Problems with modules for APACHE 2.4
lazarus / 38-Networking and Web Programming

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garlar27 · 2016-12-13 18:25

Hi,

I've have an Apache module which works fine with Apache 2.2 but I need
to use it in Apache 2.4.

I couldn't find much info of what to do.
After digging in the net and fiddling around the fpc.cfg and the code,
I could make it work just by changing the uses clause in the project.
Where said
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i uses ....,
httpd, fpapacheI changed it to
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i uses ....,
httpd24, fpapache24
Then finally Apache could load the module.

But when a request reaches the server, it doesn't responded.
Checking the Apache's error log I got the following message:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i An
unhandled exception occurred at $00007F3B31AFAA76:EHTTP: No
REQUEST_METHOD passed from server.  $00007F3B31AFAA76
Does any body knows what is going wrong?
Is there another thing I need to change in the project?


----
Lazarus 1.6.2 - FPC 3.0.0 -
Server: CentOS Linux 64 bits - Apache 2.4.6

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garlar27 · 2016-12-21 17:02

Well. Things got more complicated....
I have an old project (Apache module) which received a couple of files
(client send it through POST method) and saves them to disk.
Which worked good on Apache 2.2 (built with FPC 2.6.2).

Then I had to rebuild it to use it with Apache 2.4 (I used FPC 3.0.0).
But when a requirement was received this exception was raised
(extracted from the file "/var/log/httpd/error_log")
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i     An
unhandled exception occurred at $00007F3B31AFAA76:    EHTTP: No
REQUEST_METHOD passed from server.      $00007F3B31AFAA76
I added logs everywhere in the code to see where things went wrong.
But the only logs I got where the ones executed when the module was
loaded (the ones I put in the main block of the .lpr file).

Then I was curious so I recompile the project but this time for Apache
2.2 to see what it logged. And it logged a looooot more, but the
module was responding an error message, complaining about the fields
being empty.

So I recompiled the project with FPC 2.6.2 and every thing went back
to normal the module was responding correctly again. 

Then I went back again to the FPC 3.0.0 and added more logs to see
what the fields really had (I know I'm a little paranoid  ) and as the
error message said all the fields where empty....

A code extract:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i    //
...(ARequest: TRequest; AResponse: TResponse)   //   SERVER SIDE:
READING THE FIELDS...   AField1Value :=
trim(ARequest.QueryFields.Values['field1']);   if (Length(AField1Value
) = 0) then begin      AField1Value :=
trim(ARequest.ContentFields.Values['field1']);   end;   DLog('//   ###
  ('+_PROC_NAME+') - AField1Value: '+ AField1Value);//***   -=[DELETE
ME]=-   ***   ... 
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i    //  
CLIENT SIDE SENDING FILES...   HTTP          := THTTPSend.Create; 
 APostData     := TStringList.Create;   ...   APostData.Clear; 
 APostData.Add('field1='  + EncodeUrl(Trim(memField1.Lines.Text))    
          +'&field2=' + EncodeUrl(Trim(memField2.Lines.Text))        
      );    HTTP.Clear;   APostData.SaveToStream(HTTP.Document); 
 HTTP.MimeType := 'application/x-www-form-urlencoded';    if not
HTTP.HTTPMethod('POST', SomeURL) then begin      ...   end; In the
meantime I got this answer on a question I posted in another thread
which gives me more things to check:
Quote from: Leledumbo on December 21, 2016, 10:17:06 amQuote from:
garlar27 on December 19, 2016, 02:33:34 pmI've changed the units
"httpd" to "httpd24" and "fpapache" to "fpapache24" now the apache
server starts well. But when the request reaches the server it doesn't
responds. Checking the apache "error_log" file I read that the error
that occurred is

Quote    An unhandled exception occurred at $00007FF8F0760C66:
    EHTTP: No REQUEST_METHOD passed from server.
      $00007FF8F0760C66Googling the message "No REQUEST_METHOD passed
from server" points to FPC repositories only. For that reason I added
temporary logs everywhere to pin point if there is something wrong
with my code (which works fine on Apache 2.2) and the only logs I have
are the ones in the "begin ... end." of the ".lpr" file. It makes me
think that the exception is raised before my code has a chance to read
the request.
Something within apache virtual server config, I believe. I don't know
how apache pass environment variables to its modules, but the core of
fcl-web expects at least that environment variable to work.

I will try to do a small example project to post it here.
If I find something else I'll post it here. It might be use full for
someone else.

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garlar27 · 2016-12-26 19:59

Well, this is a short example of a web module and a client to send
requests.
I have the same errors described in the previous posts and I suspect
my problems come from a badly configured Apache server since the
module does not receives ANY thing even though the "Request" event is
fired.

I tested this example on a Virtual Box running Ubuntu 16.4 with a
fresh install of Apache 2.4.16
then I added the module mod_apache1.so with the appropriate
permissions and test it with the tester app and with Firefox (GET
method used) and had the same result. I didn't tested this example on
Apache 2.2 yet, but I guess it would work fine.

here is a brief explanation of the zip contents:

What's in the zip:
This example contains 2 projects:
   1- the Apache module (needs WebLaz).
   2- the tester app (needs synapse).
  
The Apache module was created using "Project/New Project" and picking
"Apache Module" from the list.

The tester app: I did my best to cover most of the things I needed and
things I wanted to try in a request. There's space to add new features
without messing the interface. WARNING there may be wrong captions in
labels and group boxes. Portions of the code where never used/tested
(though I believe it might work).


NOTE:
   I'm not a guru in HTTP neither in Apache installation and
programming (-_-'). I'm learning in the process of trying to solve the
problems...

EDIT: READ-ME.txt might be incomplete I forgot to save the content.
But the content is included in the lines above.

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mobilevil · 2017-08-07 10:06

hello,
I am seeing the same issue but have only started working on it since
yesterday. Did you make any progress?

I suspect the FPC apache module interface is wrong, or we are using
the wrong lib.