Transcript ITI-520: Web Technology Web Server Setup

ITI-520: Web Technology
Web Server Setup
Meeting 1: Introduction to the Internet,
World Wide Web and Web Servers
Rutgers University Internet Institute
Instructor: Chris Uriarte
Web Technology – Web Server Setup : Chris Uriarte
Course Overview and Goals
• This course will teach you how to install,
configure, and administer a Web server that
runs on a Unix system and can be used to
deliver dynamic content.
• The course objectives will be achieved
through a combination of lectures,
demonstrations, and hands-on exercises.
Web Technology – Web Server Setup : Chris Uriarte
About Your Instructor…
• Chris Uriarte – [email protected]
• Contact me anytime via email or telephone:
(732) 888-0088 x47.
Web Technology – Web Server Setup : Chris Uriarte
About Your Classmates…
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Introductions
What do you do?
What do you do with computers?
Why are you taking this class?
Web Technology – Web Server Setup : Chris Uriarte
What This Course Is and Is Not
• The purpose of the course is to teach you how to
setup a Web server. This means you will be
learning how to use tools to deliver content for the
World Wide Web, not to create content.
• The Rutgers Internet Institute offers many other
courses designed to teach you how to create
content for the World Wide Web: World Wide Web
Publisher (I & II) Certificates and World Wide
Web Developer Certificate.
Web Technology – Web Server Setup : Chris Uriarte
World Wide Web Unix
Administrator Certificate
• This course is one of four required to
receive the World Wide Web Unix
Administrator Certificate.
• Other courses: ITI-480 Unix Fundamentals,
ITI-481 Unix Administration & ITI-510
Computer Networks
Web Technology – Web Server Setup : Chris Uriarte
Prerequisites
• Familiarity with a Web browser such as
Netscape or Internet Explorer.
• You should have user-level experience with
UNIX and must be familiar with the use of
a UNIX text editor like vi, emacs and pico.
• Some level of experience with creating
HTML documents may be helpful.
Web Technology – Web Server Setup : Chris Uriarte
Class Schedule
• Week 1: Introduction to the Internet, the
World Wide Web, and Web Servers
• Week 2: Installing and Configuring the
Apache Web Server
• Week 3:Extending Apache: Advanced
Topics
• Week 4: Web Security: Secure Servers and
Securing Your Server
Web Technology – Web Server Setup : Chris Uriarte
Course Resources
• Textbook: Professional Apache by Peter
Wainwright (Wrox Press, 1999).
• User account on Linux server
iti.rutgers.edu.
Web Technology – Web Server Setup : Chris Uriarte
How does the World Wide Web
Work?
• Works on a client/server model. The Web
server is the server component. The Web
browser is the client component. Purpose of the
Web server is to provide documents to clients.
• Web servers, Web browsers, and the
information that is shared between them
through the Hypertext Transfer Protocol
(HTTP) protocol make up the World Wide
Web.
Web Technology – Web Server Setup : Chris Uriarte
History of the World Wide Web
• Grew out of the Internet, a network of networks
designed that began in the early 1970’s and was
used to support a variety of services (including
telnet, ftp, Usenet, email, and gopher) that
communicated via TCP/IP (Transmission Control
Protocol/Internet Protocol).
• In 1989, Tim Berners-Lee at CERN developed a
new system to simplify document distribution and
to allow documents to be linked together. Called
the “WorldWideWeb.”
Web Technology – Web Server Setup : Chris Uriarte
Web History, con’t.
• In 1993, the National Center for
Supercomputing Applications (NSCA)
released to the public a NCSA server
software and a GUI Web browser called
Mosaic. Quickly became popular.
• Mosaic became Netscape
Web Technology – Web Server Setup : Chris Uriarte
Who is a Webmaster?
• A Webmaster is someone responsible for the
content and/or management of a Web site
and/or a Web server.
Web Technology – Web Server Setup : Chris Uriarte
What Roles Do Webmasters
Play?
• Web Designers – Create graphical elements and
determine layout of Website.
• Content Providers- Create and edit HTML
documents.
• Web Developers – Write CGI, Java, JavaScript,
ASP, PHP, and other scripts or programs that
are used to deliver dynamic content.
Web Technology – Web Server Setup : Chris Uriarte
Webmaster Roles, con’t.
• Administrators – Responsible for
maintaining the Web server software and
often the operating system and hardware
where the Web server is installed.
• For most organizations, these
responsibilities tend to be split over
multiple job positions except for very
small and simple Web sites.
Web Technology – Web Server Setup : Chris Uriarte
Planning Your Server
• How and where will you host it?
• What kind of hardware will you use?
• What kind of Operating System will the hardware
run?
• What Web server software will you use?
• What domain name will your site use?
• Answers to above questions usually determined by
budget, staffing, and existing infrastructure of
your organization.
Web Technology – Web Server Setup : Chris Uriarte
Hosting Your Server: Use an
ISP (Internet Service Provider)
• Free Page Site – For personal use, limited space
and tools, adds advertisements. (examples: Yahoo,
Tripod, Xoom, etc.)
• Personal Page Site – For personal use, usually
included with dialup account (about $20 per
month), 2-20 MB disk space, none or limited
access to server-based technologies for delivering
dynamic content, generally under your ISP’s
domain. (Website URL usually looks something
like: http://www.yourisp.com/~yourusername)
Web Technology – Web Server Setup : Chris Uriarte
Hosting Your Server, con’t.
• Virtual Host – For business or personal use, share
a machine with other domains, can use your own
domain (http://www.yourdomain.com), should
provide a fairly wide range of tools for building
more complex Websites, costs based on disk usage
and traffic, ranges from $10 to several hundreds of
dollars a month. Generally available through all
ISPs and Hosting-only providors such as Highway
Technologies (http://www.hway.net) and
YourDomainHost
(http://www.yourdomainhost.com)
Web Technology – Web Server Setup : Chris Uriarte
Hosting Your Server, con’t.
• Dedicated Server – For business use, ISP owns
and runs the machine, your organization dictates
the configuration and has exclusive access to the
system, expensive.
• Co-Located Server – For business use, your
organization owns the hardware and software and
is responsible for maintaining it, ISP houses the
system and provides a network connection, pricing
determined by bandwidth requirements.
Web Technology – Web Server Setup : Chris Uriarte
Hosting Your Server: Do It
Yourself: Networking Options
• For an Intranet Server– Need a LAN (local area
network).
• For an Internet Server – Need a dedicated Internet
connection. Internet Connectivity Options:
– POTS (up to 56Kbps) – not practical for business use
– ISDN (128Kbps) – only a good choice if cable or DSL
is not available
– Cable (512Kbps – 10Mbps)
– DSL (128kps – 1.54 Mbps+)
– T-1 (up to 1.54Mbps) – full, fractional, or burstable
– T-3 (up to 45 Mbps)
Web Technology – Web Server Setup : Chris Uriarte
Finding an ISP
• Setting up a Internet Web site will require
you to purchase some level of services from
an ISP.
• The List – http://thelist.com
Web Technology – Web Server Setup : Chris Uriarte
Hosting Your Server:
Hardware Options
• Need to select a machine architecture (i.e
Intel Compatible PC, Sun, Macintosh G4).
• Processor speed and number of processors.
• RAM and Disk Space.
• NIC card.
• Price can range from several hundred
dollars to thousands of dollars.
Web Technology – Web Server Setup : Chris Uriarte
Hosting Your Server:
Operating System Options
• Commercial Versions of Unix (i.e. Solaris, Irix,
HP-UX, AIX, MacOS X).
• Free Versions of Unix (i.e. Linux, FreeBSD).
• Microsoft Windows (9x, NT, Windows 2000).
• Novell NetWare
• Windows vs. Unix – raises issues of easy of use,
stability, scalability, open source, and pricing.
Web Technology – Web Server Setup : Chris Uriarte
Hosting Your Server: Web
Server Software Options
• According to the Netcraft Web Server
Survey (http://www.netcraft.com), as of
January 2000, three Web server software
distributions support over 90% of all Web
servers on the Internet:
– Apache 61.66%
– Microsoft Internet Information Server 19.63%
– Netscape Enterprise 7.22%
Web Technology – Web Server Setup : Chris Uriarte
Web Server Software Options:
Apache
• “The standard” for UNIX web servers.
• Originally based on NCSA httpd code.
• Can be installed under most Unix variants
and Windows. Binary versions available for
many operating systems.
• Uses file-based configuration, although GUI
tools are also available.
Web Technology – Web Server Setup : Chris Uriarte
Introduction to Apache, con’t.
• Unix versions very stable. Windows version less
mature (beta-level code).
• Very Fast and uses resources efficiently.
• Freely distributed source code. Can be modified
for commercial or non-commercial use.
• Price: Free
• See http://www.apache.org for more information.
Web Technology – Web Server Setup : Chris Uriarte
Web Server Software Options:
Netscape Server
• Sometimes referred to as the iPlanet server
• Distributed through Sun-Netscape Alliance called
iPlanet.
• Server packages: iPlanet/Netscape Enterprise
Server, Netscape Fast-Track Server.
• Runs under Windows NT, Solaris, Irix, HP-UX,
Digital Unix, AIX, Linux (coming soon).
Web Technology – Web Server Setup : Chris Uriarte
Netscape iPlanet Server, con’t.
• Uses Web-based administration.
• Can be resource intensive.
• Price: $1495 per processor for Enterprise
Server
• See
http://www.iplanet.com/products/infrastruct
ure/web_servers for more information.
Web Technology – Web Server Setup : Chris Uriarte
Web Server Software Options:
Microsoft Internet Information
Server
• Most popular for NT-based web servers.
• Runs only under Windows NT Server. IIS
v4 is the most popular release. IIS v5 was
released with Windows 2000 Server.
• GUI-based administration. Web-based
administration available as well.
• May not scale well.
Web Technology – Web Server Setup : Chris Uriarte
Microsoft IIS, con’t.
• Source code not available. Extendable
through Microsoft’s Internet Server API
(ISAPI).
• Price: Free with NT Server 4.0
• See
http://www.microsoft.com/ntserver/web/d
efault.asp for more information.
Web Technology – Web Server Setup : Chris Uriarte
Important Notes about Web
Server Hardware
• Web Servers need fast disk access and a lot
of RAM to handle high-volumes of traffic.
– Not unusual to see web servers with 1GB of
RAM and 10,000RPM hard drives.
• Processor speed and performance becomes
very important when delivering dynamic
content via CGI scripts, Server Side
Includes or other web applications.
Web Technology – Web Server Setup : Chris Uriarte
How the Internet Works:
Networking Basics
• For a Web server to be useful it will need to
be attached to a network.
• Minimum requirements for a computer
network – at least two computers that have
a media and a method of communicating.
• All Internet applications use TCP/IP
(Transmission Control Protocol/Internet
Protocol) for low-level communications.
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: TCP/IP
• TCP/IP is actually a combination of 2
protocols:
• A transport layer protocol called the
Transmission Control Protocol (TCP)
• A network protocol called the Internet
Protocol (IP)
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: IP Addresses
• TCP/IP uses IP address to identify different
devices. Every computer on the Internet must
have a least one unique IP address.
• IPv4: IP address are four 8-bit numbers
separated by dots: 165.230.30.68
– Usually divided in three parts:
– 165.230 is one of Rutgers’ networks – e.g. no one else
has addresses starting with 165.230
– 30 is the subnet portion of the address
– 68 is the particular node, or host portion of the address
• Division not necessarily on octet boundary.
Web Technology – Web Server Setup : Chris Uriarte
TCP/IP: Two Friends, Working
Together
• IP - An IP address represents a machine’s identity
on the internet and tells other machines how to get
to it – similar to your street address (e.g. 123 Main
Street, Anytown, USA).
• TCP is a mechanism used to ensure that anything
sent to a specific IP address makes it there in one
piece. – similar to the Post Office.
• Together, TCP/IP assures that anything sent to a
server on the Internet is delivered to the right
place in one complete piece.
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: IP
Addresses
• IP addresses no longer being distributed by
classes – blocks are distributed to ISPs on an
as-needed basis and must be justified.
• IP addresses are hard to come by. How do you
get them?
– Your ISP received an “address space” from the ARIN
(http://www.arin.org)
– You receive IP addresses from your ISP.
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: Tools
• Network interfaces need to be assigned IP
addresses.
• Interfaces can be configured using ifconfig
command on UNIX machines.
• Type ifconfig –a to view current configuration
settings.
• Additional tools for network monitoring: ping,
traceroute, tcpdump, netstat, arp, snoop.
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: DNS
• IP addresses are usually paired with more
human-friendly names: Domain Name
System (DNS).
internet.rutgers.edu
Hostname
Organization Top-level domain
• Other top-level domains include .com, .gov,
.org, etc. There are also country-specific
domains like .uk, .ca, .jp, etc.
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: DNS, con’t.
• Domain name information is maintained through a
distributed database of host name/ IP address
pairing.
• The Network Information Center (NIC) manages
the top-level domains, delegates authority for
second-level domains, and maintains a database of
registered name servers for all second-level
domains.
• Host name assignments maintained through zone
files on primary DNS server. Secondary DNS
server gets zone file from primary server.
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: DNS, con’t.
• Network Solutions (previously the InterNic)
registers domain names – See
http://www.networksolutions.com. Other
registrars include Register.com
• Costs range from $20 to $50 per year.
• ISP’s beginning to offer domain name
registration as part of other packages.
• Need to register a primary and secondary
domain name servers for your domain and
arrange to have zone files created on DNS
servers.
Web Technology – Web Server Setup : Chris Uriarte
DNS Overview: If DNS Servers Could Talk…
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: DNS Tools
• There are several tools for for monitoring DNS
information:
– whois – tells you the owner and primary DNS servers
associated with a domain (e.g. whois yahoo.com). Also
available via web browser at
www.networksolutions.com.
– nslookup and host – tell you IP address information for
a particular hostname on the internet (e.g. nslookup
www.yahoo.com or host www.rutgers.edu)
Web Technology – Web Server Setup : Chris Uriarte
DNS Exercise
• What are IP addresses of the DNS servers
that contain information about rutgers.edu?
• What are the IP address of:
– www.retaildecisions.com
– abusaday.admin.cju.com
– www.linux.org
Web Technology – Web Server Setup : Chris Uriarte
Networking Basics: Ports
• Servers tend to run a number of services. A single
NIC can be used to provide multiple services
through ports.
• Servers with Internet-related services listen on
specific ports. Clients contact server by specifying
an IP address and a connection port.
• Common services and port numbers:
– smtp 25, ftp 21, telnet 23, http/web 80, https/ssl 443
– A list of services and ports is contained in the
/etc/services file
• Ports below 1024 are reserved for system services
and can only be used by programs started by root.
Web Technology – Web Server Setup : Chris Uriarte
Web Servers and UNIX Systems
• Most web servers run on port 80 – the standard
web port
• Web server software usually runs on UNIX system
as some user other than root. It’s considered a
security risk to run the web server software as
root.
• The web server software binary is httpd. Web
server software is often refered to as “the httpd”
Web Technology – Web Server Setup : Chris Uriarte
Uniform Resource Locator
(URL)
• URL: a fancy way of saying “web site
address”
• Anatomy of a URL:
http://internet.rutgers.edu:80/ITI520/index.html
Protocol
Hostname
Port Number
Path To File
Web Technology – Web Server Setup : Chris Uriarte
HTTP – An Introduction
• HTTP – The Hypertext Transfer Protocol
– The protocol used between web clients
(browsers) and web servers.
– Web browsers “ask” for a specific web page
from the server, who returns the content
Web Technology – Web Server Setup : Chris Uriarte
HTTP: Example and Exercise
• You can emulate the HTTP conversation
between a browser and a server:
– telnet to the internet.rutgers.edu machine, port
80, e.g. telnet internet.rutgers.edu 80 from the
UNIX command line.
– Type: “GET HTTP/1.0 /” Press Enter twice.
– The server returns the HTML (web page code),
which is usually interpreted and displayed by
your web browser.
Web Technology – Web Server Setup : Chris Uriarte
Unix Tools and Commands
• File Editors: vi, emacs, pico
• File system navigation: cd
• File management: mv, rm, mkdir,rmdir, ls,
chmod, ln
• Archiving and compression: tar, gzip
• ***Process management: ps, kill
• Man pages available for all these
commands, e.g “man rmdir”
Web Technology – Web Server Setup : Chris Uriarte
UNIX Process Management
• UNIX Processes are managed using the ps
and kill commands
– ps is used to list processes running on the
system
– kill is used to kill and restart processes running
on the system
• Every time you start a new program (pico,
vi, bash, etc.) a process is created and you
are the owner of that process.
Web Technology – Web Server Setup : Chris Uriarte
Process Management Exercises
• You can type ps –aux to see all the
processes running on a system. This will
list the process owner, process ID (PID) and
the command being run.
• You can kill any PID, as long as you are the
owner of the process.
• ps –u shows all the processes your are
currently running
Web Technology – Web Server Setup : Chris Uriarte
Process Management Exercises,
con’t.
• Open up a new terminal window and type vi
foo.txt. This will create a new process on the
system that you own.
• Switch back to your original terminal
window. Locate the process ID for your vi
session and kill it.
Web Technology – Web Server Setup : Chris Uriarte
Reading for Next Week…
• Read Chapters 1-5 in Professional Apache.
Web Technology – Web Server Setup : Chris Uriarte