commit f54eddf494e474531e5af609bcc376037a918977
Author: Nathan Scott <nathans@redhat.com>
Date:   Tue Apr 26 14:32:59 2022 +1000

    pmdapostfix: harden against a not-yet-running postfix
    
    Ensure the postfix PMDA can start and service requests even
    if postfix is not yet started.

diff --git a/src/perl/PMDA/local.c b/src/perl/PMDA/local.c
index e223bde7a..33130bc5d 100644
--- a/src/perl/PMDA/local.c
+++ b/src/perl/PMDA/local.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012-2017 Red Hat.
+ * Copyright (c) 2012-2017,2022 Red Hat.
  * Copyright (c) 2008-2011 Aconex.  All Rights Reserved.
  * 
  * This program is free software; you can redistribute it and/or modify it
@@ -139,18 +139,15 @@ int
 local_tail(char *file, scalar_t *callback, int cookie)
 {
     int fd = open(file, O_RDONLY | O_NDELAY);
-    struct stat stats;
+    struct stat stats = {0};
     int me;
 
-    if (fd < 0) {
-	pmNotifyErr(LOG_ERR, "open failed (%s): %s", file, osstrerror());
-	exit(1);
-    }
-    if (fstat(fd, &stats) < 0) {
-	pmNotifyErr(LOG_ERR, "fstat failed (%s): %s", file, osstrerror());
-	exit(1);
-    }
-    lseek(fd, 0L, SEEK_END);
+    if (fd < 0)
+	pmNotifyErr(LOG_INFO, "open failed (%s): %s", file, osstrerror());
+    else if (fstat(fd, &stats) < 0)
+	pmNotifyErr(LOG_INFO, "fstat failed (%s): %s", file, osstrerror());
+    else 
+	lseek(fd, 0L, SEEK_END);
     me = local_file(FILE_TAIL, fd, callback, cookie);
     files[me].me.tail.path = strdup(file);
     files[me].me.tail.dev = stats.st_dev;
@@ -416,10 +413,11 @@ local_pmdaMain(pmdaInterface *self)
 	}
 
 	for (i = 0; i < nfiles; i++) {
-	    fd = files[i].fd;
 	    /* check for log rotation or host reconnection needed */
 	    if ((count % 10) == 0)	/* but only once every 10 */
 		local_connection(&files[i]);
+	    if ((fd = files[i].fd) < 0)
+		continue;
 	    if (files[i].type != FILE_TAIL && !(__pmFD_ISSET(fd, &readyfds)))
 		continue;
 	    offset = 0;
@@ -431,21 +429,16 @@ multiread:
 		     (oserror() == EAGAIN) ||
 		     (oserror() == EWOULDBLOCK)))
 		    continue;
-		if (files[i].type == FILE_SOCK) {
-		    close(files[i].fd);
-		    files[i].fd = -1;
-		    continue;
-		}
-		pmNotifyErr(LOG_ERR, "Data read error on %s: %s\n",
-				local_filetype(files[i].type), osstrerror());
-		exit(1);
+		close(files[i].fd);
+		files[i].fd = -1;
+		continue;
 	    }
 	    if (bytes == 0) {
 		if (files[i].type == FILE_TAIL)
 		    continue;
-		pmNotifyErr(LOG_ERR, "No data to read - %s may be closed\n",
-				local_filetype(files[i].type));
-		exit(1);
+		close(files[i].fd);
+		files[i].fd = -1;
+		continue;
 	    }
 	    /*
 	     * good read ... data up to buffer + offset + bytes is all OK
diff --git a/src/pmdas/postfix/pmdapostfix.pl b/src/pmdas/postfix/pmdapostfix.pl
index ac46816bc..d6d3f4d3a 100644
--- a/src/pmdas/postfix/pmdapostfix.pl
+++ b/src/pmdas/postfix/pmdapostfix.pl
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2012-2015 Red Hat.
+# Copyright (c) 2012-2015,2022 Red Hat.
 # Copyright (c) 2009-2010 Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
 #
 # This program is free software; you can redistribute it and/or modify it
@@ -56,8 +56,6 @@ my @postfix_received_dom = (
 		1 => 'smtp',
 	     );
 
-my $setup = defined($ENV{'PCP_PERL_PMNS'}) || defined($ENV{'PCP_PERL_DOMAIN'});
-
 sub postfix_do_refresh
 {
     QUEUE:
@@ -212,7 +210,7 @@ $logstats{"received"}{1} = 0;
 
 # Note:
 # Environment variables.
-# $PMDA_POSTFIX_QSHAPE: alternative executable qshape scrpipt (for QA)
+# $PMDA_POSTFIX_QSHAPE: alternative executable qshape script (for QA)
 #                       ... over-rides default and command line argument.
 #			... over-rides default arguments -b 10 -t $refresh
 # $PMDA_POSTFIX_REFRESH: alternative refresh rate (for QA)
@@ -228,7 +226,7 @@ if (defined($ENV{'PMDA_POSTFIX_QSHAPE'})) {
     $qshape = $ENV{'PMDA_POSTFIX_QSHAPE'};
     $qshape_args = '';
 }
-if (!$setup) { $pmda->log("qshape cmd: $qshape $qshape_args <qname>"); }
+unless (pmda_install()) { $pmda->log("qshape cmd: $qshape $qshape_args <qname>"); }
 
 if (defined($ENV{'PMDA_POSTFIX_REFRESH'})) { $refresh = $ENV{'PMDA_POSTFIX_REFRESH'}; }
 
@@ -238,12 +236,15 @@ foreach my $file ( @logfiles ) {
     }
 }
 if (defined($ENV{'PMDA_POSTFIX_LOG'})) { $logfile = $ENV{'PMDA_POSTFIX_LOG'}; } 
-unless(defined($logfile))
-{
-    $pmda->log("Fatal: No Postfix log file found in: @logfiles");
-    die 'No Postfix log file found';
+unless (pmda_install()) {
+    if (defined($logfile)) {
+	$pmda->log("logfile: $logfile");
+    } else {
+	$pmda->log("Warning: assuming logfile: $logfiles[0] as no Postfix log found yet from: @logfiles");
+    }
 }
-if (!$setup) { $pmda->log("logfile: $logfile"); }
+# set a good default if none found, before continuing
+unless (defined($logfile)) { $logfile = $logfiles[0]; }
 
 $pmda->add_indom($postfix_queues_indom, \@postfix_queues_dom, '', '');
 $pmda->add_indom($postfix_sent_indom, \@postfix_sent_dom, '', '');