Ibuildings

PHP Deployment with Subversion

Lorna Mitchell

IbuildingsThe PHP Professionals

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About Me

• Lorna Mitchell• PHP Developer/Consultant/Trainer with Ibuildings• ZCE• Member of http://www.phpwomen.org• Personal blog at http://www.lornajane.net

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SVN and Deployment

• Deployment process• Deployment mechanism• Subversion• Other tools

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In The Beginning

• One Developer• Code on PC• FTP / SCP / Upload to live server• It works!

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Early Development Team

• More developers• Development server• Ideally one copy per developer, a testing/staging

server and a live platform

Devarea

Devarea

Devarea

Devarea

Devarea

LIVE

Staging

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Deployment Considerations

• Multiple platforms prompt context-aware configuration

• File permissions may need checking, for example on cache directories

• If the live site has uploaded files stored in the file system, need to preserve this content

• Compile step for initialising compiled templates or populating caches

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Deployment Plan

• A deployment plan is a recipe for moving code• Step-by-step instructions for setting up a new

version of code• Must always be accompanied by a rollback plan• This process should be as automated as possible

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Example Deployment Plan

• Avoid missing steps when putting live

Export from repositoryTar

UntarSet permissionsSwitch symlinks

Upload

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Symlinks

Existing live code

existing

New code version

preparing

Live-site (symlink)

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New code version

ready

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Code Transport

• Copy development code to live• Rsync development code to live• Check out to live and update• Export to live• Patch changes from last live version only – requires

version meta-data

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Commit Hooks

• Subversion can run scripts on given events, called “commit hooks” Pre-commit Post-commit

• Run test suite• Coding standards conformance• Syntax check• No “forgetting” any steps

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Notifications

• Can use the commit hooks to trigger information• Email team

Diff Changes Test coverage/outcomes

• Ticker/big screen• Nabaztag

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Source Control Packages

• Subversion http://subversion.tigris.org • CVS http://www.cvshome.org• GIT http://git.or.cz• Bazaar http://bazaar-vcs.org• Visual Source Safe

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Source Control Clients

• Command line tools• TortoiseSVN: http://tortoise.tigris.org • IDE Plugins: for Zend Studio, Komodo, etc• WebSVN: http://websvn.tigris.org

SFM (Safe For Managers)

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• Trac: http://trac.edgewall.org/

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Source Control Concepts

• Individuals communicate with repository• Keeping place• Collaboration tool• Historic versions

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Collaboration

• Two people operate on different files Changes are combined

• Two people change the same file Changes are merged if changes don't overlap

• Allows teams to easily work on different parts of the system

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Collaboration Example

$greeting = 'hello world';echo $greeting;

$greeting = 'hey people';echo $greeting;

$greeting = 'hello world';print $greeting;

$greeting = 'hey people';print $greeting;

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Conflicts

• Two people edit the same part of the same file Includes both adding a new method to the end of a class

• Subversion will notify you of the conflict and provide: Your most recent version The version from the repository Its best guess at a merge with some notation for where

the overlaps are

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Conflict Example

$greeting = 'hello world';echo $greeting;

$greeting = 'hey people';echo $greeting;

$greeting = 'hi universe';echo $greeting;

$greeting = 'hey people';echo $greeting;

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Conflict Example

<<<<<<< .mine$greeting = 'hi universe';=======$greeting = 'hey people';>>>>>>> .r366echo $greeting;

greeting.php

$greeting = 'hi universe';echo $greeting;

greeting.php.mine

$greeting = 'hey people';echo $greeting;

greeting.php.r366

$greeting = 'hello world';echo $greeting;

greeting.php.r365

• Correct greeting.php and then let Subversion know you have resolved the conflict

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Branching

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Branching Example

version 1.1

version 1.2

development branch

Development done,merge in changes

bug fix

bug fixbackport

Delete extrabranch

trunk

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Tagging Versions

• Source control tools allow you to label releases, called “tags”

• Subversion has one revision number for a whole repository, incrementing on every commit

• CVS has one revision number per file• In either case its nice to have “client preview” or

“release 4.11” as human readable markers

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Repository Structure

• Repository layout choices• Deployment point choices• Affected by process• Dependent on product type

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Cyclic Releases

• Periodic release cycle• Need to maintain existing version• Start developing new version• May need to fix bugs in both versions• Use branching

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Continuous Releases

• Changes to branch• Branch merged to trunk• Can patch changes from branch to trunk for bug

fixes• Deployment from trunk

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Branch Deployment

version 1.1

version 1.2

development branch

testing

deployment!

trunk

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Live Branch

• Changes to branch• Branch merged to trunk• Testing performed on trunk• Changes then patched to live branch• Deployment from live branch

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Live Branch Deployment

development branch

testing

live branch

approved changes

deployment!

trunk

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Database Versioning

• Copying exported versions around Risk losing live data

• Make structure changes to all platforms Put objects in scripts

• Simple patching strategy No direct database operations Numbered patch files in subversion Include patches in script Give database awareness of current patch level Keep an installation script updated with all changes

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Database Rollback

• Write patch file• Also write undo file

-- release.2.0.sql

create table friends(

user_id int not null

friend_user_id int not null

created_date timestamp default current_timestamp not null

);

-- release.2.0.undo.sql

drop table friends;

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DbMorph

• Tool developed by Maggie Nelson• DbMorph, very early version http://sourceforge.net/

projects/dbmorph • Also see Maggie's homepage

http://objectivelyoriented.com • Slides from her talk at php|tek “Keeping Your

Database and PHP in Sync”

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Other Tools

• Phing http://phing.info Project build system based on Apache Ant XML configuration Integration with SVN Available through PEAR

• Phar http://pecl.php.net/package/phar Package management for PHP Like JAR for Java Self-extracting option PECL module

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SVN and Deployment

• Deployment process• Deployment mechanism• Subversion• Other tools

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Ibuildings

Questions?

Lorna Mitchell - lorna@ibuildings.com