Building A Subversion Server

1. Building A Subversion Server Version Control for Your Robot Software By Hugh Meyer FRC Team 1741 Red Alert Robotics Greenwood Indiana October 29, 2011

2. Purpose • The purpose of this session is to provide a comprehensive overview of the process to build and use a subversion server by supplying you enough information to implement your own server and expose sources of additional information for more detailed help. • By Hugh Meyer FRC Team # 1741

3. Introduction to Subversion • What it is and why we need it • The Problem of File Sharing • Memory Stick Nightmares • Ultimate Backup System • Giant edit undo button

4. What is Subversion and why do we need it • Subversion is software that is designed to help programmers keep track of different changes or versions of code • It allows several people to share and work on the same code at the same time • It simplifies the process of merging code from different developers

5. The Problem of File Sharing • When two or more people need to modify the same file at the same time on different computers • How to prevent users from over writing each others changes • There are two ways to solve this • The Lock-Modify-Unlock Solution • The Copy-Modify-Merge Solution

6. Memory Stick Nightmares • Students tend to share files by memory sticks so it is easy for them to share program code this way. • As they develop code the number of different files, that are really the same file modified over and over increases beyond control very quickly. • Tracking who has the latest version is very difficult and merging changes from different users is very time consuming and error prone.

7. Ultimate Backup System • Have you ever lost work because your computer crashed? • It is not a matter of if you computer disk crashes but when!

8. Giant edit undo button • Have you ever lost work because you saved a file that you changed and wished you had the previous file back? • Edit undo is great, but some times it is only good to a point.

9. Computer Hardware • Get a computer to build your server • If you have the funds get the biggest hard drive you can • If you have the funds get the fastest CPU you can • If you have the funds get the most memory you can • If you don’t have funds don’t worry! Just about anything will do!

10. Machine Requirements • Generally speaking not very demanding. • OS needs about 200 meg of disk space. • Memory required is 8 meg. • CPU is 386 and up. • More is always better…

11. Ideas for Cheap Machines • Talk to your school network administrator • Talk to your sponsors IT department • Talk to you church IT administrator • Ask parents of students

12. Load and Configure Operating System NetBSD • Download ISO image and burn boot disk • Run the install process • Learn basic command for VI text editor (Google is your friend) • Setup IP address, gateway, DNS servers • Connect system to the Internet • Test connection • Install Package System • Setup svn user and svn_user group • Configure any firewalls you are behind to open svn port # 3690

13. Download ISO Image and Burn Boot Disk • Go to the NetBSD website. • Click on the download NetBSD link. • I like to download the ISO image and burn a bootable CD. • I generally will download from the master site in California. • Use this file and your favorite disk burning software to make a bootable disk. • In Nero the command is “burn image” under the “recorder” menu item. • This process is not the same as burning a data disk.

14. Running the Install Process • Be sure your computer will boot from the CDrom drive. You may need to adjust a setting in your cmos. • Follow the wizard prompts. The defaults will nearly always work and are usually the best choices. • Reboot the machine. • Review the afterboot man page. It provides a check list of stuff to complete after a new install.

15. Learn Some Basic OS Commands • Command cd in this context is change directory • “cd /” puts you at the root level • Command “cd etc” is where most files you need to change will be • Command ls gives a listing of files • Command pwd prints working directory • Command dmesg shows boot messages that go so fast you miss them

16. Learn Basic OS Commands • Man pages are built in help • apropos searches the man pages • The pipe ‘| more’ function is handy • The documentation on the NetBSD website is good • How to documents on the NetBSD website are nice

17. Learn Basic Commands for VI Text Editor • Initiate the editor with the command “vi filename” of the file you want to edit • Command “vi rc.conf” edits a primary configuration file • J moves down, k moves up, l moves left, h moves right • Command :x exits and saves • See resource page for more…

18. Setup IP address, gateway, DNS servers • Edit /etc/rc.conf file to insert ifconfig line and defaultroute gateway. • Ifconfig ex0 inet xx.xx.xx.xx netmask 255.255.255.xx using the IP address and netmask for your internet connection. • defaultroute=“xx.xx.xx.xx” • Edit /etc/resolv.conf to include your ISP namservers • nameserver xx.xx.xx.xx

19. Connect System to the Internet • Plug in network cable to your network device • Be sure it is 100 mbps or faster if possible • Check link lights

20. Test connection • Ping your router • ‘ping ww.xx.yy.zz’ • Ping your name servers • Do a name lookup to be sure DNS is working “nslookup google.com” • If these three work you can count it good

21. Install NetBSD Package System • I like to use sup to install the package system. It takes longer to download initially, but after that it only downloads the updates files and will automatically handle deleting old files. The following commands will do the job. • mkdir /etc/supfiles /usr/sup • cp /usr/share/examples/supfiles/sup.netbsd.org /etc/supfiles/coll.list

22. Install NetBSD Package System • Edit the /etc/supfiles/coll.list, and comment out (add a # to the start) all lines except the block of two lines that start “current release=pkgsrc’ • Run sup to update pkgsrc with the command ‘sup –s –v’ • Be aware this will take a while. I let it run at night and it is done in the morning.

23. Setup svn user and svn_user group • ‘useradd –m svn’ • ‘groupadd svn_user’ • ‘usermod –G svn_user svn’ • ‘passwd svn’

24. Define Repository Files Location • Create the directory structure where you want your repository located as root • ‘mkdir /usr2’ • ‘cd /usr2’ • ‘mkdir repos’ • Change owner to svn ‘chown svn /usr2’ • ‘chown svn /usr2/repos’

25. Set User and Group • Change group to svn_user • ‘chgrp svn_user /usr2 • ‘chgrp svn_user /usr2/repos’ • Verify that directories are set to correct user and group with the ‘ll’ command

26. Configure Any Firewalls You Are Behind to Open SVN Port # 3690 • Subversion uses port 3690 • This port must be open if you are behind any fire walls • If this is on a school network then you will need your network administrator to do this • If you are on Comcast or AT&T or similar service then you may need to log into your router, or hopefully the port will be open by default • You MUST have a static IP address

27. Load and Configure Subversion • Download, build, and install subversion using the package system • Test your new subversion install • Setup inetd to launch subversion on incoming request using svnserve • Setup host allow and deny files to control access if desired • Create repository using svnadmin create command • Setup passwd and other conf files

28. Download, Build, and Install Subversion Using the Package System • Be sure you are logged in as root • Easiest way to install is to use the NetBSD package system. • Change directory to the package folder for subversion • ‘cd /usr/pkgsrc/devel/subversion’ • ‘make fetch-list | sh’ • This will download all dependencies

29. Download, Build, and Install Subversion Using the Package System • ‘make’ • ‘make install’ • ‘make clean’ • ‘make clean CLEANDEPENDS=YES’

30. Test Your New Subversion Install • Test the installation by entering the command ‘svn ? | more’ You should get a response of commands. • Enter command ‘svnadmin help’ you should get list of commands. • If these work you are good to go.

31. Setup inetd • Inetd is a process that looks for incoming connections on the server and launches the appropriate executable depending on the requested service. • The /etc/inetd.conf file must be updated to indicate what to do with a subversion request. • Edit the /etc/inetd.conf file • ‘svn stream tcp nowait svn /usr/pkg/bin/svnserve svnserve –i –r /usr2/repos’ • Restart inetd ‘/etc/rc,d/inetd restart’

32. Setup Host Allow and Deny Files to Control Access If Desired • If you are concerned about security you can create two files that will tell inetd to allow or deny certain requests. • Create an /etc/hosts.allow file • Insert the following lines • ‘svnserve: ALL’ or ‘svnserve: xx.xx.xx.xx

33. Setup Host Allow and Deny Files to Control Access If Desired • Create a /etc/hosts.deny file • ‘ALL:ALL’ or any you know you want to keep out. • I have the svn open so students can access it from home, but I do restrict other services like telnet to only allow connections from my home, the school, and my work. • See the man page hosts_access(5) for more information on this feature.

34. Create Repository Using svnadmin Create Command • You should be logged in as user svn • Change directory to the location you created earlier for your repository files • I use /usr2/repos • Use the svnadmin command to create your repostiory • ‘svnadmin create YouRepoName’ • Change directory to the new location and you should have several directories with files in them

35. Setup passwd and Other Conf Files • Use command ls and you should see a folder ‘conf’ • cd to the conf folder • Modify the svnserve.conf file to set access like you want and activate the password file • The file explains what things do, so read and follow the instructions • Modify the password file by adding the users you want to have access to your repository • Your server setup is now complete

36. Create and Initialize Client Working Environment • Load Client Tools • TortoiseSVN • Subeclipse • Subersion command line tools • SlikSVN

37. TortoiseSVN • Integrated solution for Windows • Implemented as a shell extension • Works with any file type • Visually shows you modified files with icon overlays • Download from: http://tortoisesvn.net/

41. Subeclipse • Integrated solution for Eclipse • Used by the Wind River Workbench • Instructions for installation are in chapter 4 of the FRC Software Guide

43. Subversion Command Line Tools • Useful for compilers • Useful to IDEs that need to interface to the repository

44. SlikSVN • Command tool used by Wind River Workbench • Instructions for installation are in chapter 4 of the FRC Software Guide

45. Using Subversion • Initial folders and files import • Checkout working copy • Commit changes made to working copy • Update working copy to merge changes others have made

46. Initial Folders and Files Import • Setup branches, tags, and trunk folders • Import the files you want in your trunk folder • DELETE Your Local Copy!! (or just move it somewhere else)

48. Checkout Working Copy • Use appropriate tool to do initial checkout • Test the working copy by compiling to be sure everything works

50. Committing Working Copy • Select commit option • Dialog box will pop up showing what it plans to do • Read this box carefully to be sure it is what you want to happen • It will show new files and ask if you want to add them or ignore them