processes specified by process names (pidof-like).

6 files changed, 120 insertions, 3 deletions

diff --git a/NEWS.xml b/NEWS.xml
index cd12d05..cc6085d 100644
--- a/NEWS.xml
+++ b/NEWS.xml
@@ -1,7 +1,8 @@
 <?xml version="1.0" encoding="us-ascii"?>
 <news>
- <version version="0.2" date="July 23rd, 2004">
+ <version version="0.2" date="July 24th, 2004">
   <ni>now dudki sends arbitrary signals to the processes being monitored from the command line</ni>
+  <ni>detection of running processes which do not keep pidfiles, using process name</ni>
  </version>
  <version version="0.1" date="July 21st, 2004">
   <ni><kbd>initgroups()</kbd> called before executing <kbd>RestartCommand</kbd></ni>
diff --git a/man/dudki.conf.5.in b/man/dudki.conf.5.in
index 23f636d..7d365d3 100644
--- a/man/dudki.conf.5.in
+++ b/man/dudki.conf.5.in
@@ -1,4 +1,4 @@
-.TH dudki.conf 5 "July 9th, 2004" "dudki.conf(5)" "Klever Group (http://www.klever.net/)"
+.TH dudki.conf 5 "July 24th, 2004" "dudki.conf(5)" "Klever Group (http://www.klever.net/)"
 .hla en
 
 .SH NAME
@@ -60,6 +60,10 @@ monitored from. The absence of file, as well as the absence of process
 specified by the pid stored in the file signifies the process death and
 triggers restart.
 .TP
+\fBProcessName\fR \fIprocess name\fR
+Specifies the name of the process. The alternative way to find process if it
+doesn't keep pid in the file. Similar to \fBpidof\fR(1).
+.TP
 \fBRestartCommand\fR \fIcommand\fR
 Specifies the command to run in order to restart the process.
 .TP
diff --git a/src/configuration.cc b/src/configuration.cc
index eb010c1..edc8c04 100644
--- a/src/configuration.cc
+++ b/src/configuration.cc
@@ -92,6 +92,10 @@ static DOTCONF_CB(dco__process) { dc_context *dcc = (dc_context*)ctx;
     return NULL;
 }
 
+static DOTCONF_CB(dco_process_name) { dc_context *dcc = (dc_context*)ctx;
+    dcc->ps->process_name = cmd->data.str;
+    return NULL;
+}
 static DOTCONF_CB(dco_restart_command) { dc_context *dcc = (dc_context*)ctx;
     dcc->ps->restart_cmd = cmd->data.str;
     return NULL;
@@ -116,6 +120,7 @@ static const configoption_t dc_options[] = {
     { "MailtoHeader", ARG_STR, dco_mailto_header, NULL, DCC_ROOT|DCC_PROCESS },
     { "Notify", ARG_STR, dco_notify, NULL, DCC_ROOT|DCC_PROCESS },
     { "<Process", ARG_STR, dco_process, NULL, DCC_ROOT },
+    {  "ProcessName", ARG_STR, dco_process_name, NULL, DCC_PROCESS },
     {  "RestartCommand", ARG_STR, dco_restart_command, NULL, DCC_PROCESS },
     {  "User", ARG_STR, dco_user, NULL, DCC_PROCESS },
     {  "Group", ARG_STR, dco_group, NULL, DCC_PROCESS },
diff --git a/src/dudki.cc b/src/dudki.cc
index 9562079..c966695 100644
--- a/src/dudki.cc
+++ b/src/dudki.cc
@@ -35,8 +35,10 @@ static void sighup_handler(int signum) {
 }
 
 void check_herd(configuration& config) {
+    process::prepare_herd();
     for(processes_t::iterator i=config.processes.begin();i!=config.processes.end();++i)
 	i->second.check(i->first,config);
+    process::unprepare_herd();
 }
 
 void signal_self(const configuration& config,int signum) {
@@ -220,7 +222,10 @@ int main(int argc,char **argv) {
 				processes_t::const_iterator i = config.processes.find(argv[narg]);
 				if(i==config.processes.end())
 				    throw runtime_error("no such process configured");
+				if(op_signum)
 				i->second.signal(op_signum);
+				else
+				    i->second.check();
 			    }catch(exception& e) {
 				cerr << "dudki(" << argv[narg] << "): " << e.what() << endl;
 				failures++;
diff --git a/src/process.cc b/src/process.cc
index 1ffac9f..8a5b5d2 100644
--- a/src/process.cc
+++ b/src/process.cc
@@ -4,19 +4,35 @@
 #include <signal.h>
 #include <pwd.h>
 #include <grp.h>
+#include <dirent.h>
 #include <sys/wait.h>
 #include <syslog.h>
 #include <errno.h>
 #include <iostream>
 #include <fstream>
+#include <sstream>
 #include <stdexcept>
+#include <string>
+#include <vector>
 using namespace std;
 #include "process.h"
 #include "configuration.h"
 
+static multimap<string,pid_t> procpids;
+
+void process::check() const {
+    if(!pidfile.empty()) {
+	signal(0);
+    }else if(!process_name.empty()) {
+	if(procpids.empty())
+	    gather_proc_info();
+	if(procpids.find(process_name)==procpids.end())
+	    throw runtime_error("no such process");
+    } // XXX: or else?
+}
 void process::check(const string& id,configuration& config) {
     try {
-	signal(0);
+	check();
 	patience = 0;
     }catch(exception& e) {
 	if(patience>60) { // TODO: configurable
@@ -176,6 +192,7 @@ void process::notify_mailto(const string& email,const string& id,const string& e
 }
 
 void process::signal(int signum) const {
+    if(!pidfile.empty()) {
     ifstream pids(pidfile.c_str(),ios::in);
     if(!pids)
 	throw runtime_error("no pidfile found");
@@ -186,4 +203,83 @@ void process::signal(int signum) const {
 	throw runtime_error("no pid in pidfile");
     if(kill(pid,signum))
 	throw runtime_error("failed to signal process");
+    }else if(!process_name.empty()) {
+	if(procpids.empty())
+	    gather_proc_info();
+	pair<multimap<string,pid_t>::const_iterator,multimap<string,pid_t>::const_iterator> range = procpids.equal_range(process_name);
+	int count = 0;
+	for(multimap<string,pid_t>::const_iterator i=range.first;i!=range.second;++i) {
+	    pid_t pid = i->second;
+	    if(kill(i->second,signum))
+		throw runtime_error("failed to signal process");
+	    count++;
+	}
+	if(!count)
+	    throw runtime_error("no running instance detected");
+    }else
+	throw runtime_error("nothing is known about the process");
+}
+
+void process::prepare_herd() {
+    procpids.clear();
+}
+void process::unprepare_herd() {
+    procpids.clear();
+}
+void process::gather_proc_info() {
+    vector<pid_t> allpids;
+    DIR *pd = opendir("/proc");
+    if(!pd)
+	throw runtime_error("failed to open /proc");
+    struct dirent *pde;
+    pid_t selfpid = getpid();
+    while(pde=readdir(pd)) {
+	errno=0;
+	pid_t pid = atoi(pde->d_name);
+	if((!pid) || pid==selfpid)
+	    continue;
+	allpids.push_back(pid);
+    }
+    closedir(pd);
+    char s[256];
+    procpids.clear();
+    for(vector<pid_t>::const_iterator i=allpids.begin();i!=allpids.end();++i) {
+	int r = snprintf(s,sizeof(s),"/proc/%d/stat",*i);
+	if(r>=sizeof(s) || r<1)
+	    continue;
+	string cmd;
+	ifstream ss(s,ios::in);
+	if(!ss)
+	    continue;
+	getline(ss,cmd);
+	string::size_type op = cmd.find('(');
+	if(op==string::npos)
+	    continue;
+	cmd.erase(0,op+1);
+	string::size_type cp = cmd.find(')');
+	if(cp==string::npos)
+	    continue;
+	cmd.erase(cp);
+	r = snprintf(s,sizeof(s),"/proc/%d/cmdline",*i);
+	if(r>=sizeof(s) || r<1)
+	    continue;
+	ifstream cs(s,ios::binary);
+	if(!cs)
+	    continue;
+	string command;
+	while(cs) {
+	    string cl;
+	    getline(cs,cl,(char)0);
+	    string::size_type lsl = cl.rfind('/');
+	    if(lsl!=string::npos)
+		cl.erase(0,lsl+1);
+	    if(cl.substr(0,cmd.length())==cmd) {
+		command = cl;
+		break;
+	    }
+	}
+	procpids.insert(pair<string,pid_t>(cmd,*i));
+	if((!command.empty()) && cmd!=command)
+	    procpids.insert(pair<string,pid_t>(command,*i));
+    }
 }
diff --git a/src/process.h b/src/process.h
index 27ee049..90b12d9 100644
--- a/src/process.h
+++ b/src/process.h
@@ -12,6 +12,7 @@ typedef map<string,string> headers_t;
 class process {
     public:
 	string pidfile;
+	string process_name;
 	string restart_cmd;
 	string notify;
 	string user;
@@ -31,6 +32,11 @@ class process {
 		const string& description,configuration& config);
 
 	void signal(int signum) const;
+	void check() const;
+
+	static void prepare_herd();
+	static void gather_proc_info();
+	static void unprepare_herd();
 };
 
 typedef map<string,process> processes_t;