Transcript here in MS PowerPoint format - cju.com

WMB-520: Web Technology
Web Server Setup
Meeting 2: Apache Installation and Initial
Configuration
Rutgers University Center for Applied Computing Technology
Instructor: Chris Uriarte
Web Technology – Web Server Setup : Chris Uriarte
Apache
• The world’s leading web server software
(powers 65% of all web sites in the world)
• Runs on UNIX and Windows platforms.
UNIX version is the most stable and most
widely used.
• Configuration is the same on all UNIX
platforms, varies slightly on Windows
systems.
Web Technology – Web Server Setup : Chris Uriarte
How Do I Get Apache?
• There are currently two supported releases of Apache: v1.3 and v2.0.
Version 1.3 is the most widely used (95% of all Apache installation),
but version 2.0 will become more popular over the next 12-18 months.
– There are many subversions released throughout the lifetime of a major
version (i.e. 1.3.10)
• You can download it from the Apache Website:
http://www.apache.org/dist/
– Binary Versions – software that is ready-to-use for your specific operating
system platform
– Source Code – the computer code used to build Apache. You must use a
compiler to build the code.
• You can buy a Unix distribution that comes bundled with Apache prebuilt (most Linux distributions include Apache by default).
Web Technology – Web Server Setup : Chris Uriarte
Installing Apache from Source
• Allows you to build the Apache binaries from
scratch.
• Optimizes Apache for the platform on which it
will run.
• Allows you to specify special server features at
build-time.
• You need a C compiler (i.e. gcc) installed on your
system to compile source code, which is included
in most UNIX distributions.
Web Technology – Web Server Setup : Chris Uriarte
Apache Modules
• Apache has a modular structure. Only a core set
of features exists within the main Apache
executable.
• Apache Modules provide additional functionalityto
Apache.
• Example Module: mod_speling: The Speling
module attempts to correct misspellings of URLs
that users might have entered, namely by checking
capitalization or by allowing up to one misspelling
(character insertion, omission, transposition, typo).
Web Technology – Web Server Setup : Chris Uriarte
Apache: Static vs. Dynamic
Servers
• Static Servers
– Must decide at build time what modules to
include. Recompiling will be necessary to add
modules later.
• Dynamic Servers
– Allows you to utilize new modules without recompiling apache.
Web Technology – Web Server Setup : Chris Uriarte
Static vs. Dynamic Apache
• Building a static (standard) Apache distribution
limits you to the modules you choose when you
compile the server.
• However, using Apache with dynamic modules
makes apache more difficult to administer,
perform slower and increases its memory
requirements.
• Consider building a static server, as the need to
add new modules is not very common and recompiling Apache is simple.
Web Technology – Web Server Setup : Chris Uriarte
Installing Apache Source
• Create a directory under your blender.rutgers.edu
home directory called “apache”
– mkdir apache
• You now need to obtain the Apache source file
(which you’d usually do from
http://www.apache.org/dist). You can copy the
source that is contained locally on the
blender.rutgers.edu server:
– cd apache
– cp ~chrisjur/apache_1.3.27.tar.gz .
• You should now have the Apache source file under
your home directory in
/home/<username>/apache.
Web Technology – Web Server Setup : Chris Uriarte
Unzipping and Untar’ing the
Source File
• You now have the Apache source distribution
under your home directory in
/home/<username>/apache.
• The source file is actually a group of tar’ed files
and directories, which is then zipped using the
gzip utility.
• You can untar and unzip the source distribution by
issuing:
– tar –xvzf apache_1.3.27.tar.gz
Web Technology – Web Server Setup : Chris Uriarte
Unzipping and Untar’ing the
Source File – con’t.
• Unpacking the distribution file will create
another directory under
/home/<username>/apache called
“apache_1.3.27”
(/home/<username>/apache/apache_1.3.27).
• “cd” to the apache_1.3.27 to view the files
and directories that are included in the
distribution.
Web Technology – Web Server Setup : Chris Uriarte
Sample Directory Listing from
Source Distribution
iti% cd apache_1.3.27
iti% ls
ABOUT_APACHE LICENSE
README.NT
Announcement Makefile
README.configure
INSTALL
Makefile.tmpl WARNING-NT.TXT
KEYS
README
cgi-bin
iti% ls -al
total 272
drwx-----8 chrisjur users
4096 Oct
drwx-----13 chrisjur users
4096 Oct
-rw------1 chrisjur users
12957 Mar
-rw------1 chrisjur users
2922 Feb
-rw------1 chrisjur users
27964 Dec
-rw------1 chrisjur users
35773 Aug
-rw------1 chrisjur users
2848 Jan
-rw------1 chrisjur users
26929 Oct
-rw------1 chrisjur users
26758 Jan
-rw------1 chrisjur users
2046 Apr
-rw------1 chrisjur users
3132 Mar
-rw------1 chrisjur users
11176 Dec
-rw------1 chrisjur users
331 Sep
drwx-----2 chrisjur users
4096 Feb
drwx-----2 chrisjur users
4096 Feb
-rw------1 chrisjur users
5909 Dec
-rwx--x--x
1 chrisjur users
312 Oct
-rwx-----1 chrisjur users
56062 Feb
drwx-----3 chrisjur users
4096 Feb
drwx-----3 chrisjur users
4096 Feb
drwx-----2 chrisjur users
4096 Feb
drwx-----11 chrisjur users
4096 Oct
conf
config.layout
config.status
configure
15
15
31
23
21
20
1
15
11
1
19
20
21
23
23
28
15
5
23
23
23
15
20:21
21:10
1999
2000
1999
1999
1999
20:20
2000
1998
1999
1999
1998
2000
2000
1999
20:20
2000
2000
2000
2000
20:21
htdocs
icons
logs
src
.
..
ABOUT_APACHE
Announcement
INSTALL
KEYS
LICENSE
Makefile
Makefile.tmpl
README
README.NT
README.configure
WARNING-NT.TXT
cgi-bin
conf
config.layout
config.status
configure
htdocs
icons
logs
src
Web Technology – Web Server Setup : Chris Uriarte
Apache Installation: Step 1
• Before actually building the Apache binaries, you
must run a configure utility, which inspects your
system and prepares the distribution for
compiling.
• The configure script is located in the directory that
was created when you unpacked the Apache
source distribution (i.e.
/home/itiXXX/apache/apache_1.3.27)
• The included INSTALL file has instructions on
how to configure and compile Apache.
Web Technology – Web Server Setup : Chris Uriarte
Apache Installation: Step 1
con’t.
• Run the configure script like this:
./configure --prefix=/home/itiXXX/apache
• The “prefix” flag tells Apache where you
actually want to install the software and
configuration files.
• It also builds the Apache software so it
knows where to look for configuration files
Web Technology – Web Server Setup : Chris Uriarte
Apache Installation: Step 2
• After the configure script runs successfully, you
now need to compile the software code into the
actual binaries.
• You can start the compile by issuing the make
command in the Apache distribution directory, i.e:
– cd /home/itiXXX/apache/apache_1.3.27
– make
• The compile process will take 2-10 minutes,
depending on the speed of your system.
Web Technology – Web Server Setup : Chris Uriarte
Apache Installation: Step 3
• When the compile is complete, you can install the
software and configuration files by issuing the
make install command.
• This will copy the built binaries and configuration
files into the /home/<username>/apache directory
you specified when you ran the configuration
script. We will now refer to this directory as the
Server Root directory.
Web Technology – Web Server Setup : Chris Uriarte
The Server Root Directory
• Examine the contents of the Server Root directory.
You now have a group of directories Apache uses:
– bin: the location of the actual apache program and
other utilities
– conf: location of the configuration files
– htdocs: the directory where web pages and and
associated files are kept
– logs: where apache keeps log files
– man: UNIX man pages for apache
– cgi-bin: the directory where CGI scripts are kept
Web Technology – Web Server Setup : Chris Uriarte
Apache and Privileged Ports
• Any TCP/IP port <1024 is considered a
privileged port.
• Privileged Ports can only be accessed by
applications started by the root (system
admin) user.
• Therefore, since you are not the root user on
this system, you must configure Apache to
use a port >1024.
Web Technology – Web Server Setup : Chris Uriarte
Quickstart: Change the Port
Number your Apache Server
Uses
• “cd” to the Apache conf directory
(/home/itiXXX/apache/conf)
• Use a text editor to open the httpd.conf file,
which is the main Apache configuration file.
• Find the line that says “Port XX”. Your file
may say “Port 8080” or some other number.
Web Technology – Web Server Setup : Chris Uriarte
Change your Apache Port, con’t.
• Replace the number next to the “Port”
directive to a number that corresponds to
you.
• Use the numeric portion of your
blender.rutgers.edu username. For example,
if your username is iti2345, use port 2345 as
your port number.
• Exit your editor and save the file.
Web Technology – Web Server Setup : Chris Uriarte
Getting Ready to Run Apache for
the First Time…
• Apache is configured to look for web documents
in the htdocs directory under the server root
(/home/itiXXX/apache/htdocs).
– This directory is known as the “Document Root”
• Be default, a page called “index.html” is the first
page of a the website returned to clients.
• Create an index.html file in your htdocs directory
that contains the text “Hello World. My name is
<Your Name>”
Web Technology – Web Server Setup : Chris Uriarte
Starting Apache: The “Hard”
Way
• The actual Apache binary is called httpd and
it resides in the Apache /bin directory.
• You can start Apache by simply executing
the httpd command
– cd apache/bin
– ./httpd
• Apache is now started!
Web Technology – Web Server Setup : Chris Uriarte
Verify that Your Instance of
Apache is Working
• Point a web browser to
http://blender.rutgers.edu:<PORT>
(recall, you configured the port number in the
httpd.conf file to be the numeric portion of your
iti username)
• You should see your default web page
appear (the contents of the
htdocs/index.html document we created at
earlier)
Web Technology – Web Server Setup : Chris Uriarte
Stopping Apache: The “Hard”
Way
• Remember, every time you execute a program on
a UNIX operating system, a process is created
• Apache creates a file called httpd.pid in its logs
directory. This file contains the parent process ID
of the Apache process.
• You can kill the process by using the kill
command
• You can kill Apache by issuing the following
commend:
– kill –TERM `cat
/home/<username>/apache/logs/httpd.pid`
Web Technology – Web Server Setup : Chris Uriarte
Starting and Stopping Apache:
The “Easy” Way with apachectl
• A script called apachectl is included in the
apache/bin directory.
• You can use apachectl to start, stop and
restart the Apache server – very simple to
use:
– cd /home/<username>/apache/bin/
– ./apachectl {start|stop|restart}
Web Technology – Web Server Setup : Chris Uriarte
Apache Configuration Files
• Configuration files are placed in the conf/
directory and include:
– httpd.conf – master configuration file
– access.conf and srm.conf – no longer used
• Since version 1.3.4, all you configuration is done
in the httpd.conf file – the srm.conf and
access.conf files are no longer needed.
• Apache needs to know location of httpd.conf file
to start. If httpd.conf needs to move after initial
install need to specify location with –f option
when starting server.
– httpd –f /path/to/httpd/.conf
Web Technology – Web Server Setup : Chris Uriarte
httpd.conf: IP address and Port
• The BindAddress and Port directives
in the httpd.conf tell Apache which IP
addresses and ports to listen on. Usage:
Tells Apache to use the default IP address for this system:
BindAddress *
Tells Apache to “listen” for web requests on Port 80:
Port 80
Web Technology – Web Server Setup : Chris Uriarte
Tell Apache to Listen To
Additional Ports and IP addresses
• The Listen directive in the httpd.conf tells Apache
to listen to additional Ports and/or Port/IP address
combinations.
• Usage:
Listen <Port Number> or
Listen <IP>:<Port Number>
• These IP/Ports are used in addition to the IP and
Port specified in the BindAddress and Port
directive described earlier.
Web Technology – Web Server Setup : Chris Uriarte
httpd.conf: Basic
Configuration Directives
• ServerName blender.rutgers.edu –
The name of this server we use to respond
to web clients with. If the server does not
have a real internet name, use the IP address
instead.
• ServerType standalone - We always set
this to standalone.
Web Technology – Web Server Setup : Chris Uriarte
httpd.conf: Basic Configuration
Directives
• User nobody, Group nobody - For
security reasons, we usually run Apache assumes
the identity of a non-root user and group on the
system. A lot of times we run Apache as the
nobody user/group.
• ServerAdmin
[email protected] - A contact
address to report problems – returned to the web
client when an error occurs.
Web Technology – Web Server Setup : Chris Uriarte
httpd.conf: Basic Configuration
• ServerRoot /home/<username>/apache -
Where Apache keeps all its essential files.
• DocumentRoot /usr/local/apache/htdocs -
Where the actual Web pages reside.
• ErrorLog
/home/<username>/apache/logs/error_log –
The location of the Apache error log
• PidFile
/home/<username>/apache/logs/httpd.pid -
Process id for the Apache parent process. Used
with the kill command to stop Apache.
Web Technology – Web Server Setup : Chris Uriarte
httpd.conf: Virtual Directories
• Sometime you want to create a Virtual
Directory, where a document directory may
not exist under your htdocs directory, but
you want web clients to have access to it.
• This is configured using the Alias directive
in the httpd.conf, usage:
Alias <virtualdirectory> <real directory>
Web Technology – Web Server Setup : Chris Uriarte
Virtual Directories, con’t.
• For example, if your Document Root is the default
htdocs directory and you want web client to access
a directory that contains Icons
(/home/<username>/apache/icons), you can create
a Virtual Virtual Directory called myicons like
this:
Alias /myicons
/home/<username>/apache/icons
• Now web clients can access this virtual directory
by going to
http://blender.rutgers.edu:XXXX/myicons
to view
Web Technology – Web Server Setup : Chris Uriarte
httpd.conf: Redirects
• The Redirect directive allows web clients to access
a URL on your system and be re-directed to a
remote URL somewhere else.
• Usage:
Redirect /localpath http://remote-url
• Example:
Redirect /photos
http://members.yahoo.com/user/photos
Redirects all request to http://yoursite.com/photos to
http://members.yahoo.com/user/photos
• Useful when you move portions of a webpage
Web Technology – Web Server Setup : Chris Uriarte
Giving Web Access to Users on
the System
• Individual users on your system may wan the
ability to post web content.
• The UserDir Apache directive, allows each user on
the system to create an special directory used to
contain web content.
• Usage: UserDir public_html
• Now system users can place all of their web
documents in a directory called public_html under
their home directory. These documents can be
accessed via the URL
http://systemname/~username.
Web Technology – Web Server Setup : Chris Uriarte
Access Control Files
• Per directory configuration files can be used to
supplement or override settings set on the server
level. Most commonly used to password-protect a
directory.
• Allows for “on-the-fly” changes. No need to
restart the server.
• Generally referred to as .htaccess files even
though the actual name of the file can be set in
httpd.conf: AccessFileName .htaccess
Web Technology – Web Server Setup : Chris Uriarte
Access Control Files, con’t.
• Level of overrides allowed should also be
set in httpd.conf:
• AllowOverride None|All|Options|Indexes|
FileInfo|AuthConfig|Limit
• Default is “All”.
• Access control file is placed in root of
directory for which configuration is being
modified.
Web Technology – Web Server Setup : Chris Uriarte
Access Restrictions by Location
• Access to directory contents can be granted or
denied by IP address, network, hostname or name.
<Directory /home/apache/apache/htdocs/restricted>
order deny,allow
deny from all
allow from 165.230.30.68 .rutgers.edu internet.rutgers.edu
</Directory>
• Best to control access by IP address rather than
hostname to avoid require DNS lookups for every
attempted connection.
• You can place these blocks access control blocks
in the httpd.conf file or in an .htaccess file.
Web Technology – Web Server Setup : Chris Uriarte
The Index File
• When a web browser points to a directory, rather
than a particular file (e.g.
http://www.internet.rutgers.edu/II/ITI520 vs.
http://www.internet.rutgers.edu/II/ITI520/index.html), Apache
looks for an index file, which is the default web
page for a particular directory.
• You can specify the name of acceptable index files
by using the DirectoryIndex directive in the
httpd.conf file.
• Usage: DirectoryIndex filename filename…
• Apache will look for the index file names
specified when a request is made to a directory.
Web Technology – Web Server Setup : Chris Uriarte
Indexing
• What happens if you type a URL into a browser
that points to a directory rather than a specific
file?
– Will load the index file if directory includes any of the
files specified with DirectoryIndex in httpd.conf:
DirectoryIndex index.html index.htm
• If no index file exists and indexing has been
enabled, will get a directory listing.
• If no index file exists and indexing has been
disabled, will get an error message.
• Advisable to leave indexing disabled for security
reasons unless there is a specific need for it.
Web Technology – Web Server Setup : Chris Uriarte
Indexing, con’t.
• To enable indexing in httpd.conf:
Options Indexes
• Fancy indexing generates listing that
includes representative icon, name, last
modified, size, and description:
IndexOptions FancyIndexing
• Indexing requires module mod_autoindex,
which is installed by default.
Web Technology – Web Server Setup : Chris Uriarte