setting up a web server

Institute for Visualization and Perception ResearchI VP R 1

© Copyright 1998 Haim Levkowitz

Setting up a Web server

• Setting up basic services ...

• Web server maintenance ...

• More features ...

Institute for Visualization and Perception ResearchI VP R 2

© Copyright 1998 Haim Levkowitz

Setting up basic services ...• Pre-compiled server

• Source + compilation

• Site-specific configuration

• Installing the server

• Starting the server

• Mapping URLs to documents ...

• Testing the server

• Setting up home pages ...

• Public access conventions ...

• Announcing server ...

Institute for Visualization and Perception ResearchI VP R 3

© Copyright 1998 Haim Levkowitz

httpd (NCSA) subdirectories ...

• cgi-bin

• conf

• icons

• logs

• support

Institute for Visualization and Perception ResearchI VP R 4

© Copyright 1998 Haim Levkowitz

Mapping URLs to documents ...

• Minimal URL to reach server: http://server-name ...

• Different port: http://server-name:port_number ...

• URL --> real dir translation ...

Institute for Visualization and Perception ResearchI VP R 5

© Copyright 1998 Haim Levkowitz

Minimal URL to reach server: http://server-name ...• No directory path / filename ==>server

returns

• index.html in ServerRoot directory or (if no file)

• directory index (like ls -1)

Institute for Visualization and Perception ResearchI VP R 6

© Copyright 1998 Haim Levkowitz

Different port: http://server-name:port_number ...• Append virtual name of document

(except root-dir index)

• Path to doc (not absolute)

Institute for Visualization and Perception ResearchI VP R 7

© Copyright 1998 Haim Levkowitz

URL --> real dir translation ...• Virtual dir in beg. URL path? (def'd in Alias /

ScriptAlias in srm.conf)• Yes: replace vir. dir. w/real dir.

• Prefix of /~user-name?• Yes: ~user-name/public_html/<file>

• Doesn't exist ==> error• Else DocumentRoot at beg. Path• Alias, ScriptAlias, UserDir directives in srm.conf ....

Institute for Visualization and Perception ResearchI VP R 8

© Copyright 1998 Haim Levkowitz

Alias, ScriptAlias, UserDir directives in srm.conf ....

• Virtual directory• E.g.,

• Alias /icons /usr/local/etc/httpd/icons/• http://server-name/icons/mybitmap.xbm

==>• /usr/local/etc/httpd/icons/

mybitmap.xbm

Institute for Visualization and Perception ResearchI VP R 9

© Copyright 1998 Haim Levkowitz

Setting up home pages ...• home.html

• Single / in various directories• Sign: hyperlink to HTML signature page at

bottom• Every page

• Date: creation / modification• Every page; automate

• Status: Stable / under construction

Institute for Visualization and Perception ResearchI VP R 10

© Copyright 1998 Haim Levkowitz

Public access conventions ...

• Server name starts w/ www.

• E-mail alias for comments, tips, requests etc.

• webmaster alias: webmaster@domain-name

Institute for Visualization and Perception ResearchI VP R 11

© Copyright 1998 Haim Levkowitz

Announcing server ...

• Info ...

• Announce to ...

Institute for Visualization and Perception ResearchI VP R 12

© Copyright 1998 Haim Levkowitz

Info ...

• Owner

• Contents

• Status

• URL

Institute for Visualization and Perception ResearchI VP R 13

© Copyright 1998 Haim Levkowitz

Announce to ...

• www-announce@www0.cern.ch

• comp.infosystems.announce

• www-request@info.cern.ch

• whats-new@ncsa.uiuc.edu

Institute for Visualization and Perception ResearchI VP R 14

© Copyright 1998 Haim Levkowitz

Web server maintenance ...

• Updating HTML documents

• Managing log files

• Moving directory structures

• Mirroring documents and servers ...

• HTTP logs and log analysis ...

Institute for Visualization and Perception ResearchI VP R 15

© Copyright 1998 Haim Levkowitz

Mirroring documents and servers ...

• htget Perl script: get HTML non-interactivel from Web server

• Duplicate part or all of another host's dir tree

Institute for Visualization and Perception ResearchI VP R 16

© Copyright 1998 Haim Levkowitz

HTTP logs and log analysis ...

• Two log files (in ServerRoot dir.)

• Error log (logs/error_log)

• Transfer log (logs/access_log)

Institute for Visualization and Perception ResearchI VP R 17

© Copyright 1998 Haim Levkowitz

More features ...

• Adding MIME types ...

• Enabling server-side includes ...

• Automatic directory indexing ...

Institute for Visualization and Perception ResearchI VP R 18

© Copyright 1998 Haim Levkowitz

Adding MIME types ...

• Multipurpose Internet Mail Extensions• E.g., text/plain, text/html, image/gif,

video/quicktime, application/postscript• New: leading x-

• E.g., application/x-http-cgi, text/x-server-parsed-html

• Adding ...

Institute for Visualization and Perception ResearchI VP R 19

© Copyright 1998 Haim Levkowitz

Adding ...• AddType• AddEncoding• DefaultType• E.g., identify HTML documents

• First line of file contains <HTML>• Filename ends with .html• .htm (DOS 8.3 filename)

• AddType text/html htm

Institute for Visualization and Perception ResearchI VP R 20

© Copyright 1998 Haim Levkowitz

Enabling server-side includes ...

• Files• Values of environment variables• Dates, doc sizes, authors, HTML in

multiple docs.• Examples (see my homepage)• Not enabled by default in httpd ...• Security issues ...

Institute for Visualization and Perception ResearchI VP R 21

© Copyright 1998 Haim Levkowitz

Not enabled by default in httpd ...

• Enable: server-wide / per directory• Options Includes (or IncludesNoExec) in access.conf

• Which files get includes inserted• Almost every file

• srm.conf: AddType text/x-server-parsed-html .html• Sparingly

• Define new file extension for files needing processing

• AddType text/html shtml• AddType text/x-server-parsed-html .shtml

Institute for Visualization and Perception ResearchI VP R 22

© Copyright 1998 Haim Levkowitz

Security issues ...

• IncludesNoExec more secure than Includes

• More later