Running DSpace on Apache HTTPD and Tomcat using the mod_jk connector

For some background on why you'd want to do this, and the principles behind
the configuration, see pages on Securing DSpace and Running DSpace on Standard Ports.

Note: These instructions are for Linux, and may be somewhat specific to Red Hat Enterprise Linux 3.2.3-52 and the following software versions (but hopefully they are still helpful for other distros)

• DSpace 1.3.x and above
• Apache HTTPD 2.0.46
• Tomcat 5.5.9

Anyone who has successfully set up

mod_jk

connector under different conditions should feel free to add their notes!

• Instructions for Gentoo Linux can be found at http://gentoo-wiki.com/index.php?title=HOWTO_Apache2_and_Tomcat5&redirect=no

Step 1 - Check if mod_jk is installed

Check to see if the

mod_jk

connector is installed. Most likely (at least on Red Hat), it should be in

/etc/httpd/modules/

. However, you can try to locate it using the following command:

<nowiki>
locate mod_jk
</nowiki>

If there is no response, then

mod_jk

is not installed. Otherwise, if it is installed, you can obviously skip the next step!

Step 2 - Install mod_jk from source

(1) Login as the root user. (or someone with "root"-like privileges)

(2) Before trying to build

mod_jk

, you must make sure you have the following pre-requisite programs installed (use the

which

command to check for each):

• libtool

  (ftp://ftp.gnu.org/gnu/libtool)

• autoconf

  (http://ftp.gnu.org/gnu/autoconf)

• ant

  (http://jakarta.apache.org/ant/)

  ant

  should already be installed (since it's necessary for DSpace). If

  libtool

  or

  autoconf

  are missing (both should be in

  /usr/bin

  ), download the source and compile using the following commands:
  <nowiki>
  ./configure
  make
  make install
  </nowiki>

(3) In addition, you must have the Apache Web Server development tools installed. A quick way to check for this is to check for the APache eXtenSion tool (

apxs

). It should probably be in

/usr/sbin

, if installed:

<nowiki>
which apxs
</nowiki>

If

apxs

is missing, you can use the following command in Red Hat to install the

httpd-devel

RPM as root (Other distros may need to find and install this RPM through other means):

<nowiki>
up2date -i httpd-devel
</nowiki>

(4) Download the latest

mod_jk

source from the Tomcat Download site http://jakarta.apache.org/site/downloads/downloads_tomcat.html.

(5) Unzip the contents into your home directory:

<nowiki>
gunzip -c jakarta-tomcat-connectors-1.2.14.1-src.tar.gz | tar -xvf -
</nowiki>

(6) Configure the connectors with the path to the

apxs

file on your system:

<nowiki>
cd jakarta-tomcat-connectors-1.2.14.1-src
cd jk/native
./configure --with-apxs=/usr/sbin/apxs
</nowiki>

(7) Build

mod_jk

with the following command:

<nowiki>
make
</nowiki>

(8) Assuming all went well, the

mod_jk.so

file will be created in the

apache-2.0

subdirectory. You need to copy this file to Apache's shared object files directory (e.g.

/etc/httpd/modules/

). From the same

jk/native

directory run the following:

<nowiki>
cp apache-2.0/mod_jk.so /etc/httpd/modules
</nowiki>

(9) In addition, copy the sample workers.properties file to the Apache configuration directory (e.g.

/etc/httpd/conf/

). Assuming you are still in the

jk/native

directory, run the following commands:

<nowiki>
cd ../conf
cp workers.properties /etc/httpd/conf
</nowiki>

Step 3 - Configure workers.properties

Once the

mod_jk

connector has been installed, you will have to configure Apache to use this connector to communicate with Tomcat. First, modify the existing

workers.properties

file (should be in

/etc/httpd/conf/

, or whereever you copied it to in Step 2 above):
You will need to modify the following Tomcat and Java home directories:

<nowiki>
workers.tomcat_home=tomcat
workers.java_home=java
</nowiki>

In addition, you may need to uncomment (and possibly change) the JVM for Unix:

<nowiki>

1. Unix - Sun VM or blackdown
   worker.inprocess.jvm_lib=$(workers.java_home)$(ps)jre$(ps)lib$(ps)i386$(ps)server$(ps)libjvm.so
   </nowiki>

Note: initially the path above was

java/jre/lib/i386/classic/libjvm.so

However, the correct path of the

libjvm.so

(at least for Red Hat) is

java/jre/lib/i386/'''server'''/libjvm.so

(i.e. "

server/libjvm.so

", not "

classic/libjvm.so

")

Step 4 - Configure mod_jk connector

Next, you need to create a configuration file for the

mod_jk

module (alternatively, you could just add the following configuration directly into your Apache

httpd.conf

. I just like to separate things out a bit). In the

/etc/httpd/conf.d/

directory (or whatever directory holds your external configuration files, which

httpd.conf

loads), create a file called

jk.conf

which has the following content (make sure to edit any paths so they are valid on your server!):

<nowiki>
#

1. Use the JK Module to connect to Tomcat Instance
   #
2. Load mod_jk module
   LoadModule jk_module modules/mod_jk.so

1. Where to find workers.properties
   JkWorkersFile /etc/httpd/conf/workers.properties

1. Where to put jk logs
   JkLogFile /var/log/httpd/mod_jk.log

1. Set the jk log level debug/error/info
   JkLogLevel info

1. Select the log format
   JkLogStampFormat "%a %b %d %H:%M:%S %Y "

1. JkOptions indicate to send SSL KEY SIZE,
   #JkOptions +ForwardKeySize +ForwardUICompat -ForwardDirectories
2. Found that these options were necessary with Apache 2.2:
   JkOptions +ForwardKeySize +ForwardUIEscaped +ForwardDirectories

1. JkRequestLogFormat set the request format
   JkRequestLogFormat "%w %V %T"

1. Send all requests for /dspace context to worker ajp13
2. Note: ajp13 is defined in workers.properties and
3. uses the AJP 1.3 Protocol
   JkMount /dspace/* ajp13

1. ... and ditto if you want OAI
   JkMount /dspace-oai/* ajp13

#For extra security, deny direct access to any WEB-INF and META-INF directories
<LocationMatch "/WEB-INF/">
AllowOverride None
Deny from all
</LocationMatch>

<LocationMatch "/META-INF/">
AllowOverride None
Deny from all
</LocationMatch>
</nowiki>

The big thing to pay attention to is the context which you specify in

JkMount

! If you specify

/dspace/*

, then only requests to

http://my-host-name/dspace/*

will be forwarded to Tomcat! However, if you specify

/*

, then all requests to

http://my-host-name/*

will be forwarded to Tomcat.

You can get a little tricky by doing something like:

<nowiki>

1. Send all requests for root context / to worker ajp13
2. Note: ajp13 is defined in workers.properties and
3. uses the AJP 1.3 Protocol
   JkMount /* ajp13

1. Use SetEnvIf to set "no-jk" when /cgi-bin/ is encountered.
2. This is necessary so that /cgi-bin/ scripts
3. are run in Apache (and not forwarded to Tomcat).
   SetEnvIf Request_URI "/cgi-bin/*" no-jk

1. Set "no-jk" for /anotherApp/ as well (so it is run from Apache)
   SetEnvIf Request_URI "/anotherApp/*" no-jk
   </nowiki>

Notice, first you specify that all requests should be forwarded to Tomcat. But, then for specific UI's you can specify to ignore

mod_jk

(using the

no-jk

environment variable). So, the above specifies that everything except paths matching

http://my-host-name/cgi-bin/*

or

http://my-host-name/anotherApp/*

are forwarded to Tomcat.

Step 5 - Configure Tomcat

Next, you need to take a look at the Tomcat

server.xml

configuration file (in the

/conf

subdirectory, whereever Tomcat is installed). Ensure that the following AJP 1.3 Connector is uncommented:

<nowiki>
<!-- Define an AJP 1.3 Connector on port 8009 -->
<Connector port="8009" UIEncoding="UTF-8" tomcatAuthentication="false"
enableLookups="false" redirectPort="8443" protocol="AJP/1.3" />
</nowiki>

Make sure that the

port

specified corresponds to the port you defined for the

ajp13

worker (this port number is defined in the

workers.properties

file, as shown above). In addition, make sure the

UIEncoding

is set to

UTF-8

, and

tomcatAuthentication

is set to

false

(assuming you want authentication taken care of in Apache rather than Tomcat). Finally, make sure you set the

redirectPort

to be the port that Tomcat is running on (usually either 8443, for HTTPS, or 8080, for HTTP).

Step 6 - Restart everything and Test!

Restart Tomcat and Apache!
Now, test the connection between Apache and Tomcat. You should now be able to get to DSpace whether you specify port 8080 (for Tomcat) or not. For example, the following URLs should bring you to the same DSpace (you may need to replace

localhost

with your server path):

• http://localhost:8080/dspace

• http://localhost/dspace

Hopefully everything works for you! If it doesn't, ask questions to the dspace-tech@lists.sourceforge.net DSpace-Tech mailing list. If you find any problems with the above instructions, feel free to edit and enhance them!