Re: [pve-devel] [PATCH http-server 3/3] add debug log for problems during accept

[Thomas Lamprecht <t.lamprecht@proxmox.com>]

On 03.12.20 19:43, Stoiko Ivanov wrote:
> Co-Authored-by: Dominik Csapak <d.csapak@proxmox.com>
> Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
> ---
>  PVE/APIServer/AnyEvent.pm | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/PVE/APIServer/AnyEvent.pm b/PVE/APIServer/AnyEvent.pm
> index 7038b07..d33f6b0 100644
> --- a/PVE/APIServer/AnyEvent.pm
> +++ b/PVE/APIServer/AnyEvent.pm
> @@ -1520,6 +1520,11 @@ sub check_host_access {
>  
>      my $cip = Net::IP->new($clientip);
>  
> +    if (!$cip) {
> +	print "$$: check_host_access: clientip not parsable: $@\n" if $self->{debug};

I'd avoid using variable names 1:1 in log messages for such things, use "client IP"
(for not hard coding sub name see below)

> +	return 0;
> +    }
> +
>      my $match_allow = 0;
>      my $match_deny = 0;
>  
> @@ -1527,6 +1532,7 @@ sub check_host_access {
>  	foreach my $t (@{$self->{allow_from}}) {
>  	    if ($t->overlaps($cip)) {
>  		$match_allow = 1;
> +		print "$$: check_host_access: clientip allowed: ". $t->prefix() . "\n" if $self->{debug};
>  		last;
>  	    }
>  	}
> @@ -1535,6 +1541,7 @@ sub check_host_access {
>      if ($self->{deny_from}) {
>  	foreach my $t (@{$self->{deny_from}}) {
>  	    if ($t->overlaps($cip)) {
> +		print "$$: check_host_access: clientip denied: ". $t->prefix() . "\n" if $self->{debug};
>  		$match_deny = 1;
>  		last;
>  	    }
> @@ -1571,6 +1578,7 @@ sub accept_connections {
>  		my ($pfamily, $pport, $phost) = PVE::Tools::unpack_sockaddr_in46($sin);
>  		($reqstate->{peer_port}, $reqstate->{peer_host}) = ($pport,  Socket::inet_ntop($pfamily, $phost));
>  	    } else {
> +		print "$$: ACCEPT connection: getpeername failed: $!\n" if $self->{debug};
>  		shutdown($clientfh, 1);
>  		next;
>  	    }
> @@ -1619,6 +1627,7 @@ sub accept_connections {
>  
>      if (my $err = $@) {
>  	syslog('err', $err);
> +	print "$$: ACCEPT connection error: $err\n" if $self->{debug};
>  	shutdown($clientfh, 1) if $early_err;
>  	$self->{end_loop} = 1;
>      }
> 

can we use a helper method for the printing? Something along:

my sub dprintln {
    my ($line) = @_;
    return if !$self->{debug};
    print "worker[$$]: $line\n";
}

could maybe drop the worker prefix, but I'd say that all processes accepting connections
can be classified as workers..

If you want to get real fancy (I mean, for perl ;) you could use caller[0] to get some call
context to print.

    my ($pkg, $pkgfile, $line, $sub) = caller(1);

    print "worker[$$]: $sub: $line\n";

or even

    print "worker[$$]: $pkg +$line: $sub: $line\n";

We could later put such a helper in PVE::Tools and add to EXPORT_OK, could be helpful,
may want to add some bells n' whistels (control flags?) then - but that's out of scope
for this series.

[0]: https://perldoc.perl.org/functions/caller