow the symlink */
char buf[PATH_MAX+1];
ssize_t len = readlink(subpath.c_str(), buf, PATH_MAX);
if(len < 0) {
log_err("readlink", errno, "Unable to follow symlink %s", subpath.c_str());
exit(1);
}
buf[len] = '\0';
if(buf[0] == '/') {
subpath = buf;
}
else {
subpath = joinPath(parent, buf);
}
}
}
return additional_watch_wds;
}
#endif
int main(int argc, char** argv) {
std::string lockfile = "/var/run/fdbmonitor.pid";
std::string _confpath = "/etc/foundationdb/foundationdb.conf";
std::vector<const char *> additional_watch_paths;
CSimpleOpt args(argc, argv, g_rgOptions, SO_O_NOERR);
while (args.Next()) {
if (args.LastError() == SO_SUCCESS) {
switch (args.OptionId()) {
case OPT_CONFFILE:
_confpath = args.OptionArg();
break;
case OPT_LOCKFILE:
lockfile = args.OptionArg();
break;
case OPT_LOGGROUP:
if(strchr(args.OptionArg(), '"') != NULL) {
log_msg(SevError, "Invalid log group '%s', cannot contain '\"'\n", args.OptionArg());
exit(1);
}
logGroup = args.OptionArg();
break;
case OPT_DAEMONIZE:
daemonize = true;
break;
case OPT_HELP:
print_usage(argv[0]);
exit(0);
}
} else {
print_usage(argv[0]);
exit(1);
}
}
log_msg(SevInfo, "Started FoundationDB Process Monitor " FDB_VT_PACKAGE_NAME " (v" FDB_VT_VERSION ")\n");
// Modify _confpath to be absolute for further traversals
if(!_confpath.empty() && _confpath[0] != '/') {
char buf[PATH_MAX];
if( !getcwd(buf, PATH_MAX) ) {
log_err("getcwd", errno, "Unable to get cwd");
exit(1);
}
_confpath = joinPath(buf, _confpath);
}
// Guaranteed (if non-NULL) to be an absolute path with no
// symbolic link, /./ or /../ components
const char *p = realpath(_confpath.c_str(), NULL);
if (!p) {
log_msg(SevError, "No configuration file at %s\n", _confpath.c_str());
exit(1);
}
std::string confpath = p;
// Will always succeed given an absolute path
std::string confdir = parentDirectory(confpath);
std::string conffile = confpath.substr(confdir.size()+1);
#ifdef __linux__
// Setup inotify
int ifd = inotify_init();
if (ifd < 0) {
log_err("inotify_init", errno, "Unable to initialize inotify");
exit(1);
}
int conffile_wd = -1;
int confdir_wd = -1;
std::unordered_map<int, std::unordered_set<std::string>> additional_watch_wds;
bool reload_additional_watches = true;
#endif
/* fds we're blocking on via pselect or kevent */
fdb_fd_set watched_fds;
/* only linux needs this, but... */
int maxfd = 0;
#ifdef __linux__
fd_set rfds;
watched_fds = &rfds;
FD_ZERO(&rfds);
FD_SET(ifd, &rfds);
maxfd = ifd;
int nfds = 0;
fd_set srfds;
#endif
CSimpleIniA* ini = NULL;
if (daemonize) {
#ifdef __APPLE__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
#endif
if (daemon(0, 0)) {
#ifdef __APPLE__
#pragma GCC diagnostic pop
#endif
log_err("daemon", errno, "Unable to daemonize");
exit(1);
}
/* open syslog connection immediately, to be inherited by
forked children */
openlog("fdbmonitor", LOG_PID | LOG_NDELAY, LOG_DAEMON);
signal(SIGTSTP, SIG_IGN);
signal(SIGTTOU, SIG_IGN);
signal(SIGTTIN, SIG_IGN);
/* new process group, no controlling terminal */
/* unchecked since the only failure indicates we're already a
process group leader */
setsid();
}
/* open and lock our lockfile for mutual exclusion */
std::string lockfileDir = parentDirectory(abspath(lockfile));
if(lockfileDir.size() == 0) {
log_msg(SevError, "Unable to determine parent directory of lockfile %s\n", lockfile.c_str());
exit(1);
}
if(mkdir(lockfileDir) < 0) {
log_err("mkdir", errno, "Unable to create parent directory for lockfile %s", lockfile.c_str());
exit(1);
}
int lockfile_fd = open(lockfile.c_str(), O_RDWR|O_CREAT, 0640);
if (lockfile_fd < 0) {
log_err("open", errno, "Unable to open fdbmonitor lockfile %s", lockfile.c_str());
exit(1);
}
if (lockf(lockfile_fd, F_LOCK, 0) < 0) {
log_err("lockf", errno, "Unable to lock fdbmonitor lockfile %s (is fdbmonitor already running?)", lockfile.c_str());
exit(0);
}
if (chdir("/") < 0) {
log_err("chdir", errno, "Unable to change working directory");
exit(1);
}
/* write our pid to the lockfile for convenience */
char pid_buf[16];
snprintf(pid_buf, sizeof(pid_buf), "%d\n", getpid());
ssize_t ign = write(lockfile_fd, pid_buf, strlen(pid_buf));
#ifdef __linux__
/* attempt to do clean shutdown and remove lockfile when killed */
signal(SIGHUP, signal_handler);
signal(SIGINT, signal_handler);
signal(SIGTERM, signal_handler);
#elif defined(__APPLE__)
int kq = kqueue();
if ( kq < 0 ) {
log_err( "kqueue", errno, "Unable to create kqueue" );
exit(1);
}
watched_fds = kq;
signal(SIGHUP, SIG_IGN);
signal(SIGINT, SIG_IGN);
signal(SIGTERM, SIG_IGN);
struct kevent ev;
EV_SET( &ev, SIGHUP, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL);
kevent( kq, &ev, 1, NULL, 0, NULL );
EV_SET( &ev, SIGINT, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL);
kevent( kq, &ev, 1, NULL, 0, NULL );
EV_SET( &ev, SIGTERM, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL);
kevent( kq, &ev, 1, NULL, 0, NULL );
EV_SET( &ev, SIGCHLD, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL);
kevent( kq, &ev, 1, NULL, 0, NULL );
int confd_fd = -1;
int conff_fd = -1;
// Watch the directory holding the configuration file
watch_conf_dir( kq, &confd_fd, confdir );
#endif
#ifdef __linux__
signal(SIGCHLD, child_handler);
#endif
uid_t uid = 0;
gid_t gid = 0;
sigset_t normal_mask, full_mask;
sigfillset(&full_mask);
#ifdef __linux__
/* normal will be restored in our main loop in the call to
pselect, but none blocks all signals while processing events */
sigprocmask(SIG_SETMASK, &full_mask, &normal_mask);
#elif defined(__APPLE__)
sigprocmask(0, NULL, &normal_mask);
#endif
#ifdef __APPLE__
struct stat st_buf;
struct timespec mtimespec;
if (stat(confpath.c_str(), &st_buf) < 0) {
log_err("stat", errno, "Unable to stat configuration file %s", confpath.c_str());
}
memcpy(&mtimespec, &(st_buf.st_mtimespec), sizeof(struct timespec));
#endif
bool reload = true;
while (1) {
if (reload) {
reload = false;
#ifdef __linux__
/* Remove existing watches on conf file and directory */
if(confdir_wd >= 0 && inotify_rm_watch(ifd, confdir_wd) < 0) {
log_msg(SevInfo, "Could not remove inotify conf dir watch, continuing...\n");
}
if(conffile_wd >= 0 && inotify_rm_watch(ifd, conffile_wd) < 0) {
log_msg(SevInfo, "Could not remove inotify conf file watch, continuing...\n");
}
/* Create new watches */
conffile_wd = inotify_add_watch(ifd, confpath.c_str(), IN_CLOSE_WRITE);
if (conffile_wd < 0) {
if(errno != ENOENT) {
log_err("inotify_add_watch", errno, "Unable to set watch on configuration file %s", confpath.c_str());
exit(1);
}
else {
log_msg(SevInfo, "Conf file has been deleted %s\n", confpath.c_str());
}
} else {
log_msg(SevInfo, "Watching conf file %s\n", confpath.c_str());
}
confdir_wd = inotify_add_watch(ifd, confdir.c_str(), IN_CLOSE_WRITE | IN_MOVED_TO);
if (confdir_wd < 0) {
if(errno != ENOENT) {
log_err("inotify_add_watch", errno, "Unable to set watch on configuration file parent directory %s", confdir.c_str());
exit(1);
}
else {
reload_additional_watches = true;
log_msg(SevInfo, "Conf dir has been deleted %s\n", confdir.c_str());
}
} else {
log_msg(SevInfo, "Watching conf dir %s (%d)\n", confdir.c_str(), confdir_wd);
}
/* Reload watches on symlinks and/or the oldest existing ancestor */
if(reload_additional_watches) {
additional_watch_wds = set_watches(_confpath, ifd);
}
load_conf(confpath.c_str(), uid, gid, &normal_mask, &rfds, &maxfd);
reload_additional_watches = false;
#elif defined(__APPLE__)
load_conf( confpath.c_str(), uid, gid, &normal_mask, watched_fds, &maxfd );
watch_conf_file( kq, &conff_fd, confpath.c_str() );
watch_conf_dir( kq, &confd_fd, confdir );
#endif
}
double end_time = std::numeric_limits<double>::max();
for(auto i : id_command) {
if(i.second->fork_retry_time >= 0) {
end_time = std::min(i.second->fork_retry_time, end_time);
}
}
struct timespec tv;
double timeout = -1;
if(end_time < std::numeric_limits<double>::max()) {
timeout = std::max(0.0, end_time - timer());
if(timeout > 0) {
tv.tv_sec = timeout;
tv.tv_nsec = 1e9*(timeout-tv.tv_sec);
}
}
#ifdef __linux__
/* Block until something interesting happens (while atomically
unblocking signals) */
srfds = rfds;
nfds = 0;
if(timeout < 0) {
nfds = pselect(maxfd+1, &srfds, NULL, NULL, NULL, &normal_mask);
}
else if(timeout > 0) {
nfds = pselect(maxfd+1, &srfds, NULL, NULL, &tv, &normal_mask);
}
if(nfds == 0) {
reload = true;
}
#elif defined(__APPLE__)
int nev = 0;
if(timeout < 0) {
nev = kevent( kq, NULL, 0, &ev, 1, NULL );
}
else if(timeout > 0) {
nev = kevent( kq, NULL, 0, &ev, 1, &tv );
}
if(nev == 0) {
reload = true;
}
if (nev > 0) {
switch (ev.filter) {
case EVFILT_VNODE:
struct kevent timeout;
// This could be the conf dir or conf file
if ( ev.ident == confd_fd ) {
/* Changes in the directory holding the conf file; schedule a future timeout to reset watches and reload the conf */
EV_SET( &timeout, 1, EVFILT_TIMER, EV_ADD | EV_ONESHOT, 0, 200, NULL );
kevent( kq, &timeout, 1, NULL, 0, NULL );
} else {
/* Direct writes to the conf file; reload! */
reload = true;
}
break;
case EVFILT_TIMER:
reload = true;
break;
case EVFILT_SIGNAL:
switch (ev.ident) {
case SIGHUP:
case SIGINT:
case SIGTERM:
exit_signal = ev.ident;
break;
case SIGCHLD:
child_exited = true;
break;
default:
break;
}
break;
case EVFILT_READ:
Command* cmd = (Command*)ev.udata;
for ( int i = 0; i < 2 ; i++ ) {
if ( ev.ident == cmd->pipes[i][0] ) {
read_child_output( cmd, i, watched_fds );
}
}
break;
}
}
else {
reload = true;
}
#endif
/* select() could have returned because received an exit signal */
if (exit_signal > 0) {
switch(exit_signal) {
case SIGHUP:
for(auto i : id_command) {
i.second->current_restart_delay = i.second->initial_restart_delay;
i.second->fork_retry_time = -1;
}
reload = true;
log_msg(SevInfo, "Received signal %d (%s), resetting timeouts and reloading configuration\n", exit_signal, strsignal(exit_signal));
break;
case SIGINT:
case SIGTERM:
log_msg(SevWarn, "Received signal %d (%s), shutting down\n", exit_signal, strsignal(exit_signal));
/* Unblock signals */
signal(SIGCHLD, SIG_IGN);
sigprocmask(SIG_SETMASK, &normal_mask, NULL);
/* If daemonized, setsid() was called earlier so we can just kill our entire new process group */
if(daemonize) {
kill(0, SIGHUP);
}
else {
/* Otherwise kill each process individually but don't wait on them yet */
auto i = id_pid.begin();
auto iEnd = id_pid.end();
while(i != iEnd) {
// Must advance i before calling kill_process() which erases the entry at i
kill_process((i++)->first, false);
}
}
/* Wait for all child processes (says POSIX.1-2001) */
/* POSIX.1-2001 specifies that if the disposition of SIGCHLD is set to SIG_IGN, then children that terminate do not become zombies and a call to wait()
will block until all children have terminated, and then fail with errno set to ECHILD */
wait(NULL);
unlink(lockfile.c_str());
exit(0);
default:
break;
}
exit_signal = 0;
}
#ifdef __linux__
/* select() could have returned because we have a fd ready to
read (child output or inotify on conf file) */
if (nfds > 0) {
int len, i = 0;
char buf[4096];
for ( auto itr : id_command ) {
for ( int i = 0; i < 2; i++ ) {
if ( FD_ISSET( (itr.second)->pipes[i][0], &srfds ) ) {
read_child_output( itr.second, i, watched_fds );
}
}
}
if ( FD_ISSET( ifd, &srfds ) ) {
len = read(ifd, buf, 4096);
if (len < 0)
log_err("read", errno, "Error reading inotify message");
while (i < len) {
struct inotify_event* event = (struct inotify_event*) &buf[i];
auto search = additional_watch_wds.find(event->wd);
if(event->wd != conffile_wd) {
if(search != additional_watch_wds.end() && event->len && search->second.count(event->name)) {
log_msg(SevInfo, "Changes detected on watched symlink `%s': (%d, %#010x)\n", event->name, event->wd, event->mask);
char *redone_confpath = realpath(_confpath.c_str(), NULL);
if(!redone_confpath) {
log_msg(SevInfo, "Error calling realpath on `%s', continuing...\n", _confpath.c_str());
// exit(1);
i += sizeof(struct inotify_event) + event->len;
continue;
}
confpath = redone_confpath;
// Will always succeed given an absolute path
confdir = parentDirectory(confpath);
conffile = confpath.substr(confdir.size());
// Remove all the old watches
for(auto wd : additional_watch_wds) {
if(inotify_rm_watch(ifd, wd.first) < 0) {
// log_err("inotify_rm_watch", errno, "Unable to remove symlink watch %d", wd.first);
// exit(1);
log_msg(SevInfo, "Could not remove inotify watch %d, continuing...\n", wd.first);
}
}
reload = true;
reload_additional_watches = true;
break;
}
else if(event->wd == confdir_wd && event->len && conffile == event->name) {
reload = true;
}
}
else if (event->wd == conffile_wd) {
reload = true;
}
i += sizeof(struct inotify_event) + event->len;
}
}
}
#endif
/* select() could have returned because of one or more
SIGCHLDs */
if (child_exited) {
pid_t pid;
int child_status;
while ((pid = waitpid(-1, &child_status, WNOHANG))) {
if (pid < 0) {
if (errno != ECHILD)
log_err("waitpid", errno, "Error while waiting for child process");
break;
}
uint64_t id = pid_id[pid];
Command* cmd = id_command[id];
pid_id.erase(pid);
id_pid.erase(id);
if(cmd->deconfigured) {
delete cmd;
id_command.erase(id);
}
else {
int delay = cmd->get_and_update_current_restart_delay();
if (!cmd->quiet) {
if (WIFEXITED(child_status)) {
Severity priority = (WEXITSTATUS(child_status) == 0) ? SevWarn : SevError;
log_process_msg(priority, cmd->ssection.c_str(), "Process %d exited %d, restarting in %d seconds\n", pid, WEXITSTATUS(child_status), delay);
} else if (WIFSIGNALED(child_status))
log_process_msg(SevWarn, cmd->ssection.c_str(), "Process %d terminated by signal %d, restarting in %d seconds\n", pid, WTERMSIG(child_status), delay);
else
log_process_msg(SevWarnAlways, cmd->ssection.c_str(), "Process %d exited for unknown reason, restarting in %d seconds\n", pid, delay);
}
start_process(cmd, id, uid, gid, delay, &normal_mask);
}
}
child_exited = false;
}
}
}
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