Subversion (SVN)

This is a step-by-step guide for dummies on how to configure SVN from scratch.

Setting up a Subversion - SVN service (deamon)

Use YUM (or your distribution package manager, if any) to make sure that Subversion (SVN) is installed on your system. If not, install it.

SVN is a network service, so it needs to be accessed from network. Bearing this in mind, you should make sure that your system firewall is allowing traffic before you start any service configurations.

Set up your network (SVN ports)

You should set up your network first. If you don't, you might have the correct SVN service configuration, and you'll be trying to find where it's failing not realizing it's a network configuration problem.

Testing IP reach

First, test if both machines (SVN repository server and SVN client) can reach each other.

Ping the SVN server IP from the SVN client (ping aaa.bbb.ccc.ddd), and ping the SVN client from the SVN server.

Set up both firewalls

Open the following ports at the firewall on both machines (outbound at the SVN client, and inbound at the SVN server):

This is what's mostly used. But IANA has listed a somewhat different set of ports:

svn 3690/tcp Subversion

svn 3690/udp Subversion

Source: http://www.iana.org/assignments/port-numbers

Create the SVN user.

A system account is needed, to run the SVN Server and protect files.

Therefore, an user and group must be created for SVN, if they don't exist already.

Check if you have a SVN user at /etc/passwd and a group at /etc/group.

Otherwise, create where missing.

Suggested values:

• • User

  • Username: svn

    • Full Name: SVN Owner

    • Login Shell: /sbin/nologin (system user not for login)

    • Home: /home/svn

    • ID: 56

  • Group

    • Group Name: svn

RED: The user name that you choose here will influence the next configurations.

Add SVN as a service (xinetd)

Now, if we want SVN to be up and ready automatically after an eventual reboot, we need to set up SVN as a service.

To do this, we must add SVN to XINETD.

Go to /etc/xinetd.d and check if you have already a file named svn, otherwise we must create one.

The file content should be something like:

# Begin /etc/xinetd.d/svn

service svn

{

disable = no

port = 3690

socket_type = stream

protocol = tcp

wait = no

user = svn

server = /usr/bin/svnserve

server_args = -i -r /var/svn/repos

}

# End /etc/xinetd.d/svn

See attached file below.

RED: Remember the user name created before. That user name must match the one after user=. Also be warned that the repository location chosen at server_args will influence next configurations.

Check if xinetd service is running, and if svn is selected to run. If not, select it and restart xinetd.

Set up a repository

Now that the SVN Server (svnserve) is up and running, we need a repository to connect to.

Let's set up one...

Create the repository

Create a repository named garbage, where you can grasp the ways of SVN.

To create this repository execute the following command:

• • svnadmin create /var/svn/repos/garbage

RED: Remember that you specified repositories location at /var/svn/repos at the previous configuration.

Set the correct file system permissions

All files created by the command executed at the previous step will have owner, group and permissions set to the user used to execute the command.

For security purpose, all repository files should be accessible only to the SVN Server (svnserve) which is running as svn user. So all repository files must be owned by svn, with group svn and with read and write permissions to svn user, and to svn group as needed.

To achieve this, execute the following commands:

• • find /var/svn -exec chown svn '{}' \;

  • find /var/svn -exec chgrp svn '{}' \;

  • find /var/svn -exec chmod u+rw '{}' \;

  • find /var/svn -exec chmod go= '{}' \;

Or:

• • find /var/svn -exec chown svn '{}' \;

  • find /var/svn -exec chgrp svn '{}' \;

  • find /var/svn -exec chmod ug+rw '{}' \;

  • find /var/svn -exec chmod o= '{}' \;

Or whatever permissions you need.

RED: Remember that those values depend on previous configurations.

You can also create a shell script, a batch of some sort, that you can execute every time you create a new repository.

Something like:

#!/bin/bash

find /var/svn -exec chown svn '{}' \;

find /var/svn -exec chgrp svn '{}' \;

find /var/svn -exec chmod u+rw '{}' \;

find /var/svn -exec chmod go= '{}' \;

Or, if you'd like to run this only for a specific repository (repository name as an argument on script call):

#!/bin/bash

if [ "$1" = "" ]

then

echo "Usage: $0 repository_name"

else

find /var/svn/repos/$1 -exec chown svn '{}' \;

find /var/svn/repos/$1 -exec chgrp svn '{}' \;

find /var/svn/repos/$1 -exec chmod ug+rwX '{}' \;

find /var/svn/repos/$1 -exec chmod o= '{}' \;

fi

A sample file is attached below.

Give access to the users

Now we need to configure users' repository access.

Configuration files for this can be found at /var/svn/repos/garbage/conf. That is to say that user access will have to be set up for each repository. If you'd like to have a single user configuration for multiples repositories, you'll need a different set of configuration files.

RED: Path depends on previous configurations.

At this directory you'll find the following 3 text files (with examples inside):

• • authz

  • passwd

  • svnserve.conf

The included examples are self explanatory, but I'll add something even more explicit.

passwd

[users]

harry = harryspassword

sally = sallyspassword

greta = gretaspassword

linda = lindaspassword

This is the simplest file of the bunch. It just stores user names and associated passwords.

List here the SVN users and respective passwords.

authz

[groups]

admins = harry

analysts = harry, sally

programmers = greta, linda

users = @admins, @analysts, @programmers

[/]

* =

@users = r

@admins = rw

[/docs]

@analysts = rw

[/source]

@programmers = rw

sally = rw

This defines user's groups and their access to directories inside this (where the files are) repository.

svnserve.conf

[general]

#anon-access = read

anon-access = none

auth-access = write

password-db = passwd

authz-db = authz

realm = GarbageRealm

This configuration will not allow unidentified users to browse the repository, will allow up to write to identified users, will use the passwd and authz files at the conf directory for user and access rights database, and identifies this access configuration as GarbageRealm.

You can now test connections from your SVN Client.

Common access

You can have a common access definitions to your repositories.

To achieve this, place the passwd and authz files outside your repository directory structure. A good place to store these files is at the directory where you're storing your repositories. At the example above, should be /var/svn or /var/svn/repos directory.

The svnserve.conf should now point to the passwd and authz new locations. The realm should have the same value on all svnserve.conf that point to the same passwd and authz files, so clients are aware that stored identification pairs (user and password) should work for those repositories.

The authz can now have distinct permissions set for different repositories.

Example:

[groups]

admins = harry

analysts = harry, sally

programmers = greta, linda

users = @admins, @analysts, @programmers

[repository1:/]

* =

@users = r

@admins = rw

@analysts = rw

[repository2:/]

* =

@users = r

@admins = rw

@programmers = rw

[repository3:/docs]

@analysts = rw

[repository4:/source]

@programmers = rw

sally = rw

Import files

If you already have a directory structure and files for your project, place a trunk-branches-tags directory structure around that project structure, and import it into your repository by issuing the following command:

• • • svn import -m "Initial import" /dir/files svn://rep.server.ip/rep_name

Upgrading Subversion

The following was tested only under CentOS 5.4 (Red Hat) with the svn protocol (no http):

• 1. Stop the xinetd service (responsible for the svnserve) by issuing the command:

     • /sbin/service xinetd stop

  2. Uninstall (using YUM or RPM) the version of Subversion that is shipped with CentOS (or Red Hat).

  3. Download the appropriate Subversion client and server RPM files from http://www.collab.net/downloads/subversion/redhat.html.

  4. Install the client and server RPM's.

  5. Edit the file /etc/xinetd.d/svn and...

     • Replace:

     • /usr/bin/svnserve

     • With:

     • /opt/CollabNet_Subversion/bin/svnserve

  6. Upgrade the repositories by issuing the command (single line) for each repository:

     • /opt/CollabNet_Subversion/bin/svnadmin upgrade /var/svn/repos/repository_name

1. Don't forget to reset permissions, as when setting up a new repository (this upgrade might create new files and directories).

2. Start the xinetd service to launch the new svnserve version.

Should be up and running.

RED: Path depends on previous configurations.

Synchronizing repositories

If we set up two (or more) svn servers, and want repositories to be on both (or more) servers, then we want them to be synchronized.

A few easy steps, at the destination server, can accomplish this:

• 1. Create a new svn repository:

     • svnadmin create /var/svn/repos/repository_name

  2. Allow properties changes to occur:

     • echo "#!/bin/bash" > /var/svn/repos/repository_name/hooks/pre-revprop-change

  3. Allow file execution:

     • chmod u+x /var/svn/repos/repository_name/hooks/pre-revprop-change

  4. Change file owner, group and permissions so the svnserve can access:

     • find /var/svn/repos/repository_name -exec chown svn '{}' \;

     • find /var/svn/repos/repository_name -exec chgrp svn '{}' \;

     • find /var/svn/repos/repository_name -exec chmod ug+rwX '{}' \;

     • find /var/svn/repos/repository_name -exec chmod o= '{}' \;

  5. Initialize the repository for synchronization:

     • svnsync init svn://127.0.0.1/repository_name svn://source.machine.ip/repository_name \

     • --non-interactive \

     • --no-auth-cache \

     • --trust-server-cert \

     • --source-username user_for_sync_on_source_machine \

     • --source-password pass_for_sync_user \

     • --sync-username user_for_sync_on_destination \

     • --sync-password pass_for_sync_user \

     • --config-dir /var/svn

  6. Synchronize:

     • svnsync sync svn://127.0.0.1/repository_name \

     • --non-interactive \

     • --no-auth-cache \

     • --trust-server-cert \

     • --source-username user_for_sync_on_source_machine \

     • --source-password pass_for_sync_user \

     • --sync-username user_for_sync_on_destination \

     • --sync-password pass_for_sync_user \

     • --config-dir /var/svn

  7. Should be up and running...

See also examples below, and attached files.

Setting permissions:

#!/bin/bash

if [ "$1" = "" ]

then

echo "Usage: $0 repository_name"

else

yes | cp /var/svn/svnserve.conf /var/svn/repos/$1/conf

find /var/svn/repos/$1 -exec chown svn '{}' \;

find /var/svn/repos/$1 -exec chgrp svn '{}' \;

find /var/svn/repos/$1 -exec chmod ug+rwX '{}' \;

find /var/svn/repos/$1 -exec chmod o= '{}' \;

fi

Creating a repository:

#!/bin/bash

SVNDIR=/opt/CollabNet_Subversion/bin

if [ "$1" = "" ]

then

echo "Usage: $0 repository_name"

else

$SVNDIR/svnadmin create /var/svn/repos/$1

/var/svn/r.access.sh $1

fi

Initializing for synchronization:

#!/bin/bash

SVNDIR=/opt/CollabNet_Subversion/bin

if [ "$1" = "" ]

then

echo "Usage: $0 repository_name"

else

/var/svn/r.create.sh $1

echo "#!/bin/bash" > /var/svn/repos/$1/hooks/pre-revprop-change

chmod u+x /var/svn/repos/$1/hooks/pre-revprop-change

/var/svn/r.access.sh $1

$SVNDIR/svnsync init svn://127.0.0.1/$1 svn://source.machine.ip/$1 \

--non-interactive \

--no-auth-cache \

--trust-server-cert \

--source-username user_for_sync_on_source_machine \

--source-password pass_for_sync_user \

--sync-username user_for_sync_on_destination \

--sync-password pass_for_sync_user \

--config-dir /var/svn

fi

Synchronizing:

#!/bin/bash

SVNDIR=/opt/CollabNet_Subversion/bin

if [ "$1" = "" ]

then

echo "Usage: $0 repository_name"

else

$SVNDIR/svnsync sync svn://127.0.0.1/$1 \

--non-interactive \

--no-auth-cache \

--trust-server-cert \

--source-username user_for_sync_on_source_machine \

--source-password pass_for_sync_user \

--sync-username user_for_sync_on_destination \

--sync-password pass_for_sync_user \

--config-dir /var/svn

fi

Checking out:

#!/bin/bash

SVNDIR=/opt/CollabNet_Subversion/bin

if [ "$1" = "" ]

then

echo "Usage: $0 repository_name"

else

$SVNDIR/svn checkout svn://127.0.0.1/$1 /company/projects/folder/$1 \

--username user_for_sync \

--password pass_for_sync_user \

--no-auth-cache \

--non-interactive \

--trust-server-cert

fi

See attached files below.

Remember, contents depend on your configuration.