Nguyễn Vũ Hưng: Subversion best practices

Subversion 101

2010/10/05

Subversion 101Nguyen Vu Hung

Version Control::
Subversion Best Practices

Nguyen Vu Hung2012/04/11

vuhung16plus(at)gmail.com

2010/10/05


Change History

No

Author

Date

Slides

Details

1

Vuhung

2010/10/04

All

Newly created

2

Vuhung

2010/10/05

-

-

3

Vuhung

2011/01/06

All

Remove private info

4

Vuhung

2012/04/11

All

Convert to odp, add svn tips

2010/10/05


Agenda

Introduction

The Symptoms

Revision Control System overview

Atomic Commits

Revision Explained

Svn History

Overview

Basic usages

Architecture

Components

Installation

Server, client

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Agenda (2)

IDE integration

Command comparison

Workflow

Staging

Staging (Debian)

Repository schema

Resolve Conflicts

Basic Commands

Merging

Revert

Update

Add

Delete

copy

move

mkdir

status

diff

Tips

Examing History

Summary: Basic Commands

Summary: What svn can do?

Summary: Terminologies

Alternatives

References

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The Symptoms

You need files in Recycle Bin

Having more than 2 levels of undo (backup) in a document

vet_20100823.sql, vet_20100824.sql, vet_bak.sql,

Asking someone to send a copy of some files.

FTP transaction died

You dont know what is done yesterday

It works yesterday, but not today.

URGENT: roll back

Failed to manage source code change/merging

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Revision Control System

Revision control, also known as version control, source control or software configuration management (SCM), is the management of changes to documents, programs, and other information stored as computer files. It is most commonly used in software development, where a team of people may change the same files. Changes are usually identified by a number or letter code, termed the "revision number", "revision level", or simply "revision". For example, an initial set of files is "revision 1". When the first change is made, the resulting set is "revision 2", and so on. Each revision is associated with a timestamp and the person making the change. Revisions can be compared, restored, and with some types of files, merged.

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Atomic Commits

None or entireSingle Operation

Revision:per-commit

No inconsistence in large commits

Files within a commit are grouped

0 1 2 3

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Revision Control system

0 1 2 3

As Atomic Changes

Not just change,It is change management

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History

June 2000 - Coding begins.

August 2001 - Subversion becomes self-hosting.

2002 1st release

2004 Feb. Release 1.0.0

2006 Sept. Release 1.4.0

Latest Release: 1.4.6

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Usages

Backing up data

Documentation

ConfigurationManagement

Distributed Development

CR 12

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Architecture

Berkley DB

FSFS

SubversionRepository

Client Interface

Repository Interface

GUI client apps

Commandlineclient apps

ClientLibrary

Working Copy Management Library

Repositoryaccess

DAV

SVN

Local

Apache

mod_dav

mod_dav_svn

svnserve

Internet(Any TCP/IP Network)

Offline SupportUnix/Linux/Windows/Mac OS XWebDav IntegrationSSL LDAP

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Subversion Components

svn (this is what you [client] need)

The command-line client program.

svnadmin

A tool for creating, tweaking or repairing a Subversion repository.

svnserve

A custom standalone server program, runnable as a daemon process or invokable by SSH; another way to make your repository available to others over a network.

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Installation (server)

yum install mod_dav_svn subversion

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Installation (server settings)

[root@vinicorp conf]# cat /etc/httpd/conf.d/subversion.conf

LoadModule dav_svn_module modules/mod_dav_svn.soLoadModule authz_svn_module modules/mod_authz_svn.so

DAV svn

SVNParentPath /svn-repo

# Limit write permission to list of valid users. # Require SSL connection for password protection. # SSLRequireSSL

AuthType Basic AuthName "Vinicorp Subversion Realm" AuthUserFile /etc/svn-auth-conf Require valid-user

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[root@vinicorp conf]# head /etc/svn-auth-conf#vinicorp:pIuFZUS0McheYhoatran:3cYHbUvT9aV0odoancuong:0K3C3IdVJD7VYthuanvd:xJSWLpXNr5/EMhiennb:GHvHoKOG2E1eI

huyenvtt:FySHeMI9u9uvc

trungdq:MB7kxm/IgGMsYthuytp:rw68sUTpnVD7Mthangnv:zSoOwCSdqqcLkphuongdt:o2ZYftrCjq2oM[root@vinicorp conf]# wc -l /etc/svn-auth-conf51 /etc/svn-auth-conf

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[root@conf]# head /etc/svn-auth-conf#xxxxxxxxxx:pIuFZUS0McheYxxxxxxxxxx:3cYHbUvT9aV0oxxxxxxxxxx:0K3C3IdVJD7VYxxxxxxxxxx:xJSWLpXNr5/EMxxxxxxxxxx:GHvHoKOG2E1eIxxxxxxxxxx:FySHeMI9u9uvcxxxxxxxxxx:MB7kxm/IgGMsYxxxxxxxxxx:rw68sUTpnVD7Mxxxxxxxxxx:zSoOwCSdqqcLkxxxxxxxxxx:o2ZYftrCjq2oM[root@conf]# wc -l /etc/svn-auth-conf51 /etc/svn-auth-conf

Create a repo:mkdir /svn-repoCreate an user:htpasswd -c /etc/svn-auth-conf

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[root@ svn-repo]# pwd/svn-repo[root@ svn-repo]# ls -1001.Project1005. Project2006. Project3

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[root@ svn-repo]# pwd/svn-repo[root@ svn-repo]# ls -1001.Project1005.Project2006.Project3

cd /svn-reposvnadmin create 001.Project1chown -R apache.apache 001.Project1service httpd restart

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Installation (client)

TortoiseSVN (Windows)

svn/subversion (Unix/Linux)

svn (Mac OS X)

RapidSVN (cross-platform)

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IDE integration

svn + Eclipse = Subclipse

svn + File Explorer = Tortoisvn

svn + GUI = Rapid svn

svn + vim = svn

Svn + emacs = svn

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Command comparison

Available subcommands:

add

blame

(praise, annotate, ann)

cat

checkout (co)

cleanup

commit (ci)

copy (cp)

delete

(del, remove, rm)

diff (di)

export

help (?, h)

import

info

list (ls)

lock

log

merge

mkdir

move

(mv, rename, ren)

propdel (pdel, pd)

propedit (pedit, pe)

propget (pget, pg)

proplist (plist, pl)

propset (pset, ps)

resolved

revert

status (stat, st)

switch (sw)

unlock

update (up)

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Workflow (admin)

Create a repository (once)

Import or Checkout repository (once)

Update and Check-in

Merge

Commit

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User Workflow

Step 1

Obtain SVN Repository URL from SVN Admin

Ex 1: svn://192.168.x.3/svn-repo/0xx.Proj

Ex 2: http://192.168.x.3/svn-repo/0xx.Proj

Step 2

Checkout SVN module (Repository Copy) to local file system (Working Copy)

Step 3

Update, Commit, Branch, Tag etc...

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Workflow

Update your working copy

svn update

Make changes

svn add

svn delete

svn copy

svn move

Examine your changes

svn status

svn diff

Possibly undo some changes

svn revert

Resolve Conflicts (Merge Others' Changes)

svn update

svn resolved

Commit your changes

svn commit

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Work flow

svn checkoutsvn update

get content

svn addsvn movesvn delete

Make changes

svn status -u

See what was changed in the repository in the meantime

svn update

Update your local copy

svn diffsvn resolved

Merge your changes
Resolve conflicts

svn commit

Submit your changes

105

100

106

SubversionRepository

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Branching

branches

trunk

PC

Root

iPhone

PC branch (vuhung)

branches

trunk

Easy to understandCheap (a little copy)Can be deleted/reanimated

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Branching (2)

branches

trunk

001.SPS

Root

HuyDN

HungNT

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Staging

Staging can be managed via folder structures

tags

Project 1

Root

trunk

Dev

QA

Rel

Development stage (TestServer.biz)

Releases for QA (Test [For the Customer])

Final Releases (ProductionServer.com)

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Real World Example: Debian

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Repository schema

Schema and Access Method

file:/// direct repository access (on local disk)

http:/ access via WebDAV protocol to Subversion-aware Apache server

https:// same as http://, but with SSL encryption.

svn:// access via custom protocol to an svnserve server

svn+ssh:// same as svn://, but through an SSH tunnel.

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Resolve Conflicts

For example, Sally makes changes to the file sandwich.txt in the repository. Harry has just changed the file in his working copy and checked it in. Sally updates her working copy before checking in and she gets a conflict:

$ svn update C sandwich.txt Updated to revision 2.$ ls -1 sandwich.txt sandwich.txt.mine sandwich.txt.r1 sandwich.txt.r2

At this point, Subversion will not allow you to commit the file sandwich.txt until the three temporary files are removed.

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Resolove Conflicts

$ svn commit -m "Add a few more things"

svn: Commit failed (details follow):

svn: Aborting commit: '/home/vuhung/work/sandwich.txt' remains in conflict

If you get a conflict, you need to do one of three things:

Merge the conflicted text by hand (by examining and editing the conflict markers within the file).

Copy one of the temporary files on top of your working file.

Run svn revert to throw away all of your local changes.

Once you've resolved the conflict, you need to let Subversion know by running svn resolved. This removes the three temporary files and Subversion no longer considers the file to be in a state of conflict.[6]

$ svn resolved sandwich.txt

Resolved conflicted state of 'sandwich.txt'

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Merge

We both update the same file at the same time. What happens?

Update tells me there is a conflict

You checked yours in first

I have to merge the two updates together.

Before checking in

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Merge Conflicts by hand

Merging conflicts by hand can be quite intimidating the first time you attempt it, but with a little practice, it can become as easy as falling off a bike.

Here's an example. Due to a miscommunication, you and Sally, your collaborator, both edit the file sandwich.txt at the same time. Sally commits her changes, and when you go to update your working copy, you get a conflict and you're going to have to edit sandwich.txt to resolve the conflicts. First, let's take a look at the file:

$ cat sandwich.txtTop piece of breadMayonnaiseLettuceTomatoProvolone> .r2Creole MustardBottom piece of bread

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Merging: Revert

Punting: Using svn revert

If you get a conflict, and upon examination decide that you want to throw out your changes and start your edits again, just revert your changes:

$ svn revert sandwich.txtReverted 'sandwich.txt'$ ls sandwich.* sandwich.txt

Note that when you revert a conflicted file, you don't have to run svn resolved.

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Checkin

Check-in - Update the central repository to match your local files

Always update before checking in (svn enforces this)

Always test with the latest update before checking in (not enforced)

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commit

svn commit command sends all of your changes to the repository. When you commit a change, you need to supply a log message, describing your change. Your log message will be attached to the new revision you create. Log message can be set in command line using the --message (or -m) switch:

$ svn commit -m "Corrected number of cheese slices."

Sending sandwich.txt Transmitting file data . Committed revision 3.

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checkout

$ svn checkout http://192.168.x.3/svn-repo/0xx.ProjA 0xx.Proj/SourceCodeA 0xx.Proj/Document

Checked out revision 1.

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update

Update - Updates the local files to match the central repository

NOTE: Change to the working folder (the local folder that you have checked out from the repository into your local file system)

svn update U SourceCode//public/images/basic_title_bg.gif

U SourceCode//public/images/btn_search.gif Updated to revision 2.

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svn add

svn add foo

Schedule file, directory, or symbolic link foo to be added to the repository. When you next commit, foo will become a child of its parent directory. Note that if foo is a directory, everything underneath foo will be scheduled for addition. If you only want to add foo itself, pass the --non-recursive (-N) option.

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svn delete

svn delete foo

Schedule file, directory, or ymbolic link foo to be deleted from the repository. If foo is a file or link, it is immediately deleted from your working copy. If foo is a directory, it is not deleted, but Subversion schedules it for deletion. When you commit your changes, foo will be removed from your working copy and the repository.

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svn copy

svn copy foo bar

Create a new item bar as a duplicate of foo and automatically schedule bar for addition. When bar is added to the repository on the next commit, its copy history is recorded (as having originally come from foo). svn copy does not create intermediate directories.

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svn move

svn move foo bar

This command is exactly the same as running svn copy foo bar; svn delete foo. That is, bar is scheduled for addition as a copy of foo, and foo is scheduled for removal. svn move does not create intermediate directories.

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svn mkdir

svn mkdir blort

This command is exactly the same as running mkdir blort; svn add blort. That is, a new directory named blort is created and scheduled for addition.

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svn update (2)

Update working copy

Update all files and directories to the most current version

$svn update

Go to a particular older revision for all files and directories

$% svn update r 1345

I want an even older version of svn-doc.el

$% svn update r 999 FolderName

Update output and what it means

U `foo'

File `foo' was (U)pdated (received changes from the server.)

A `foo'

File or directory `foo' was (A)dded to your working copy.

D `foo'

File or directory `foo' was (D)eleted from your working copy.

R `foo'

File or directory `foo' was (R)eplaced in your working copy; that is, `foo' was deleted, and a new item with the same name was added. While they may have the same name, the repository considers them to be distinct objects with distinct histories.

G `foo'

File `foo' received new changes, but also had changes of your own to begin with. The changes did not intersect, however, so Subversion has mer(G)ed the repository's changes into the file without a problem.

C `foo'

File `foo' received (C)onflicting changes from the server. The changes from the server directly overlap your own changes to the file. No need to panic, though. This overlap needs to be resolved by a human (you).

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svn status

svn status

A Daily/20100927/chuyen.txt # file is scheduled for addition

C Daily/20100824/iPadQA.xl # file has textual conflicts from an update

D Daily/20100927/chuyen.lrc # file is scheduled for deletion

M Daily/20100927 # the content in Daily/20100927 has local modifications

A item The file, directory, or symbolic link item has been scheduled for addition into the repository.C item The file item is in a state of conflict. That is, changes received from the server during an update overlap with local changes that you have in your working copy. You must resolve this conflict before committing your changes to the repository.D item The file, directory, or symbolic link item has been scheduled for deletion from the repository.M item The contents of the file item have been modified.

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Svn diff

[vuhung@ 20100927]$ svn diff .Index: chuyen.lrc===================================================================--- chuyen.lrc (revision 166)+++ chuyen.lrc (working copy)@@ -5,15 +5,15 @@ [00:15.83]chieu ngoai o, gio khe dua toc em [00:26.51]Cong cong con duong uon quanh. -[00:30.71]chieu dao pho, chieu mang chut huong thanh binh [00:46.72]Thuong anh yeu anh em uoc mo. -[01:01.23]Uoc mo nho be trong doi +[01:01.23]Uoc va mo nho be trong doi [01:16.11]UOc mo cho tinh yeu len hat sac xuan +[01:16.11]UOc mo cho tinh yeu len hat sac xuan [01:21.19]Uoc mo la la tren canh [01:27.07]Nguoc mat thay bao giac mo. @@ -44,4 +44,4 @@ [03:53.07]??c m? nh? be trong ??i [03:58.84]Ng??c m?t th?y bao gi?c m?.-[04:10:10]\ No newline at end of file+[04:10:10]

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Tips

Commit small

Commit often

Comment, comment, comment

Change set

svn update (online) vs. svn status (offline)

svn log: who && what

svn merge = you + me.

svn update and test before commit

Work on local copy

Solve the conflicts

Do not commit hidden, un-related, temporary files.

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Examining History

svn log

svn diff

svn history

svn list

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Summary: Basic Commands

svn add Add files, directories, or symbolic links.

svn copy Copy a file or directory in a working copy or in the repository.

svn mkdir Create a new directory under version control.

svn delete Delete an item from a working copy or the repository.

svn export Export a clean directory tree.

svn import Commit an unversioned file or tree into the repository.

svn move Move a file or directory

svn diff Display the differences between two paths.

svn merge Apply the differences between two sources to a working copy path.

svn resolved Remove conflicted state on working copy files or directories.

svn revert Undo all local edits.

svn status Print the status of working copy files and directories.

svn update Update your working copy.

svn checkout Check out a working copy from a repository.

svn commit Send changes from your working copy to the repository.

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Summary: What svn can do?

Backup and Restore. Files are saved as they are edited, and you can jump to any moment in time. Need that file as it was on Feb 23, 2007? No problem.

Synchronization. Lets people share files and stay up-to-date with the latest version.

Short-term undo. Monkeying with a file and messed it up? (Thats just like you, isnt it?). Throw away your changes and go back to the last known good version in the database.

Long-term undo. Sometimes we mess up bad. Suppose you made a change a year ago, and it had a bug. Jump back to the old version, and see what change was made that day.

Track Changes. As files are updated, you can leave messages explaining why the change happened (stored in the VCS, not the file). This makes it easy to see how a file is evolving over time, and why.

Track Ownership. A VCS tags every change with the name of the person who made it. Helpful for blamestorming giving credit.

Sandboxing, or insurance against yourself. Making a big change? You can make temporary changes in an isolated area, test and work out the kinks before checking in your changes.

Branching and merging. A larger sandbox. You can branch a copy of your code into a separate area and modify it in isolation (tracking changes separately). Later, you can merge your work back into the common area.

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Summary: Terminologies (Basic Setup)

Repository (repo): The database storing the files.

Server: The computer storing the repo.

Client: The computer connecting to the repo.

Working Set/Working Copy: Your local directory of files, where you make changes.

Trunk/Main: The primary location for code in the repo. Think of code as a family tree the trunk is the main line.

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Summary: Terminologies (Basic Actions )

Add: Put a file into the repo for the first time, i.e. begin tracking it with Version Control.

Revision: What version a file is on (v1, v2, v3, etc.).

Head: The latest revision in the repo.

Check out: Download a file from the repo.

Check in: Upload a file to the repository (if it has changed). The file gets a new revision number, and people can check out the latest one.

Checkin Message: A short message describing what was changed.

Changelog/History: A list of changes made to a file since it was created.

Update/Sync: Synchronize your files with the latest from the repository. This lets you grab the latest revisions of all files.

Revert: Throw away your local changes and reload the latest version from the repository.

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Summary: Terminologies (Advanced Actions)

Branch: Create a separate copy of a file/folder for private use (bug fixing, testing, etc). Branch is both a verb (branch the code) and a noun (Which branch is it in?).

Diff/Change/Delta: Finding the differences between two files. Useful for seeing what changed between revisions.

Merge (or patch): Apply the changes from one file to another, to bring it up-to-date. For example, you can merge features from one branch into another. (At Microsoft this was called Reverse Integrate and Forward Integrate)

Conflict: When pending changes to a file contradict each other (both changes cannot be applied).

Resolve: Fixing the changes that contradict each other and checking in the correct version.

Locking: Taking control of a file so nobody else can edit it until you unlock it. Some version control systems use this to avoid conflicts.

Breaking the lock: Forcibly unlocking a file so you can edit it. It may be needed if someone locks a file and goes on vacation (or calls in sick the day Halo 3 comes out).

Check out for edit: Checking out an editable version of a file. Some VCSes have editable files by default, others require an explicit command.

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Alternatives

Historical

RCS (Revision Control System)

Distributed model

Bazzar (python-based, Canonical supported)

Git (Perl, C, shell based)

Open source

CVS (Concurrent Versions System)

CSVNT (for Windows [NT])

Proprietary

CMVC (Configuration Management Version Control) (IBM)

Visual Source Safe (Microsoft)

Visual Studio Team System (Microsoft)

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References

Polarion subversion tutorial

http://www.slideshare.net/intellibitz/subversion-user-guide

http://www.ericsink.com/scm/source_control.html

http://betterexplained.com/articles/a-visual-guide-to-version-control/

Photographer: jscreationzs http://www.freedigitalphotos.net/images/Browns_and_Creams_g332-Question_Mark__p17549.html

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Version Control::
Subversion Best Practices

Nguyen Vu Hung2012/04/11

vuhung16plus(at)gmail.com

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2012/04/11

Subversion Best PracticesNguyen Vu Hung

Nguyễn Vũ Hưng: Subversion best practices

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