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;