Running a Subversion Server

1. Setup Users, Groups, and Permissions

You'll need to be user root for the initial portion of configuration. Create the svn user and group with the following commands:

groupadd -g 56 svn &&
useradd -c "SVN Owner" -d /home/svn -m -g svn -s /bin/false -u 56 svn

If you plan to have multiple repositories, you should have a group dedicated to each repository for ease of administration. Create the svntest group for the test repository and add the svn user to that group with the following commands:

groupadd -g 57 svntest &&
usermod -G svntest -a svn

Additionally you should set umask 002 while working with a repository so that all new files will be writable by owner and group. This is made mandatory by creating a wrapper script for svn and svnserve:

mv /usr/bin/svn /usr/bin/svn.orig &&
mv /usr/bin/svnserve /usr/bin/svnserve.orig &&
cat >> /usr/bin/svn << "EOF"
#!/bin/sh
umask 002
/usr/bin/svn.orig "$@"
EOF
cat >> /usr/bin/svnserve << "EOF"
#!/bin/sh
umask 002
/usr/bin/svnserve.orig "$@"
EOF
chmod 0755 /usr/bin/svn{,serve}

2. Create a Subversion repository.

There are several ways to set up a subversion repository. It is recommended to have a look at the SVN Book corresponding chapter. A basic repository can be set up with the instructions below.

Create a new Subversion repository with the following commands (as the root user):

install -v -m 0755 -d /srv/svn &&
install -v -m 0755 -o svn -g svn -d /srv/svn/repositories &&
svnadmin create /srv/svn/repositories/svntest

Now that the repository is created, it should be populated with something useful. You'll need to have a predefined directory layout set up exactly as you want your repository to look. For example, here is a sample BLFS layout setup with a root of svntest/. You'll need to setup a directory tree similar to the following:

svntest/            # The name of the repository
   trunk/           # Contains the existing source tree
      BOOK/
      bootscripts/
      edguide/
      patches/
      scripts/
   branches/        # Needed for additional branches
   tags/            # Needed for tagging release points

Once you've created your directory layout as shown above, you are ready to do the initial import:

svn import -m "Initial import." \
    </path/to/source/tree>      \
    file:///srv/svn/repositories/svntest

Now change owner and group information on the repository, and add an unprivileged user to the svn and svntest groups:

chown -R svn:svntest /srv/svn/repositories/svntest    &&
chmod -R g+w         /srv/svn/repositories/svntest    &&
chmod g+s            /srv/svn/repositories/svntest/db &&
usermod -G svn,svntest -a <username>

svntest is the group assigned to the svntest repository. As mentioned earlier, this eases administration of multiple repositories when using OpenSSH for authentication. Going forward, you'll need to add your unprivileged user, and any additional users that you wish to have write access to the repository, to the svn and svntest groups.

In addition, you'll notice that the new repository's db directory is set-groupID. If the reasoning is not immediately obvious, when using any external authentication method (such as ssh), the sticky bit is set so that all new files will be owned by the user, but group of svntest. Anyone in the svntest group can create files, but still give the entire group write access to those files. This avoids locking out other users from the repository.

Now, return to an unprivileged user account, and take a look at the new repository using svnlook:

svnlook tree /srv/svn/repositories/svntest/

3. Configure the Server

As mentioned previously, these instructions will configure the server to use only ssh for write access to the repository and to provide anonymous access using svnserve. There are several other ways to provide access to the repository. These additional configurations are best explained at http://svnbook.red-bean.com/.

Access configuration needs to be done for each repository. Create the svnserve.conf file for the svntest repository using the following commands:

cp /srv/svn/repositories/svntest/conf/svnserve.conf \
   /srv/svn/repositories/svntest/conf/svnserve.conf.default &&

cat > /srv/svn/repositories/svntest/conf/svnserve.conf << "EOF"
[general]
anon-access = read
auth-access = write
EOF

There is not a lot to the configuration file at all. You'll notice that only the general section is required. Take a look at the svnserve.conf.default file for information on using svnserve's built-in authentication method.

4. Starting the Server

To start the server at boot time, install the svnserve.service unit from the blfs-systemd-units-20210122 package:

make install-svnserve

Additionally, the instructions above require that svn server uses umask 002 so that all new files will be writable by owner and group. This can be achieved by creating a systemd unit override file by running the following command:

mkdir -p /etc/systemd/system/svnserve.service.d 
echo "UMask=0002" > /etc/systemd/system/svnserve.service.d/99-user.conf

Options which are passed to svnserve daemon can be changed in /etc/default/svnserve.