Merge pull request #539 from grooverdan/serverlog

--server-log enhancements for containers/pods/systemd journal

Author: jmrenouard

mysqltuner.pl

@@ -88,6 +88,7 @@ package main;
     "noprocess"      => 0,
     "dbstat"         => 0,
     "nodbstat"       => 0,
+    "server-log"     => '',
     "tbstat"         => 0,
     "notbstat"       => 0,
     "idxstat"        => 0,
@@ -133,6 +134,7 @@ package main;
     'sysstat',         'nosysstat',
     'pfstat',          'nopfstat',
     'idxstat',         'noidxstat',
+    'server-log=s',
   )
   or pod2usage(
     -exitval  => 1,
@@ -236,6 +238,9 @@ package main;
 my $cmd  = ( $opt{nocolor} == 0 ) ? "\e[1;32m[CMD]($me)" : "[CMD]($me)";
 my $end  = ( $opt{nocolor} == 0 ) ? "\e[0m"              : "";
 
+# Maximum lines of log output to read from end
+my $maxlines = 30000;
+
 # Checks for supported or EOL'ed MySQL versions
 my ( $mysqlvermajor, $mysqlverminor, $mysqlvermicro );
 
@@ -1242,7 +1247,8 @@ sub get_log_file_real_path {
 }
 
 sub log_file_recommendations {
-    $myvar{'log_error'} =
+    my $fh;
+    $myvar{'log_error'} = $opt{'server-log'} ||
       get_log_file_real_path( $myvar{'log_error'}, $myvar{'hostname'},
         $myvar{'datadir'} );
 
@@ -1251,39 +1257,54 @@ sub log_file_recommendations {
         badprint "log_error is set to $myvar{'log_error'} MT can't read stderr";
         return
     }
-    if ( -f "$myvar{'log_error'}" ) {
-        goodprint "Log file $myvar{'log_error'} exists";
+    elsif ( $myvar{'log_error'} =~ /^(docker|podman|kubectl):(.*)/ ) {
+        open( $fh, '-|', "$1 logs --tail=$maxlines '$2'" )
+            // die "Can't start $1 $!";
+        goodprint "Log from cloud` $myvar{'log_error'} exists";
     }
-    else {
-        badprint "Log file $myvar{'log_error'} doesn't exist";
-        return;
+    elsif ($myvar{'log_error'} =~ /^systemd:(.*)/ ) {
+        open( $fh, '-|', "journalctl -n $maxlines -b  -u '$1'" )
+            // die "Can't start journalctl $!";
+        goodprint "Log journal` $myvar{'log_error'} exists";
     }
-    infoprint "Log file: "
-      . $myvar{'log_error'} . "("
-      . hr_bytes_rnd( ( stat $myvar{'log_error'} )[7] ) . ")";
-
-    if ( -r "$myvar{'log_error'}" ) {
+    elsif ( -f "$myvar{'log_error'}" ) {
+        goodprint "Log file $myvar{'log_error'} exists";
+        my $size = ( stat $myvar{'log_error'} )[7];
+        infoprint "Log file: "
+          . $myvar{'log_error'} . "("
+          . hr_bytes_rnd( $size ) . ")";
+
+        if ( $size > 0 ) {
+            goodprint "Log file $myvar{'log_error'} is not empty";
+            if ( $size < 32 * 1024 * 1024 ) {
+                goodprint "Log file $myvar{'log_error'} is smaller than 32 Mb";
+            }
+            else {
+                badprint "Log file $myvar{'log_error'} is bigger than 32 Mb";
+                push @generalrec,
+                  $myvar{'log_error'}
+                  . " is > 32Mb, you should analyze why or implement a rotation log strategy such as logrotate!";
+            }
+        }
+        else {
+            infoprint
+"Log file $myvar{'log_error'} is empty. Assuming log-rotation. Use --server-log={file} for explicit file";
+            return;
+	}
+        if ( ! open( $fh, '<', $myvar{'log_error'} ) ) {
+            badprint "Log file $myvar{'log_error'} isn't readable.";
+            return;
+        }
         goodprint "Log file $myvar{'log_error'} is readable.";
-    }
-    else {
-        badprint "Log file $myvar{'log_error'} isn't readable.";
-        return;
-    }
-    if ( ( stat $myvar{'log_error'} )[7] > 0 ) {
-        goodprint "Log file $myvar{'log_error'} is not empty";
-    }
-    else {
-        badprint "Log file $myvar{'log_error'} is empty";
-    }
 
-    if ( ( stat $myvar{'log_error'} )[7] < 32 * 1024 * 1024 ) {
-        goodprint "Log file $myvar{'log_error'} is smaller than 32 Mb";
+	if ( $maxlines * 80 < $size ) {
+          seek( $fh, -$maxlines * 80, 2);
+	  <$fh> ; # discard line fragment
+	}
     }
     else {
-        badprint "Log file $myvar{'log_error'} is bigger than 32 Mb";
-        push @generalrec,
-          $myvar{'log_error'}
-          . " is > 32Mb, you should analyze why or implement a rotation log strategy such as logrotate!";
+        badprint "Log file $myvar{'log_error'} doesn't exist";
+        return;
     }
 
     my $numLi     = 0;
@@ -1292,9 +1313,6 @@ sub log_file_recommendations {
     my @lastShutdowns;
     my @lastStarts;
 
-    open( my $fh, '<', $myvar{'log_error'} )
-      or die "Can't open $myvar{'log_error'} for read: $!";
-
     while ( my $logLi = <$fh> ) {
         chomp $logLi;
         $numLi++;
@@ -6428,6 +6446,7 @@ =head1 CONNECTION AND AUTHENTICATION
  --mysqladmin <path>         Path to a custom mysqladmin executable
  --mysqlcmd <path>           Path to a custom mysql executable
  --defaults-file <path>      Path to a custom .my.cnf
+ --server-log <path>         Path to explict log file
 
 =head1 PERFORMANCE AND REPORTING OPTIONS