Large refactoring of pt-agent to make the initial start up experience more reliable, i.e. just run and wait till a good config makes everything else work.

lib/Daemon.pm

@@ -34,44 +34,21 @@ sub new {
       log_file       => $args{log_file},
       pid_file       => $args{pid_file},
       daemonize      => $args{daemonize},
+      force_log_file => $args{force_log_file},
    };
    return bless $self, $class;
 }
 
 sub run {
-   my ($self, %args) = @_;
+   my ($self) = @_;
-   my $pid      ||= $PID;
-   my $pid_file ||= $self->{pid_file};
-   my $log_file ||= $self->{log_file};
 
-   if ( $self->{daemonize} ) {
+   # Just for brevity:
-      $self->_daemonize(
+   my $daemonize      = $self->{daemonize};
-         pid      => $pid,
+   my $pid_file       = $self->{pid_file};
-         pid_file => $pid_file,
+   my $log_file       = $self->{log_file};
-         log_file => $log_file,
+   my $force_log_file = $self->{force_log_file};
-      );
-   }
-   elsif ( $pid_file ) {
-      $self->_make_pid_file(
-         pid      => $pid,
-         pid_file => $pid_file,
-      );
-      $self->{pid_file_owner} = $pid;
-   }
-   else {
-      PTDEBUG && _d('Neither --daemonize nor --pid was specified');
-   }
 
-   return;
+   PTDEBUG && _d('Starting daemon');
-}
-
-sub _daemonize {
-   my ($self, %args) = @_;
-   my $pid      = $args{pid};
-   my $pid_file = $args{pid_file};
-   my $log_file = $args{log_file};
-
-   PTDEBUG && _d('Daemonizing');
 
    # First obtain the pid file or die trying.  NOTE: we're still the parent
    # so the pid file will contain the parent's pid at first.  This is done
@@ -82,27 +59,43 @@ sub _daemonize {
    if ( $pid_file ) {
       eval {
          $self->_make_pid_file(
-            pid      => $pid,  # parent's pid
+            pid      => $PID,  # parent's pid
             pid_file => $pid_file,
          );
       };
-      if ( $EVAL_ERROR ) {
+      die "$EVAL_ERROR\n" if $EVAL_ERROR;
-         die "Cannot daemonize: $EVAL_ERROR\n";
+      if ( !$daemonize ) {
+         # We're not going to daemonize, so mark the pid file as owned
+         # by the parent.  Otherwise, daemonize/fork and the child will
+         # take ownership.
+         $self->{pid_file_owner} = $PID;  # parent's pid
       }
    }
 
    # Fork, exit parent, continue as child process.
-   defined (my $child_pid = fork())
+   if ( $daemonize ) {
-      or die "Cannot fork: $OS_ERROR";
+      defined (my $child_pid = fork()) or die "Cannot fork: $OS_ERROR";
       if ( $child_pid ) {
          # I'm the parent.
          PTDEBUG && _d('Forked child', $child_pid);
          exit 0;
       }
  
-   # I'm the child.  First, open the log file, if any.  Do this first
+      # I'm the child. 
-   # so that all daemon/child output goes there.
+      POSIX::setsid() or die "Cannot start a new session: $OS_ERROR";
+      chdir '/'       or die "Cannot chdir to /: $OS_ERROR";
 
+      # Now update the pid file to contain the child's pid.
+      if ( $pid_file ) {
+         $self->_update_pid_file(
+            pid      => $PID,  # child's pid
+            pid_file => $pid_file,
+         );
+         $self->{pid_file_owner} = $PID;
+      }
+   }
+
+   if ( $daemonize || $force_log_file ) {
       # We used to only reopen STDIN to /dev/null if it's a tty because
       # otherwise it may be a pipe, in which case we didn't want to break
       # it.  However, Perl -t is not reliable.  This is true and false on
@@ -144,31 +137,12 @@ sub _daemonize {
                or die "Cannot reopen STDERR to /dev/null: $OS_ERROR";
          }
       }
-
-   # XXX: I don't think we need this?
-   # $OUTPUT_AUTOFLUSH = 1;
-
-   PTDEBUG && _d('I am child', $PID);
-
-   # Now update the pid file to contain the correct pid, i.e. the child's pid.
-   if ( $pid_file ) {
-      $self->_update_pid_file(
-         pid      => $PID,  # child's pid
-         pid_file => $pid_file,
-      );
-      $self->{pid_file_owner} = $PID;
    }
 
-   # Last: other misc daemon stuff.
+   PTDEBUG && _d('Daemon running');
-   POSIX::setsid() or die "Cannot start a new session: $OS_ERROR";
-   chdir '/'       or die "Cannot chdir to /: $OS_ERROR";
-
-   # We're not fully daemonized.
-
    return;
 }
 
-
 # Call this for non-daemonized scripts to make a PID file.
 sub _make_pid_file {
    my ($self, %args) = @_;