dudki: initial import into svn repository

1 files changed, 244 insertions, 0 deletions

diff --git a/src/dudki.cc b/src/dudki.cc
new file mode 100644
index 0000000..3c50e56
--- a/dev/null
+++ b/src/dudki.cc
@@ -0,0 +1,244 @@
+#include <unistd.h>
+#include <signal.h>
+#include <syslog.h>
+#include <iostream>
+#include <fstream>
+#include <stdexcept>
+using namespace std;
+#include "configuration.h"
+#include "util.h"
+
+#include "config.h"
+#ifdef HAVE_GETOPT_H
+# include <getopt.h>
+#endif
+
+#ifndef DEFAULT_CONF_FILE
+# define DEFAULT_CONF_FILE "/etc/dudki.conf"
+#endif
+
+#define PHEADER PACKAGE " Version " VERSION
+#define PCOPY   "Copyright (c) 2004 Klever Group"
+
+bool finishing = false;
+static char **_argv = NULL;
+
+static void lethal_signal_handler(int signum) {
+    syslog(LOG_NOTICE,"Lethal signal received. Terminating.");
+    finishing = true;
+}
+static void sighup_handler(int signum) {
+    syslog(LOG_NOTICE,"SUGHUP received, reloading.");
+    execvp(_argv[0],_argv);
+}
+
+void check_herd(configuration& config) {
+    for(processes_t::iterator i=config.processes.begin();i!=config.processes.end();++i)
+	i->second.check(i->first,config);
+}
+
+void signal_self(const configuration& config,int signum) {
+    ifstream pids(config.pidfile.c_str(),ios::in);
+    if(!pids)
+	throw runtime_error("Can't detect running instance");
+    pid_t pid = 0;
+    pids >> pid;
+    if(!pid)
+	throw runtime_error("Can't detect running instance");
+    if(pid==getpid())
+	throw 0;
+    if(kill(pid,signum))
+	throw runtime_error("Failed to signal running instance");
+}
+
+int main(int argc,char **argv) {
+    try {
+	_argv = new char*[argc+1];
+	if(!_argv)
+	    throw runtime_error("memory allocation problem at the very start");
+	memmove(_argv,argv,sizeof(*_argv)*(argc+1));
+	string config_file = DEFAULT_CONF_FILE;
+	enum {
+	    op_default,
+	    op_work,
+	    op_hup,
+	    op_term,
+	    op_check,
+	    op_ensure,
+	    op_test
+	} op = op_default;
+	while(true) {
+#define	SHORTOPTSTRING "f:hVLrkcet"
+#ifdef HAVE_GETOPT_LONG
+	    static struct option opts[] = {
+		{ "help", no_argument, 0, 'h' },
+		{ "usage", no_argument, 0, 'h' },
+		{ "version", no_argument, 0, 'V' },
+		{ "license", no_argument, 0, 'L' },
+		{ "config", required_argument, 0, 'f' },
+		{ "kill", no_argument, 0, 'k' },
+		{ "reload", no_argument, 0, 'r' },
+		{ "check", no_argument, 0, 'c' },
+		{ "ensure", no_argument, 0, 'e' },
+		{ "test", no_argument, 0, 't' },
+		{ NULL, 0, 0, 0 }
+	    };
+	    int c = getopt_long(argc,argv,SHORTOPTSTRING,opts,NULL);
+#else /* !HAVE_GETOPT_LONG */
+	    int c = getopt(argc,argv,SHORTOPTSTRING);
+#endif /* /HAVE_GETOPT_LONG */
+	    if(c==-1)
+		break;
+	    switch(c) {
+		case 'h':
+		    cerr << PHEADER << endl
+			<< PCOPY << endl << endl <<
+#ifdef HAVE_GETOPT_LONG
+			" -h, --help\n"
+			" --usage         display this text\n"
+			" -V, --version   display version number\n"
+			" -L, --license   show license\n"
+			" -f filename, --config=filename\n"
+			"                 specify the configuration file to use\n"
+			"\n"
+			" -k, --kill      stop running instance\n"
+			" -r, --reload    reload running instance (send SIGHUP)\n"
+			" -c, --check     check if dudki is running\n"
+			" -e, --ensure    ensure that dudki is running\n"
+			" -t, --test      test configuration file and exit"
+#else /* !HAVE_GETOPT_LONG */
+			" -h              display this text\n"
+			" -V              display version number\n"
+			" -L              show license\n"
+			" -f filename     specify the configuration file to use\n"
+			"\n"
+			" -k              stop running instance\n"
+			" -r              reload running instance (send SIGHUP)\n"
+			" -c              check if dudki is running\n"
+			" -e              ensure that dudki is running\n"
+			" -t              test configuration file and exit"
+#endif /* /HAVE_GETOPT_LONG */
+			<< endl;
+		    exit(0);
+		    break;
+		case 'V':
+		    cerr << VERSION << endl;
+		    exit(0);
+		    break;
+		case 'L':
+		    extern const char *COPYING;
+		    cerr << COPYING << endl;
+		    exit(0);
+		    break;
+		case 'f':
+		    config_file = optarg;
+		    break;
+		case 'k':
+		    if(op!=op_default) {
+			cerr << "Can't obey two or more orders at once" << endl;
+			exit(1);
+		    }
+		    op = op_term;
+		    break;
+		case 'r':
+		    if(op!=op_default) {
+			cerr << "Can't obey two or more orders at once" << endl;
+			exit(1);
+		    }
+		    op = op_hup;
+		    break;
+		case 'c':
+		    if(op!=op_default) {
+			cerr << "Can't obey two or more orders at once" << endl;
+			exit(1);
+		    }
+		    op = op_check;
+		    break;
+		case 'e':
+		    if(op!=op_default) {
+			cerr << "Can't obey two or more orders at once" << endl;
+			exit(1);
+		    }
+		    op = op_ensure;
+		    break;
+		case 't':
+		    if(op!=op_default) {
+			cerr << "Can't obey two or more orders at once" << endl;
+			exit(1);
+		    }
+		    op = op_test;
+		    break;
+		default:
+		    cerr << "Huh??" << endl;
+		    exit(1);
+		    break;
+	    }
+	}
+	const char *sid = *argv;
+	const char *t;
+	while(t = index(sid,'/')) {
+	    sid = t; sid++;
+	}
+	openlog(sid,LOG_CONS|LOG_PERROR|LOG_PID,LOG_DAEMON);
+	configuration config;
+	config.parse(config_file);
+	switch(op) {
+	    case op_test:
+		cerr << "Configuration OK" << endl;
+		break;
+	    case op_hup:
+		signal_self(config,SIGHUP);
+		break;
+	    case op_term:
+		signal_self(config,SIGTERM);
+		break;
+	    case op_check:
+		try{
+		    signal_self(config,0);
+		    exit(0);
+		}catch(exception& e) {
+		    exit(1);
+		}
+	    case op_ensure:
+		try {
+		    signal_self(config,0);
+		    break;
+		}catch(exception& e) {
+		    syslog(LOG_NOTICE,"The dudki process is down, taking its place");
+		    config.daemonize = true;
+		}catch(int zero) {
+		    // we throw zero in case we're ensuring that this very process is running.
+		    // we don't have to daemonize if we're daemonic.
+		    config.daemonize = false;
+		}
+	    case op_default:
+	    case op_work:
+		{
+		    if(config.daemonize) {
+			pid_t pf = fork();
+			if(pf<0)
+			    throw runtime_error(string(__PRETTY_FUNCTION__)+": failed to fork()");
+			if(pf) {
+			    _exit(0);
+			}
+		    }
+		    pid_file pidfile;
+		    pidfile.set(config.pidfile);
+		    signal(SIGINT,lethal_signal_handler);
+		    signal(SIGABRT,lethal_signal_handler);
+		    signal(SIGTERM,lethal_signal_handler);
+		    signal(SIGHUP,sighup_handler);
+		    while(!finishing) {
+			check_herd(config);
+			sleep(config.check_interval);
+		    }
+		}
+		break;
+	    default:
+		throw runtime_error(string(__PRETTY_FUNCTION__)+": internal error");
+	}
+    }catch(exception& e) {
+	cerr << "Oops: " << e.what() << endl;
+	return 1;
+    }
+}