Homework #2. Web Hosting using Name-based and IP-based Virtual Hosting, and MS VPC 2004 and User Mode Linux (UML) Virtual Machines.

• Apache Virtual Host documentation: http://cs.uccs.edu/manual/vhosts/
• The User-mode Linux Kernel Home Page: http://user-mode-linux.sourceforge.net/
• Microsoft VPC with link to evaluation user guide, http://www.microsoft.com/windows/virtualpc/evaluation/overview2004.mspx
• ISC BIND9. How to configure DNS.

Description:

• Login to EAS 138 PC with your ufp account.
• Donot click on the virtual pc icon on the desktop.
• Open the explore file browsing window and the c:\MyVirtualMachine\cs301\fc3cSis folder. Click on f3c3.vmc settting file.
• It will bring up the MS VPC window running Fedora Core 3 Linux virtual machine with label fc3c.
• Login to the fc3c virtual machine using root.
• Right click on the desktop to bring up a menu and select the first menu-item "open terminal". To release the cursor from the virtual machine, hit "Right-Alt". It allows mouse to move outside of VPC windows. It is important to remember this.
• Proceed to Exercises 1-2.

• We will create two name-based web host sites: ibm.com.csnet.uccs.edu and dell.com.csnet.uccs.edu, and one IP-based web host site: hp.com.csnet.uccs.edu using the apache 2.0.52 server on fc3c virtual machine.
• Both domain names maps to 10.10.10.1. Note that this is a Priviate LAN address and only valid in the virutal network connecting our virutal machines.
• Since the virtual machine is currently not allowed to communicate directly to Internet via network interface (for security reason), we can use either CD or floppy to import the data to the virtual machine or to export the data. Instead of using the physical media, the MS VPC supports the access of CD-ROM ISO image file or Floppy Disk Image (the access speed actually faster). I used a floppy image generation utility called FLOIMA created by w.guerrieri@teamsystem.com to generate a floppy image file called FLOPPY.IMG. It contains the named.conf, csnet.uccs.edu.zone, httpd.conf.txt files for the hw2 exercises. It is saved in http://cs.uccs.edu/~cs526/hw/hw2/FLOPPY.IMG for download.
• By using these files, it should avoid common typos and mistakes. While it speeds thing up, it is important that you understand the content in those files.
• Since we donot have access to gandalf.uccs.edu DNS server, we will set up a local name server on fc3c. Even though we can modify the /etc/hosts file to satisfy all name queries. It is more realistic to have DNS server involved in the process. The other reason is that the recent version of Apache will try to resolve the full qualified DNS name of the server and can refuse to startup if it does not get DNS response.
• Copy the DNS configuration and zone files, and httpd.conf files:
  • You can download the FLOPPY.IMG file from http://cs.uccs.edu/~cs526/hw/hw2/FLOPPY.IMG to a directory of the local host, says C:\VirtualMachines\lab138
  • Click the Floppy menu on MS VPC virtual machine and select "capature floppy disk image…" to choose the FLOPPY.IMG.
  • Once selected, you can go a terminal window of the fc3c virtual machine and type "mount /media/floppy" to mount the floppy drive.
  • The floppy content can then be accessed in /media/floppy directory.
• To setup the local DNS server, follow these steps:
  • cp /etc/named.conf /etc/named.conf.bak
    # back up the original named.conf file
  • cp /media/floppy/named.conf /etc
  • cp /media/floppy/csnet.uccs.edu.zone /var/named/chroot/var/named
  • cd /var/named
  • ln -s /var/named/chroot/var/named/csnet.uccs.edu.zone
    # fc3 use chroot to isolate/protect dns server
  • ifconfig eth1 10.10.10.1
  • service named start
    # This command start the named server
  • vi /etc/resolv.conf
  • Add "nameserver 10.10.10.1" line right after search command and make the local named server the primary name server.
  • nslookup ibm.com.csnet.uccs.edu
    to test if the name server is ok. It should indicate this domain name is associated with 10.10.10.1
  • If it does not return with IP address, try "service named restart" and let me know if it does not reply.
• To setup web server, follow these steps:
  • cd cp /etc/httpd/conf
  • cp httpd.conf httpd.conf.bak
  • cat httpd.conf /media/floppy/httpd.conf.txt > httpd.conf.new
    • httpd.conf.txt contains the following virtual hosting directives:
      
      NameVirtualHost 10.10.10.1:80
      <VirtualHost 10.10.10.1:80>
      ServerAdmin webmaster@ibm.com.csnet.uccs.edu
      DocumentRoot /var/www/html/ibm.com.csnet.uccs.edu
      ServerName ibm.com.csnet.uccs.edu
      ErrorLog logs/ibm.com.csnet.uccs.edu-error_log
      CustomLog logs/ibm.com.csnet.uccs.edu-access_log common
      </VirtualHost>
      <VirtualHost 10.10.10.1:80>
      ServerAdmin webmaster@fc3c.csnet.uccs.edu
      DocumentRoot /var/www/html/fc3c.csnet.uccs.edu
      ServerName fc3c.csnet.uccs.edu
      ErrorLog logs/fc3c.csnet.uccs.edu-error_log
      CustomLog logs/fc3c.csnet.uccs.edu-access_log common
      </VirtualHost>
      
      # the following for IP-based Web Hosting
      <VirtualHost 10.10.10.2:80>
      ServerAdmin webmaster@hp.com.csnet.uccs.edu
      DocumentRoot /var/www/html/hp.com.csnet.uccs.edu
      ServerName hp.com.csnet.uccs.edu
      ErrorLog logs/hp.com.csnet.uccs.edu-error_log
      CustomLog logs/hp.com.csnet.uccs.edu-access_log common
      </VirtualHost>
      
  • cp httpd.conf.new httpd.conf
• Create the document root directories and default web pages
  • Create ibm.com.csnet.uccs.edu, dell.com.csnet.uccs.edu, and hp.com.csnet.uccs.edu document root directories in /var/www/html
  • Create index.html file in those directories with the following content to identfy the web site.
    <h1>This is YYY.com.csnet.uccs.edu for cs526 ZZZ-based virtual hosting by <your name></h1>
  • To speed thing up, I have created three document directories in /media/floppy/ you can copy them to /var/www/html
  • But make sure you change the webmaster name in index.html to your name.
• Setup IP-based Web Hosting
  • ifconfig eth1:0 10.10.10.2
    #create ethernet alias for hp.com.csnet.uccs.edu web site.
  • Note that in previous step, we have included the related Apache directives in httpd.conf file.
• Restart apache with "apachectl restart"
• Access the default web pages of all three web sites from the web browsers.
  • Click the browser icon right by the Action menu. Start three firefox browsers.
  • Enter http://ibm.com.csnet.uccs.edu/, http://dell.com.csnet.uccs.edu/ and http://hp.com.csnet.uccs.edu/ and verify if the web pages are correctly delivered.
  • Hit Right-Alt key to return cursor control back to the host XP machine. Take the snapshots of the VPC image with the three web sites by hitting alt-Print Screen or simply Print-Screen, then cut and paste to your hw2 document.
  • Here is an example of snapshot image:
    
    

• In this exercise, we will configure a user model linxu virutal machine with host name sis-orig to host a site and give the user total control of the machine. This machine will use 10.10.10.13 as IP address. You are to configure the apache1.3.28 server on this UML virtual machine to serve the default web page of sis-orig.csnet.uccs.edu.
• In a terminal window of fc3c virtual machine, "cd ~/sis"
• In sis directory, we have the following files:
  • linux: a copy of User Model Linux generated with Linux 2.6.8 kernel.
  • root_fsSW9_sisbak is the file containing the root file system of a Slackware Linux distribution.
  • setupSNAT.sh: a shell script which setups ip_forwarding for fc3cUml to relay sis-orig to the Internet. sis-orig is setup with default gateway point to 10.10.10.1 (the IP address of eth1 on fc3c). All packets from sis-orig to Internet will be sent to 10.10.10.1 first. fc3c then copy it to its eth0 and sent it out. Note that for this homework we will contact Internet and therefore, we do not need to run this shell script. Here is the content of setupSNAT.sh:
    
    ifconfig eth1 10.10.10.1
    echo "1" > /proc/sys/net/ipv4/ip_forward
    iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
    
    
  • sis.sh the shell script that uses linux as command and specifies the root file system and network interface to be used by the User Model Linux virtual machine. Here is the content of sis.sh
    
    ./linux ubd0=root_fsSW9_sisbak umid=sis eth0=tuntap,,,10.10.10.12 mem=96M udb2=swap
    
    We configure this linux machine to use root_fsSW9_sisback as file system, use sis as umid, eth0 is configured to use tuntap emulator and associated with 10.10.10.12 IP address on the host side, and use 96MB of fc3c's main memory.
  • For more detail of the User Model Linux command see the related how-to manual.
    
    
• type "./sis.sh" to start sis-orig virtual machine.
• You should see the Slackware Linux machine boot squence. If the virtual machine was not shut down properly, the uml virtual machine will try to fix the file system and you see a percentage number of file system check progress, showing on the console. You may have to repeat the ./sis.sh command after the file system is fixed.
• At the end of the boot sequence, you will see an X window appear with sis-orig: prompt for login. The original terminal window will also show the same login prompt.
• Use root as login and enter related password (same as for all exercises).
• Type "ifconfig eth0 10.10.10.13" and "route add default gw 10.10.10.1".
• Type "ping 10.10.10.1" to confirm that there is a connection between sis-orig and fc3c.
• vi /etc/resolv.conf
• Add "nameserver 10.10.10.1" right after search command.
• Perform DNS query "nslookup sis-orig.csnet.uccs.edu".
• You will find the DNS server on 10.10.10.1 (fc3c) does not respond the query.
• It turns out that the default fc3c security setting is very tight and its firewall only allows packets with SSH (port 22) and WWW (port 80) to go through. We need to add DNS (port 53) to the list of ports that allows outside access.
• To do that, on fc3c virtual machine tool bar, select Application | system setting | security. This will bring up the applet for security level setting.
• Type "53:udp" to the textbox with the lablel "other ports (1024:tcp):". Click OK.
• Now go back to the console window of sis-orig and perform "nslookup sis-orig.csnet.uccs.edu". You should get response now.
• Edit /etc/apache/httpd.conf (Note that on slackware distribution, the configuration file location is different fron that of fc3).
• Search for ServerName directive and enter
  ServerName sis-orig.csnet.uccs.edu
• vi /etc/hosts
• Make sure it has the following correct entries (remove the old 127.0.0.1 entry that has affending syntax):
  127.0.0.1 localhost.localdomain.com localhost
  10.10.10.13 sis-orig.csnet.uccs.edu sis-orig
• Create the default web page for sis-orig.csnet.uccs.edu similar to those of Exercise 1. Note that on slackware, the default document root directory is located in /var/www/htdocs not /var/www/html
• Start web server with "apachectl start"
• From the web browser of fc3c, type "http://sis-orig.csnet.uccs.edu/" to verify the web page on sis-orig is up.
• Capture the snapshop of the browser with that default web page and reference it as url in your hw2. Note that here we are running a virtual machine inside another virtual machine. The performance will be slow.
  

• Q1. Discuss the pro and con of using 1) Name-based Virtual Hosting, 2) IP-based Virtual Hosting, and 3) virtual machine based Virtual Hosting. In terms of
  • resource utililzation,
  • setup overhead,
  • performance,
  • ease of use, and
  • user control
• Q2. The following are the performance of those web sites on S50.csnet machine using httperf. Discuss what these data tell us. The numbers are in unit of requests/second. Note that here UML virtual machines are running on a Fedora Core 3 real host machine. The performance of the UML virtual machine will be much better than that runs on VPC in EAS 138.