[Webgate]: Configure ProxyPassMatch Directive -> Required for Apache/OHS Internal Redirect Calls

Potential Problem :

When webgate identifies an error/exception (may be reported by OAM) , in this
case webgate fires an internal redirect request for "/oberr.cgi" & this
invokes an error handler.
This error handler is defined in the webgate.conf file.
<Location "/oberr.cgi">
SetHandler obwebgateerr
</Location>

But when the resource webgate is the proxy. In this case if webgate
identifies error/exception, it fires an internal redirect request. But the
error handler "obwebgateerr" is not invoked.

Potential Reason: 

When apache sends the internal redirect request in that case it sets "proxy-server" handler by itself.
Due to which the handler defined for "/oberr.cgi" is not set as already an
handler is set. This causes the request to be proxied to the backend server &
causes problem.

Solution:

It is required to set a "ProxyPassMatch" directive before the "ProxyPass"
directive in the conf file.
By setting this directive, it will not proxy for the "/oberr.cgi" request to
the backend server rather it will be served by the webgate itself.

Configuration to do:

1) Add the following directive in the conf file. Restart the Web Server:

ProxyPassMatch ^/oberr.cgi !

Syntax:
ProxyPassMatch [regex] !

The ! directive is useful in situations where you don't want to reverse-proxy.

Eg:

ProxyPassMatch ^/oberr.cgi !
ProxyPass / http://something.com/AuthenticationService/
ProxyPassReverse / http://something.com/AuthenticationService/


Enjoy :-)

Creating an Oracle HTTP Server Instance

Let's Start the process.....

1) Go to the OHS Installed Directory.....

    bash$> cd $OHS_HOME


2) Move to opmn -> bin folder

    bash$> pwd
     bash$> /scratch/ckukreja/OHS/Oracle_WT1/
     bash$> cd opmn/bin


3) Now we will first create instance using the opmnctl executable.

bash$> ./opmnctl createinstance -oracleInstance /scratch/ckukreja/OHS/Oracle_WT1/instances/my_inst    -adminRegistration OFF

 Creating Oracle Instance directories...Done
 Recording OPMN ports reservations...Done
 Bootstrapping OPMN configuration files...Done
 Instantiating opmnctl for direct usage...Done
 Skipping instance registration
 Command succeeded.

Note: Here we have created a new instance name 'newInstance'. Also we have 'OFF' the 
         adminRegistration.

bash$> ls  /scratch/ckukreja/OHS/Oracle_WT1/instances/my_inst
auditlogs  bin  config  diagnostics  tmp


4) We have successfully created the instance, now it's time to create OHS Component.

 bash$> ./opmnctl createcomponent -componentType OHS -componentName myohs -oracleInstance 
                /scratch/ckukreja/OHS/Oracle_WT1/instances/my_inst

 Creating empty component directories...Done
 Provisioning OHS files for myohs
 Copying OHS files from ORACLE_HOME to ORACLE_INSTANCE locations
 Customizing httpd.conf
 Adding component's process control to OPMN...Done
 Skipping myohs component registration.
 Command succeeded.

Note: We have created 'myohs' OHS component with our instance 'my_inst'.

bash$> ls  /scratch/ckukreja/OHS/Oracle_WT1/instances/my_inst
auditlogs  bin  config  diagnostics  OHS  tmp


5) Now its time to start the OHS.

bash$> cd /scratch/ckukreja/OHS/Oracle_WT1/instances/my_inst/bin
bash$> ./opmnctl startall

bash$> ./opmnctl status

Processes in Instance: my_inst

 ---------------------------------+--------------------+---------+---------

 ias-component                    | process-type       |     pid | status

 ---------------------------------+--------------------+---------+---------

 myohs                           | OHS                |    7777 | Alive

We are done with the OHS Instance creation process...........!!!!!!!!!!!!!!!!


Enjoy :-)