1	Assembling Web Development Environments with Perforce Stephen Vance Perforce User Conference 2001
2	Once Upon A Time … Experiences from Consulting for Web companies Involvement with Internet Start-up Problem-solving from personal interest Internet start-up is main storyline. Of course, names changed. And now, on with our story.
3	The Characters Me: “I can’t let chaos ruin us” The CFO: “We’re on a tight venture budget” The CTO: “I can develop that in two hacks” The Marketing Guy: “I can’t live without my Mac” The Sub-contractor: “We do what we do”
4	The Case for SCM in Web Development Many disciplines converging in one medium Programmers HTML designers Advertising executives Marketers Many skill levels from novice to expert Large-scale sites are still driven by custom-coded solutions and large numbers of contributors
5	In The Beginning … There was the void. a.k.a. a start-up with funding and no developers And then he said, “Let them have options” and product development commenced. Against better judgment we started hacking out of a common directory tree
6	Aaaarrrrgh! And as one might expect, some code was irretrievably flattened at 3:00 a.m. by two people working on the same file. After some “discussions” with the CTO and the CFO, Perforce was purchased.
7	The Web Site Conundrum Each developer has his own workspace But there is still only one Web server Although source changes are safe against multiple authors, there is only one testing environment Until …
8	Virtual Hosts IP- or name-based IP-based virtual hosting has shortcomings Name-based virtual hosting addresses these shortcomings
9	Name-based Virtual Hosts Server distinguishes Web sites based on name in Host header DNS wildcards avoid need for DNS reconfiguration Apache configuration handles the rest GET / HTTP/1.1 Host: www.vance.com
10	Visualizing Virtual Hosts
11	Enter The Marketing Guy Technically savvy, but non-developer Rejected disk sharing technologies No Mac solution for non-developers Used Windows, but Hated it Required logging in to sync virtual host Until …
12	P4Web to the Rescue P4Web is a Perforce-specialized Web server Provides GUI on any platform with a browser Runs on almost any platform supported by Perforce Allows management and viewing of Web content in Perforce
13	P4Web Configurations
14	The Next Challenge The Marketing Guy is happy. Then he announces that he has hired a sub-contractor to do the Web design. Quite reasonably, the sub-contractor doesn’t feel he needs to learn Perforce to fulfill the contract.
15	Easy FTP Integration Web design tools support ftp Put sub-contractor work on its own branch Create a client with “allwrite” option Create virtual host with document root of <client root>/htdocs Tell sub-contractor to set ftp location to <client root>/htdocs Populate /cgi-bin if necessary Use Tech Note #2 techniques when sub-contractor notifies of updates
16	Improved Integration Using P4FTP P4FTP is Perforce FTP server where session is a submission Isolate work to a branch Excellent solution, but two drawbacks Content only transiently populates disk, so not fit to work with virtual host for viewing Each ftp user consumes a Perforce license and only uses a single client workspace
17	Where We Are Virtual hosting allows multiple Web servers on minimal hardware P4Web allows browser-based use of Perforce client functionality with viewing of static content FTP and P4FTP allow smooth integration with Web design tools However, we still have to sync a Unix client to fully view content
18	Viewing Content with WebKeeper What? Apache module allowing direct viewing of content from Perforce depot Open source project in the Perforce public depot Recently enhanced Who? Originally authored through Perforce I was recently designated curator Where? Info at http://public.perforce.com/public/perforce/webkeeper/index.html public.perforce.com:1666://public/perforce/webkeeper/…
19	How WebKeeper Works
20	WebKeeper Installation Instructions in README.WEBKEEP in Perforce public depot Builds either statically or as loadable module Builds either using full Apache source tree or using apxs with Red Hat apache-devel. Built and tested on FreeBSD and Linux. Other platforms on request Plan to add binary loadable modules for FreeBSD and Red Hat Linux to public depot.
21	Basic WebKeeper Configuration <VirtualHost *> ServerName site1.dev.vance.com <IfModule mod_webkeep.c> WebKeepPort perforce.vance.com:1666 WebKeepUser steve WebKeepPasswd mypassword WebKeepDirectoryIndex index.html WebKeepAlias / //depot/dev/site1/htdocs/ </IfModule> </VirtualHost> WebKeep directives replace DocumentRoot WebKeepDirectoryIndex should correspond to Apache DirectoryIndex WebKeepAlias maps Web root to Perforce depot IfModule makes configuration portable
22	Why Do We Need More? In two words, “Dynamic Content” Text-based Server-side includes (SSI) PHP Perl ASP JSP Server-processed XML and XSLT Binary C/C++ CGI EJB Servlets
23	Text-based Dynamic Content <IfModule mod_webkeep.c> WebKeepPort perforce:1666 WebKeepUser perforce_user WebKeepDirectoryIndex index.html WebKeepAlias / //my_client/htdocs/ WebKeepClient my_client WebKeepSync On WebKeepRefresh //my_client/include/… </IfModule> WebKeepClient gives a client spec WebKeepSync tells WebKeeper to sync the files to the client for Apache WebKeepRefresh (added after paper) always refreshes include directory
24	Adding CGI Support <VirtualHost *> ServerAdmin webmaster@vance.com ServerName site1.dev.vance.com DocumentRoot /usr/local/dev/steve/htdocs ScriptAlias /cgi-bin /usr/local/dev/steve/cgi-bin <IfModule mod_webkeep.c> WebKeepPort perforce.vance.com:1666 WebKeepUser steve WebKeepDirectoryIndex index.html WebKeepAlias /cgi-bin/ //depot/dev/steve/cgi-bin/ WebKeepAlias / //depot/dev/steve/htdocs/ WebKeepClient my_client WebKeepSync On </IfModule> </VirtualHost> DocumentRoot re-introduced for file access ScriptAlias tells Apache which content to treat as CGI scripts New WebKeepAlias tells WebKeeper how to populate the CGI directory WebKeeper handles aliases in the order presented in the configuration, so the CGI alias must come first
25	Compiled Web Elements Web elements that Require compilation before being sent to browser Require compilation before executing on server Examples Java applets C/C++ CGIs Java Servlets Enterprise JavaBeans
26	Compiled Element Issues Platform dependence C/C++ and Java with JNI are platform-dependent Java without JNI and scripts are independent Impacts location of development workspaces Deployment location Combines with platform to constrain choices
27	Supporting Compiled Elements C/C++ CGIs Compile on server or like platform Target or copy to /cgi-bin on virtual host Java applets Compile on any platform (JNI usually non-issue) Target or copy to virtual host EJBs and Servlets Compile on any platform JRE compatibility Target or copy to server’s <app-path>/WEB-INF/classes java –d <app-path>/WEB-INF/classes Some.class Manually update deployment descriptors if necessary Setup up application server to dynamically reload classes
28	Web Site Deployment Perforce can be used to deploy Web sites WebKeeper not advised for production sites Additional DNS lookups and network requests Potential security hole through firewall Large Perforce operations result in Web site unavailability Syncing is advised method
29	Deployment Techniques Check in binaries Maintain two document trees Ensures atomicity of deployment Reduces timing demands for deployment Method One is live Deploy to the non-live Switch Analogous to graphics double-buffering
30	Web Site Double-Buffering
31	Advanced Deployment Coordinating deployment to and switchover in server farm Deploying to multiple hosting centers Sub-dividing content space for partial deployment See P4UC00 presentation by David Markley and Scott Money of Lycos, Inc. for ideas on large-scale deployment
32	Branching for Web Content Different from branching for traditional software products Shorter cycles Smaller functional change sets More evolutionary More continuous Typically two- or three-tiered approach Development mainline QA codeline Possible release codeline
33	WCM Branching
34	For More Info Additional info in paper on Installing WebKeeper Whether and when to archive binaries Handling shared resources like databases Managing Apache configurations Product and literature references
35	Future Directions Expand application server integration J2EE servers Zope Expand large-scale deployment strategies Enhance WebKeeper See http://public.perforce.com/public/perforce/webkeeper/index.html Started basic authentication before conference based on Chris Seiwald’s work Mass virtual hosting support Add binary modules to depot Support Apache 2.0 Miscellaneous smaller items
36	Conclusion Perforce + Open-Source Software + Best Practices = Effective Web Development Management As always, consider the needs when implementing solutions Hopefully, this material gives you the information to consider wisely