Re: [PATCH] pakfire.cgi: Implement logic to lock the page until pakfire has been fully launched.

[Bernhard Bitsch <bbitsch@ipfire.org>]

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Hello,

I can confirm this. Knowing about the issue allows to answer questions 
concerning it in the community.

-Bernhard

Am 10.11.2021 um 09:56 schrieb Michael Tremer:
> Hello,
> 
> I had a brief phone call with Stefan yesterday where he said that he was going to have a look at this again.
> 
> In the meantime he said that the patch can be shipped because it does not break anything, although it doesn’t solve the problem it was meant to solve either.
> 
> Can everybody confirm this?
> 
> -Michael
> 
>> On 5 Nov 2021, at 19:10, Jon Murphy <jcmurphy26(a)gmail.com> wrote:
>>
>> In Core Update 161 (testing):  Same issue.  I see the spin and Pakfire is working . . . but no messages.
>>
>> IPFire 2.27 (x86_64) - Core Update 161 Development Build: master/191347cc
>>
>> Jon
>>
>>
>>> On Oct 21, 2021, at 5:17 AM, Bernhard Bitsch <bbitsch(a)ipfire.org> wrote:
>>>
>>> Reviewed-by: Bernhard Bitsch <bbitsch(a)ipfire.org>
>>>
>>> The locking is functioning.
>>> But the excerpt of /var/log/messages isn't displayed.
>>>
>>> Am 18.10.2021 um 21:09 schrieb Stefan Schantl:
>>>> When performing any action which requires pakfire, the page gets locked
>>>> with an message informing the user that pakfire is working. The page
>>>> will be reloaded when pakfire has been launched and is doing the
>>>> requested operation - showing the well known log output. This also
>>>> happens when pakfire has been launched via any kind of terminal or SSH
>>>> session and the CGI gets accessed.
>>>> Internally before pakfire gets started a variable called page_lock will
>>>> be set to lock the page. An while loop will keep the page locked until
>>>> pakfire is launched fully and has written it's lock_file.
>>>> This approach will prevent us from any kind of required time intervall
>>>> or race conditions.
>>>> Signed-off-by: Stefan Schantl <stefan.schantl(a)ipfire.org>
>>>> ---
>>>>   html/cgi-bin/pakfire.cgi | 49 ++++++++++++++++++++++++++++++++++++++--
>>>>   1 file changed, 47 insertions(+), 2 deletions(-)
>>>> diff --git a/html/cgi-bin/pakfire.cgi b/html/cgi-bin/pakfire.cgi
>>>> index 0cf522ba1..f2381f031 100644
>>>> --- a/html/cgi-bin/pakfire.cgi
>>>> +++ b/html/cgi-bin/pakfire.cgi
>>>> @@ -44,6 +44,8 @@ $cgiparams{'VALID'} = '';
>>>>   $cgiparams{'INSPAKS'} = '';
>>>>   $cgiparams{'DELPAKS'} = '';
>>>>   +my $page_lock;
>>>> +
>>>>   sub refreshpage{&Header::openbox( 'Waiting', 1, "<meta http-equiv='refresh' content='1;'>" );print "<center><img src='/images/clock.gif' alt='' /><br/><font color='red'>$Lang::tr{'pagerefresh'}</font></center>";&Header::closebox();}
>>>>     &Header::getcgihash(\%cgiparams);
>>>> @@ -57,8 +59,9 @@ sub refreshpage{&Header::openbox( 'Waiting', 1, "<meta http-equiv='refresh' cont
>>>>   if (($cgiparams{'ACTION'} eq 'install') && (! -e $Pakfire::lockfile)) {
>>>>   	my @pkgs = split(/\|/, $cgiparams{'INSPAKS'});
>>>>   	if ("$cgiparams{'FORCE'}" eq "on") {
>>>> +		# Lock the page.
>>>> +		$page_lock = "1";
>>>>   		&General::system_background("/usr/local/bin/pakfire", "install", "--non-interactive", "--no-colors", @pkgs);
>>>> -		sleep(2);
>>>>   	} else {
>>>>   		&Header::openbox("100%", "center", $Lang::tr{'request'});
>>>>   		my @output = &General::system_output("/usr/local/bin/pakfire", "resolvedeps", "--no-colors", @pkgs);
>>>> @@ -95,8 +98,9 @@ END
>>>>   } elsif (($cgiparams{'ACTION'} eq 'remove') && (! -e $Pakfire::lockfile)) {
>>>>   	my @pkgs = split(/\|/, $cgiparams{'DELPAKS'});
>>>>   	if ("$cgiparams{'FORCE'}" eq "on") {
>>>> +		# Lock the page.
>>>> +		$page_lock = "1";
>>>>   		&General::system_background("/usr/local/bin/pakfire", "remove", "--non-interactive", "--no-colors", @pkgs);
>>>> -		sleep(2);
>>>>   	} else {
>>>>   		&Header::openbox("100%", "center", $Lang::tr{'request'});
>>>>   		my @output = &General::system_output("/usr/local/bin/pakfire", "resolvedeps", "--no-colors", @pkgs);
>>>> @@ -132,8 +136,12 @@ END
>>>>   	}
>>>>     } elsif (($cgiparams{'ACTION'} eq 'update') && (! -e $Pakfire::lockfile)) {
>>>> +	# Set variable to lock the page.
>>>> +	$page_lock = "1";
>>>>   	&General::system_background("/usr/local/bin/pakfire", "update", "--force", "--no-colors");
>>>>   } elsif (($cgiparams{'ACTION'} eq 'upgrade') && (!-e $Pakfire::lockfile)) {
>>>> +	# Lock the page.
>>>> +	$page_lock = "1";
>>>>   	&General::system_background("/usr/local/bin/pakfire", "upgrade", "-y", "--no-colors");
>>>>   } elsif ($cgiparams{'ACTION'} eq "$Lang::tr{'save'}") {
>>>>   	$pakfiresettings{"TREE"} = $cgiparams{"TREE"};
>>>> @@ -169,6 +177,43 @@ if ($errormessage) {
>>>>   	&Header::closebox();
>>>>   }
>>>>   +# Check if a page lock is required.
>>>> +if ($page_lock) {
>>>> +	&Header::openbox('Waiting', 1, ,);
>>>> +		print <<END;
>>>> +		<table>
>>>> +			<tr>
>>>> +				<td>
>>>> +					<img src='/images/indicator.gif' alt='$Lang::tr{'active'}' title='$Lang::tr{'active'}'>
>>>> +				</td>
>>>> +
>>>> +				<td>
>>>> +					$Lang::tr{'pakfire working'}
>>>> +				</td>
>>>> +			</tr>
>>>> +		</table>
>>>> +END
>>>> +	&Header::closebox();
>>>> +
>>>> +	# Infinite loop to lock the page until pakfire lockfile is present.
>>>> +	while($page_lock) {
>>>> +		unless (-e $Pakfire::lockfile) {
>>>> +			sleep(1);
>>>> +		} else {
>>>> +			# Release page lock.
>>>> +			undef($page_lock);
>>>> +
>>>> +			# Break loop.
>>>> +			last;
>>>> +		}
>>>> +	}
>>>> +
>>>> +	# Perform page reload.
>>>> +	print "<meta http-equiv='refresh' content='1;'>\n";
>>>> +	exit;
>>>> +}
>>>> +
>>>> +# Check if pakfire is already running. In this case a lockfile is present.
>>>>   if (-e $Pakfire::lockfile) {
>>>>   	&Header::openbox( 'Waiting', 1, "<meta http-equiv='refresh' content='10;'>" );
>>>>   	print <<END;
>>
>