Allow configuration files to be placed outside the data directory.

Add new postgresql.conf variables to point to data, pg_hba.conf, and
pg_ident.conf files.

Needs more documentation.

src/backend/utils/misc/guc-file.l

@@ -4,7 +4,7 @@
  *
  * Copyright (c) 2000-2003, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/backend/utils/misc/guc-file.l,v 1.22 2004/05/26 15:07:38 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/misc/guc-file.l,v 1.23 2004/07/11 00:18:44 momjian Exp $
  */
 
 %{
@@ -129,43 +129,24 @@ free_name_value_list(struct name_value_pair * list)
  * function does not return if an error occurs. If an error occurs, no
  * values will be changed.
  */
-void
-ProcessConfigFile(GucContext context)
+static void
+ReadConfigFile(char *filename, GucContext context)
 {
 	int token, parse_state;
 	char *opt_name, *opt_value;
-	char *filename;
 	struct name_value_pair *item, *head, *tail;
 	int elevel;
 	FILE * fp;
 
-	Assert(context == PGC_POSTMASTER || context == PGC_BACKEND 
-		|| context == PGC_SIGHUP);
-	Assert(DataDir);
 	elevel = (context == PGC_SIGHUP) ? DEBUG4 : ERROR;
 
-	/*
-	 * Open file
-	 */
-	filename = malloc(strlen(DataDir) + strlen(CONFIG_FILENAME) + 2);
-	if (filename == NULL)
-	{
-		ereport(elevel,
-				(errcode(ERRCODE_OUT_OF_MEMORY),
-				 errmsg("out of memory")));
-		return;
-	}
-	sprintf(filename, "%s/" CONFIG_FILENAME, DataDir);
-
     fp = AllocateFile(filename, "r");
     if (!fp)
     {
 		free(filename);
-        /* File not found is fine */
-        if (errno != ENOENT)
-            ereport(elevel,
-					(errcode_for_file_access(),
-					 errmsg("could not open configuration file \"%s\": %m", CONFIG_FILENAME)));
+		ereport(elevel,
+			(errcode_for_file_access(),
+			 errmsg("could not open configuration file \"%s\": %m", filename)));
 		return;
     }
 
@@ -197,7 +178,8 @@ ProcessConfigFile(GucContext context)
                     token = yylex();
 
                 if (token != GUC_ID && token != GUC_STRING && 
-					token != GUC_INTEGER && token != GUC_REAL && 
+					token != GUC_INTEGER && 
+					token != GUC_REAL && 
 					token != GUC_UNQUOTED_STRING)
                     goto parse_error;
                 opt_value = strdup(yytext);
@@ -259,7 +241,6 @@ ProcessConfigFile(GucContext context)
         }
 
 	FreeFile(fp);
-	free(filename);
 
 	/*
 	 * Check if all options are valid
@@ -282,12 +263,11 @@ ProcessConfigFile(GucContext context)
 
  parse_error:
 	FreeFile(fp);
-	free(filename);
 	free_name_value_list(head);
 	ereport(elevel,
 			(errcode(ERRCODE_SYNTAX_ERROR),
 			 errmsg("syntax error in file \"%s\" line %u, near token \"%s\"", 
-					CONFIG_FILENAME, ConfigFileLineno, yytext)));
+					filename, ConfigFileLineno, yytext)));
 	return;
 
  out_of_memory:
@@ -300,6 +280,65 @@ ProcessConfigFile(GucContext context)
 	return;
 }
 
+/*
+ * Function to read and process the configuration file. The
+ * parameter indicates the context that the file is being read
+ * (postmaster startup, backend startup, or SIGHUP). All options
+ * mentioned in the configuration file are set to new values. This
+ * function does not return if an error occurs. If an error occurs, no
+ * values will be changed.
+ */
+void
+ProcessConfigFile(GucContext context)
+{
+	char *filename;
+
+	Assert(context == PGC_POSTMASTER || context == PGC_BACKEND || context == PGC_SIGHUP);
+
+	/* Added for explicit config file */
+	if (user_pgconfig)
+	{
+		struct stat sb;
+
+		if (stat(user_pgconfig, &sb) != 0)
+		{
+			int elevel = (context == PGC_SIGHUP) ? DEBUG3 : ERROR;
+			elog(elevel, "Configuration file \"%s\" does not exist", user_pgconfig);
+			return;
+		}
+
+		if (S_ISDIR(sb.st_mode))
+		{
+			/* This will cause a small one time memory leak
+			 * if the user also specifies hba_conf,
+			 * ident_conf, and data_dir
+			 */
+			filename = malloc(strlen(user_pgconfig) + strlen(CONFIG_FILENAME) + 2);
+			sprintf(filename, "%s/%s", user_pgconfig, CONFIG_FILENAME);
+			user_pgconfig_is_dir = true;
+		}
+		else
+			filename = strdup(user_pgconfig);	/* Use explicit file */
+	}
+	else
+	{
+		/* Use datadir for config */
+		filename = malloc(strlen(DataDir) + strlen(CONFIG_FILENAME) + 2);
+		sprintf(filename, "%s/%s", DataDir, CONFIG_FILENAME);
+	}
+
+	if (filename == NULL)
+	{
+		int elevel = (context == PGC_SIGHUP) ? DEBUG3 : ERROR;
+		elog(elevel, "out of memory");
+		return;
+	}
+
+	ReadConfigFile(filename, context);
+
+	free(filename);
+}
+
 
 
 /* ----------------

src/backend/utils/misc/guc.c

@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.213 2004/07/05 23:14:14 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.214 2004/07/11 00:18:44 momjian Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -57,6 +57,13 @@
 #include "utils/pg_locale.h"
 #include "pgstat.h"
 
+char *guc_pgdata;
+char *guc_hbafile;
+char *guc_identfile;
+char *external_pidfile;
+
+char *user_pgconfig = NULL;
+bool user_pgconfig_is_dir = false;
 
 #ifndef PG_KRB_SRVTAB
 #define PG_KRB_SRVTAB ""
@@ -107,6 +114,7 @@ static bool assign_stage_log_stats(bool newval, bool doit, GucSource source);
 static bool assign_log_stats(bool newval, bool doit, GucSource source);
 static bool assign_transaction_read_only(bool newval, bool doit, GucSource source);
 
+static void ReadConfigFile(char *filename, GucContext context);
 
 /*
  * Debugging options
@@ -1701,15 +1709,40 @@ static struct config_string ConfigureNamesString[] =
 		NULL, assign_custom_variable_classes, NULL
 	},
 
+	{
+		{"pgdata", PGC_POSTMASTER, 0, gettext_noop("Sets the location of the data directory"), NULL}, 
+		&guc_pgdata,
+		NULL, NULL, NULL
+	},
+
+	{
+		{"hba_conf", PGC_SIGHUP, 0, gettext_noop("Sets the location of the \"hba\" configuration file"), NULL}, 
+		&guc_hbafile,
+		NULL, NULL, NULL
+	},
+
+	{
+		{"ident_conf", PGC_SIGHUP, 0, gettext_noop("Sets the location of the \"ident\" configuration file"), NULL}, 
+		&guc_identfile,
+		NULL, NULL, NULL
+	},
+
+	{
+		{"external_pidfile", PGC_POSTMASTER, 0, gettext_noop("Writes the postmaster PID to the specified file"), NULL},
+		&external_pidfile,
+		NULL, NULL, NULL
+	},
+
 	/* End-of-list marker */
 	{
 		{NULL, 0, 0, NULL, NULL}, NULL, NULL, NULL, NULL
 	}
 };
 
+
 /******** end of options list ********/
 
-
+  
 /*
  * To allow continued support of obsolete names for GUC variables, we apply
  * the following mappings to any unrecognized name.  Note that an old name

src/backend/utils/misc/postgresql.conf.sample

@@ -21,6 +21,16 @@
 # "pg_ctl reload".
 
 
+#---------------------------------------------------------------------------
+# CONFIGURATION FILES
+#---------------------------------------------------------------------------
+
+# pgdata = '/usr/local/pgsql/data'		# use data in another directory
+# hba_conf = '/etc/pgsql/pg_hba.conf' 		# use hba info in another directory
+# ident_conf = '/etc/pgsql/pg_ident.conf'	# use ident info in another directory
+# external_pidfile= '/var/run/postgresql.pid'	# write an extra pid file
+
+
 #---------------------------------------------------------------------------
 # CONNECTIONS AND AUTHENTICATION
 #---------------------------------------------------------------------------