From 3f131e797d90d40147ba990af54770dd0058fc66 Mon Sep 17 00:00:00 2001
From: Bougyman <bougyman@rubyists.com>
Date: Tue, 3 May 2005 11:00:00 +0000
Subject: [PATCH] Allow spawn-fcgi in the foreground

Been looking for a clean way to spawn fastcgi listeners in the foreground and I
believe Trey has figured it out. This patch should take care of it by keeping
spawn-fcgi from losing track of the copied listening processes and allow full
supervison.

taken from http://rubyists.com/articles/2005/05/03/spawn-fcgi-in-the-foreground
---
 README.supervise    | 30 ++++++++++++++++++++++++++++++
 cgi-fcgi/cgi-fcgi.c | 45 ++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 68 insertions(+), 7 deletions(-)
 create mode 100644 README.supervise

diff --git a/README.supervise b/README.supervise
new file mode 100644
index 0000000..a1dbea5
--- /dev/null
+++ b/README.supervise
@@ -0,0 +1,30 @@
+To use, call your cgi-fcgi -start -connect $host:$port script with
+the -supervise option, like:
+
+cgi-fcgi -start -supervise -connect 127.0.0.1:1791 /path/to/dispatch.fcgi
+
+Full Supervise run script becomes
+
+    #!/bin/sh
+    RAIL_NUMBER=$(basename $PWD|awk -F'-' '{print $2}')
+    RAILS_HOST=$(<env/RAILS_HOST)
+    RAILS_ROOT=$(<env/RAILS_ROOT)
+    RAILS_PORT=179$RAIL_NUMBER
+    exec envdir ./env \
+      cgi-fcgi -supervise -start -connect \
+      $RAILS_HOST:$RAILS_PORT \
+      $RAILS_ROOT/public/dispatch.fcgi
+
+This would be in a script called ‘run’ in your ~/service/someapp-$RAIL_NUMBER
+directory, where $RAIL_NUMBER is 1-99. The references to ./env require a
+directory named ‘env’ to be set up in the same directory as the run script.
+This should have at least 3 files in it:
+
+RAILS_ROOT => contains one line that is the full path to your rails root directory.
+RAILS_ENV => contains one word, either ‘production’ or ‘development’
+RAILS_HOST => contains one IP address or FQDN
+
+You can set any other environment variables in this way by simply creating a
+file with the variable name and its contents will become the value of that
+environment variable. Because of the envdir ./env call before the cgi-fcgi
+call, your rails application has access to any variables set in this way.
diff --git a/cgi-fcgi/cgi-fcgi.c b/cgi-fcgi/cgi-fcgi.c
index ef6e71e..dd5146c 100644
--- a/cgi-fcgi/cgi-fcgi.c
+++ b/cgi-fcgi/cgi-fcgi.c
@@ -18,6 +18,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/wait.h>
+#include <signal.h>
 
 #include "fcgi_config.h"
 
@@ -582,7 +584,7 @@ static void FCGIUtil_BuildNameValueHeader(
 #define MAXARGS	16
 static int ParseArgs(int argc, char *argv[],
         int *doBindPtr, int *doStartPtr,
-        char *connectPathPtr, char *appPathPtr, int *nServersPtr) {
+        char *connectPathPtr, char *appPathPtr, int *nServersPtr, int *doDaemonPtr) {
     int	    i,
 	    x,
 	    err = 0,
@@ -598,6 +600,7 @@ static int ParseArgs(int argc, char *argv[],
     *connectPathPtr = '\0';
     *appPathPtr = '\0';
     *nServersPtr = 0;
+    *doDaemonPtr = TRUE;
 
     for(i = 0; i < MAXARGS; i++)
         av[i] = NULL;
@@ -649,7 +652,7 @@ static int ParseArgs(int argc, char *argv[],
 		}
 		fclose(fp);
 		err = ParseArgs(ac, av, doBindPtr, doStartPtr,
-                        connectPathPtr, appPathPtr, nServersPtr);
+                        connectPathPtr, appPathPtr, nServersPtr, doDaemonPtr);
 		for(x = 1; x < ac; x++) {
 		    ASSERT(av[x] != NULL);
 		    free(av[x]);
@@ -679,6 +682,8 @@ static int ParseArgs(int argc, char *argv[],
                 			MAXPATHLEN, argv[i]);
                 	err++;
             	}
+	    } else if(!strcmp(argv[i], "-supervise")) {
+		*doDaemonPtr = FALSE;
 	    } else {
 		fprintf(stderr, "Unknown option %s\n", argv[i]);
 		err++;
@@ -732,7 +737,16 @@ static int ParseArgs(int argc, char *argv[],
     }
     return err;
 }
-
+
+void handle_shutdown(int s)
+{
+    /* Kill our children processes */
+    signal(s, SIG_IGN);
+    kill(0, s);
+
+    exit(0);
+}
+
 int main(int argc, char **argv)
 {
     char **envp = environ;
@@ -742,20 +756,22 @@ int main(int argc, char **argv)
     int headerLen, valueLen;
     char *equalPtr;
     FCGI_BeginRequestRecord beginRecord;
-    int	doBind, doStart, nServers;
+    int	doBind, doStart, nServers, doDaemon;
     char appPath[MAXPATHLEN], bindPath[MAXPATHLEN];
+    int pid;
 
     if(ParseArgs(argc, argv, &doBind, &doStart,
-		   (char *) &bindPath, (char *) &appPath, &nServers)) {
+		   (char *) &bindPath, (char *) &appPath, &nServers, &doDaemon)) {
 	fprintf(stderr,
 "Usage:\n"
 "    cgi-fcgi -f <cmdPath> , or\n"
 "    cgi-fcgi -connect <connName> <appPath> [<nServers>] , or\n"
-"    cgi-fcgi -start -connect <connName> <appPath> [<nServers>] , or\n"
+"    cgi-fcgi -start -connect [-supervise] <connName> <appPath> [<nServers>] , or\n"
 "    cgi-fcgi -bind -connect <connName> ,\n"
 "where <connName> is either the pathname of a UNIX domain socket\n"
 "or (if -bind is given) a hostName:portNumber specification\n"
-"or (if -start is given) a :portNumber specification (uses local host).\n");
+"or (if -start is given) a :portNumber specification (uses local host).\n"
+"-supervise is for running with runit or daemontools.\n");
 	exit(1);
     }
 
@@ -771,12 +787,27 @@ int main(int argc, char **argv)
         bytesToRead = 0;
     }
 
+    /* Become a process group leader */
+    setsid();
+
+    /* Register our signal handler */
+    signal(SIGHUP, handle_shutdown);
+    signal(SIGINT, handle_shutdown);
+    signal(SIGTERM, handle_shutdown);
+
     if(doBind) {
         appServerSock = OS_FcgiConnect(bindPath);
     }
     if(doStart && (!doBind || appServerSock < 0)) {
         FCGI_Start(bindPath, appPath, nServers);
         if(!doBind) {
+            if(!doDaemon) {
+                for(pid=nServers; pid != 0; pid--) {
+                    wait(0);
+                }
+            }
+            signal(SIGTERM, SIG_IGN);
+            kill(0, SIGTERM);
             exit(0);
         } else {
             appServerSock = OS_FcgiConnect(bindPath);