Category Archives: Tomcat / jboss application server

Restrict access for tomcat application server from IP or hosts

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To restrict access to a standalone Tomcat instance by IP address


<Valve className="org.apache.catalina.valves.RemoteAddrValve" allow="127.0.0.1"/>





The above will restrict access to the surrounding Engine, Host, or Context element inTOMCAT_HOME/conf/server.xml. You may also specify a comma separated list of IP addresses instead of a single address.

If you want to deny access to one or more IP addresses, you would do something like this:




<Valve className="org.apache.catalina.valves.RemoteAddrValve" deny="127.0.0.1"/>




To restrict by host name:






<Valve className="org.apache.catalina.valves.RemoteHostValve" allow="yahoo.com"/>




You use the same allow or deny attributes and the RemoteHostValve class instead of RemoteAddrValve.

How to catch 500 error from error logs in apache

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A. Enable cgi for your apache. Add following.

1) LoadModule cgid_module modules/mod_cgid.so

2)

<Directory “/appl/apache2/cgi-bin”>

AllowOverride None

Options ExecCGI

Order allow,deny

Allow from all

</Directory>

3)

ScriptAlias /cgi-bin/ “/appl/apache2/cgi-bin/”

AddHandler cgi-script .cgi

ErrorDocument 413 /cgi-bin/error.cgi

4) Restart apache.

B. Set up the following python script to catch this error, send an email to admin and give the custome message to users.

/appl/apche/cgi-bin/error.cgi

chmod +x /appl/apache/cgi-bin/error.cgi

#!/usr/bin/python
import sys, os
SENDMAIL = “/usr/sbin/sendmail” # sendmail location
print “Content-Type: text/htmlnn”;
if (os.environ[“REDIRECT_STATUS”] == “413”) or (os.environ[“REDIRECT_STATUS”] == “500”):
stats = “<table border=1><tr><td>Variable</td><td>Value</td></tr>”
for name, value in os.environ.items():
stats += “<tr><td>%s</td><td>%s</td></tr>” % (name,value)
stats += “</table>”
sendmail_location = “/usr/sbin/sendmail” # sendmail location
p = os.popen(“%s -t” % “/usr/sbin/sendmail”, “w”)
p.write(“From: %sn” % “error-reporter@domain.com”)
p.write(“To: %sn” % “mail@domain.com”)
p.write(“Content-Type: text/htmln”)
p.write(“Subject: Error %s in accessing n” % os.environ[“REDIRECT_STATUS”])
p.write(“n”) # blank line separating headers from body
p.write(stats)
status = p.close()
”’print “<H3><center>Inconvenience Regretted.  Team has been notified of this issue</center></h3>””’
cookieclearjs=”””
<script language=’JavaScript’>
var todate = new Date ( );
todate.setTime ( todate.getTime() – 100000 );
var domain_url_del = window.location.href;
var domain_Name_url_del = domain_url_del.split(“http://”);
var domain_Name_temp_del = domain_Name_url_del[1].split(“/”);
var domain_Name_del = domain_Name_temp_del[0];
var cookieList = document.cookie.split(‘;’);
for(var i=0;i < cookieList.length;i++)
{
var name = cookieList[i];
if(name.indexOf(“MyLinks”)!=-1)
{
document.cookie = ”+name+’=; path=//APPLICATION/PATH; domain=.’ + domain_Name_del + ‘; expires=’ + todate.toGMTString();
document.cookie = ”+name+’=; path=//APPLICATION/PATH; domain=.’ + domain_Name_del + ‘; expires=’ + todate.toGMTString();
}
}
</script>
“””
print cookieclearjs
print “<script language=’JavaScript’>window.location=’%s'</script>” % os.environ[“REDIRECT_SCRIPT_URI”]
else:
print “<H3><center>What you are looking for, is not here</center></h3>”

Installing Apache 2.2.11 with Weblogic 10.3 on Ubuntu 9.04 64 bit

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This post takes you through the steps to install Apache 2.2.11 on Ubuntu 9.04 64 bit and make it work with Weblogic 10.3. The post walks through the steps that I followed, the problems that I faced and the solutions ( er..hacks) to get them resolved.

Installing Apache

  • Is simple do

sudo apt-get install apache2

If you want to build it from sources then follow these steps.

  • Once you have installed apache2 then the installation happens at the following locations in Ubuntu

Apache config files are in /etc/apache
Apache log files are in /var/log/apache
Apache libs are in /usr/lib/apache
Other files can be in /usr/share/apache, /var/lib/apache
executables in /usr/sbin apache and apache2ctl

  • Now to start apache execute the following

vhazrati@vhazrati-laptop:/usr/sbin$ sudo apache2ctl start

  • Note that the server is started as a root, else you might get the following error

(13)Permission denied: make_sock: could not bind to address 0.0.0.0:80
no listening sockets available, shutting down
Unable to open logs

You should be able to access the default page on http://localhost now and see It Works!

Now, Integrating with Weblogic


  • Download the apache plugins for weblogic 10.3 from the following location

http://download.oracle.com/otn/bea/weblogic/server103/server103_apacheplugins.zip

  • Unzip the contents and select the mod_wl_22.so file from the location

<apache-plugin-unzip-location>linux/x86_64

  • This file needs to be loaded the following location

/usr/lib/apache2/modules

  • to test whether the file is valid or not do ldd

vhazrati@vhazrati-laptop:/usr/lib/apache2/modules$ ldd mod_wl_22.so
linux-vdso.so.1 =>  (0×00007fff02ffe000)
libstdc++.so.5 => /usr/lib/libstdc++.so.5 (0×00007f5cfaaff000)
libm.so.6 => /lib/libm.so.6 (0×00007f5cfa87a000)
libgcc_s.so.1 => /lib/libgcc_s.so.1 (0×00007f5cfa661000)
libc.so.6 => /lib/libc.so.6 (0×00007f5cfa2ef000)
/lib64/ld-linux-x86-64.so.2 (0×00007f5cfafc5000)

  • You might notice that some file like in my case libstdc++.so.5 => was not found!

-bash-3.00$ ldd mod_wl_22.so
libstdc++.so.5 => not found
libm.so.6 => /lib64/tls/libm.so.6 (0×0000002a9572f000)
libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0×0000002a958b5000)
libc.so.6 => /lib64/tls/libc.so.6 (0×0000002a959c3000)
/lib64/ld-linux-x86-64.so.2 (0×000000552aaaa000)

  • Goto the synaptic package manager, search and install this file.
  • Now create a weblogic.load file with the following contents

LoadModule weblogic_module /usr/lib/apache2/modules/mod_wl_22.so

  • and put it at the following location

/etc/apache2/mods-enabled

  • You can also create a weblogic.conf file with the following contents at the same location

<Location /medrec>
SetHandler weblogic-handler
WebLogicHost 127.0.1.1
WebLogicPort 7011
</Location>

This would help in redirecting a request like http://localhost/medrec to the weblogic server running on 127.0.1.1 and at 7011 port with the application name medrec.

  • Restart Apache

vhazrati@vhazrati-laptop:/usr/sbin$ sudo apache2ctl restart

  • Check whether the weblogic_module has been loaded successfully or not

vhazrati@vhazrati-laptop:/usr/sbin$ apache2 -t -D DUMP_MODULES
apache2: Could not reliably determine the server’s fully qualified domain name, using 127.0.1.1 for ServerName
Loaded Modules:
core_module (static)
log_config_module (static)
logio_module (static)
mpm_worker_module (static)
http_module (static)
so_module (static)
alias_module (shared)
auth_basic_module (shared)
authn_file_module (shared)
authz_default_module (shared)
authz_groupfile_module (shared)
authz_host_module (shared)
authz_user_module (shared)
autoindex_module (shared)
cgid_module (shared)
deflate_module (shared)
dir_module (shared)
env_module (shared)
mime_module (shared)
negotiation_module (shared)
setenvif_module (shared)
status_module (shared)
weblogic_module (shared)

  • If you see the weblogic_module loaded fine then you have configured it correctly and can now access the application at

http://localhost/medrec/

  • To test whether the apache2.conf file is correct or not you can use

vhazrati@vhazrati-laptop:/usr/sbin$ apache2 -t
apache2: Could not reliably determine the server’s fully qualified domain name, using 127.0.1.1 for ServerName
Syntax OK

Other Potential Problem(s)

  • You may encounter the problem bad user name ${APACHE_RUN_USER}

this is because the value of ${APACHE_RUN_USER} is not getting picked up. Ideally it should be picked up from /etc/apache2/envvars

which has the following entries

# envvars – default environment variables for apache2ctl

# Since there is no sane way to get the parsed apache2 config in scripts, some
# settings are defined via environment variables and then used in apache2ctl,
# /etc/init.d/apache2, /etc/logrotate.d/apache2, etc.
export APACHE_RUN_USER=www-data
export APACHE_RUN_GROUP=www-data
export APACHE_PID_FILE=/var/run/apache2.pid

However, still in your case if these values are not picked up then goto the /etc/apache2/apache2.conf file and make the following changes

# These need to be set in /etc/apache2/envvars
# User ${APACHE_RUN_USER}
# Group ${APACHE_RUN_GROUP}
User www-data
Group www-data

  • The weblogic.load file is not read for some reason and hence the weblogic_module is not loaded

Make an entry in the httpd.conf file at the following location

/etc/apache2/httpd.conf

and enter the LoadModule and other configuration data in this file

LoadModule weblogic_module /usr/lib/apache2/modules/mod_wl_22.so

<Location /medrec>
SetHandler weblogic-handler
WebLogicHost 127.0.1.1
WebLogicPort 7011
</Location>

There is an entry in the apache2.conf file to include the httpd.conf file, hence the changes of httpd.conf would get loaded

# Include all the user configurations:
Include /etc/apache2/httpd.conf

How to check the installed mod_jk version

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2 ways you can do that.

1. Better approach is
# strings /PATH/TO/APACHE/modules/mod_jk.so |grep -i mod_jk
mod_jk.so
mod_jk.c
mod_jk/1.2.18 <-- There you go. 2. If you have that already installed then if you have enable mod_jk log then you can check from that log file or you can do http://Your_SERVER/ApplicationURL/SomeFOLDER/@#@#CS<>>$#$#$% You will get internal serever error over there at the bottom you will get the mod_jk version with apache version. e.g. Apache/2.0.59 (Unix) mod_jk/1.2.28