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APEX charts and reverse proxy (Houston we have a problem!!)

3643 Oct 2, 2007 2:29 AM

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Hi:

Every url html code generated by apex uses relative path, instead of absolute path. Every... i mean every except Charts :)
Apex charts puts absolute url on code [shame on this! :) ] ... look:

< param name="movie" value="/i/flashchart/2DPie.swf?XMLFile=http://195.32.2.3:8080/apex/apex_util.flash?p=100 ...

so Houston, we have a problem!

I am using Apache reverse proxy to access Apex, and as you may know, reverseproxy techniques are not html parsers, but only url handlers! So everytime i want to access a chart I have this pretty beautiful error inside the flash object:

XML loading failed: http://195.32.2.3:8080/apex/_blah_blah_blah :)

Anyone can help?

Best Regards,
Joao Oliveira

1. Re: APEX charts and reverse proxy (Houston we have a problem!!)

Jes Oct 2, 2007 2:40 AM (in response to 3643)

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Hi Joao,

Take a look at the following thread -

APEX Charts - Error XML Loading falied

John.
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2. Re: APEX charts and reverse proxy (Houston we have a problem!!)

3643 Oct 2, 2007 2:58 AM (in response to Jes)

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Hi Jes,

1st, Thanks for you answer. After reading it I am almost sure that this will work and solve the problem. but I have an answer...

Where do I put this lines:

PlsqlCGIEnvironmentList REQUEST_PROTOCOL=https
PlsqlCGIEnvironmentList HTTP_HOST=external-name:external-port

I can't find marvel.conf, neither dad.conf. I am using APEX without oracle http server installed, by using the database "gateway".

Best Regards
Joao Oliveira
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3. Re: APEX charts and reverse proxy (Houston we have a problem!!)

60660 Oct 2, 2007 6:00 AM (in response to 3643)

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After reading some of the solutions and documentation on apache2, I came up with this vhost configuration (still a bit of work-in-progress I'm afraid) under linux (APEX is set to its default port 8080):

yourdomain.conf[b]
<VirtualHost *:80> ServerName yourdomain SetEnv force-proxy-request-1.0 1 ProxyRequests Off ProxyHTMLExtended Off ProxyPreserveHost On ExtFilterDefine fixtext mode=output intype=text/html \ cmd="/bin/sed s/:8080//g" ProxyPass /apex http://localhost:8080/apex ProxyPass /i http://localhost:8080/i ProxyPass /sys http://localhost:8080/sys <Location /apex> ProxyPassReverse http://localhost:8080/apex SetOutputFilter fixtext </Location> <Location /i> ProxyPassReverse http://localhost:8080/apex SetOutputFilter fixtext </Location> <Location /sys> ProxyPassReverse http://localhost:8080/apex SetOutputFilter fixtext </Location> </VirtualHost>
One problem with this solution is the ExtFilter, which could replace any 8080 occurrence in the returend website, but at least the graphs in the demo app are working again.

C.

4. Re: APEX charts and reverse proxy (Houston we have a problem!!)

Jes Oct 2, 2007 6:18 AM (in response to 60660)
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What an imaginative solution ;) -

extFilterDefine fixtext mode=output intype=text/html \
cmd="/bin/sed s/:8080//g"
But (and I haven't tested this yet), wouldn't that have a potential issue in that it could remove the string 8080 that was passed as part of a regular APEX url (since you're not just searching for the port), e.g. -

http://apex.shellprompt.net/pls/apex/f?p=4550:1:8080042265718416
In this case it would remove the 8080 in the session?

To the OP, if you're using the Embedded PL/SQL gateway (I assume you're using XE or 11g, is that correct?), then you will need to look at the following document -

http://download.oracle.com/docs/cd/B19306_01/appdev.102/b14258/d_epg.htm

This shows you how you can make the equivalent setting for the DBMS_EPG.

Hope this helps,

John.
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5. Re: APEX charts and reverse proxy (Houston we have a problem!!)

60660 Oct 2, 2007 6:44 AM (in response to Jes)

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I don't think so, because the filter works on the returned document, not the URL. However, as I wrote, it could cause problems in replacing the 8080 value inside the document, for example in input/text fields.

C.
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6. Re: APEX charts and reverse proxy (Houston we have a problem!!)

Jes Oct 2, 2007 7:39 AM (in response to 60660)

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Sorry, bad example (on my part), the session id is also in the HTML of the returned document so I think it would modify it there too (and cause havoc/mischief).

John.
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7. Re: APEX charts and reverse proxy (Houston we have a problem!!)

60660 Oct 2, 2007 7:59 AM (in response to Jes)

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I haven't noticed that one yet, but if you say so, yes, there'll be a problem.

[Update]: Didn't know how often the session id is used. Time to take a closer look on sed and a more appropriate regular expression.

C.

Message was edited by:
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8. Re: APEX charts and reverse proxy (Houston we have a problem!!)

3643 Oct 3, 2007 6:53 AM (in response to Jes)

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Hi Jes,

Thanks for your answer! Yes we are using 11G. I suppose that the default dad name is 'APEX'. I've been exploring the dbms_epg package but i could not use the function to return the current value (as security measure before update it)

select dbms_epg.get_dad_attribute('APEX','cgi-environment-list')
from dual

This does not work...

Neither this:
select dbms_epg.get_dad_attribute('APEX','PlsqlCGIEnvironmentList')
from dual

Can you help on that?

Joao
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9. Re: APEX charts and reverse proxy (Houston we have a problem!!)

3643 Oct 12, 2007 6:08 AM (in response to 3643)

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can anyone help on this?
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10. Re: APEX charts and reverse proxy (Houston we have a problem!!)

3643 Oct 17, 2007 10:58 AM (in response to 3643)

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Hi:

Here it is what i tried:

BEGIN
DBMS_EPG.set_dad_attribute ('APEX',
'PlsqlCGIEnvironmentList',
'HTTP_HOST=www.myhost.pt:443'
);
END;

And the errors:

ORA-24232: o atributo do Gateway de PL/SQL Incorporado PlsqlCGIEnvironmentList é desconhecido
ORA-06512: na "SYS.DBMS_SYS_ERROR", linha 86
ORA-06512: na "SYS.DBMS_EPG", linha 101
ORA-06512: na "SYS.DBMS_EPG", linha 265
ORA-06512: na linha 2

And the translation:
ORA-24232: unknown Embedded PL/SQL Gateway attribute stringCause: The specified Embedded PL/SQL Gateway attribute was not known.

Can anyone help?

Best Regards,
Joao
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11. Re: APEX charts and reverse proxy (Houston we have a problem!!)

3643 Oct 17, 2007 11:19 AM (in response to 3643)

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Found it:

BEGIN
DBMS_EPG.set_dad_attribute ('APEX',
'cgi-environment-list',
'HTTP_HOST=www.myhost.pt:443'
);
END;

The name of the parameter is different in the embebbed gateway

Thanks
Joao
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12. Re: APEX charts and reverse proxy (Houston we have a problem!!)

Jes Oct 17, 2007 12:14 PM (in response to 3643)

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Hi,

If you look back at my previous message there's a link to the documentation that lists exactly which attribute you needed to use.

John.

---------------------------------------------
http://jes.blogs.shellprompt.net
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13. Re: APEX charts and reverse proxy (Houston we have a problem!!)

3643 Oct 18, 2007 7:32 AM (in response to Jes)

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Hi Jes,

I know, but i was trying to set the mod_plsql parameter... and the name of this parameter in the gateway is different from the one that we use to set in mod_plsql.

Anyway, thanks for you help. It was really profitable!

Joao
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14. Re: APEX charts and reverse proxy (Houston we have a problem!!)

494966 Jan 7, 2008 4:21 PM (in response to Jes)

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What an imaginative solution ;) -

extFilterDefine fixtext mode=output intype=text/html

\ 

cmd="/bin/sed s/:8080//g"  

pre]



But (and I haven't tested this yet), wouldn't that

have a potential issue in that it could remove the

string 8080 that was passed as part of a regular APEX

url (since you're not just searching for the port),

e.g. -



[pre]

http://apex.shellprompt.net/pls/apex/f?p=4550:1:808

0042265718416

I know this one is rather old, but changing
cmd="/bin/sed s/:8080//g"
to
cmd="/bin/sed s/:8080\//\//g"
should do the trick.
The expression searches for ":8080/" and replaces it with "/".

hth,
Moritz

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