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<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Supporting Multiple Repository Access Methods</title><link rel="stylesheet" href="styles.css" type="text/css" /><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /><link rel="start" href="index.html" title="Version Control with Subversion" /><link rel="up" href="svn.serverconfig.html" title="Chapter 6. Server Configuration" /><link rel="prev" href="svn.serverconfig.pathbasedauthz.html" title="Path-Based Authorization" /><link rel="next" href="svn.customization.html" title="Chapter 7. Customizing Your Subversion Experience" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Supporting Multiple Repository Access Methods</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="svn.serverconfig.pathbasedauthz.html">Prev</a> </td><th width="60%" align="center">Chapter 6. Server Configuration</th><td width="20%" align="right"> <a accesskey="n" href="svn.customization.html">Next</a></td></tr></table><hr /></div><div class="sect1" lang="en" xml:lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="svn.serverconfig.multimethod"></a>Supporting Multiple Repository Access Methods</h2></div></div></div><p>You've seen how a repository can be accessed in many
different ways. But is it possible—or safe—for your
repository to be accessed by multiple methods simultaneously?
The answer is yes, provided you use a bit of foresight.</p><p>At any given time, these processes may require read and
write access to your repository:</p><div class="itemizedlist"><ul type="disc"><li><p>regular system users using a Subversion client (as
themselves) to access the repository directly via
<code class="literal">file://</code> URLs;</p></li><li><p>regular system users connecting to SSH-spawned private
<span class="command"><strong>svnserve</strong></span> processes (running as
themselves) which access the repository;</p></li><li><p>an <span class="command"><strong>svnserve</strong></span> process—either a
daemon or one launched by
<span class="command"><strong>inetd</strong></span>—running as a particular fixed
user;</p></li><li><p>an Apache <span class="command"><strong>httpd</strong></span> process, running as a
particular fixed user.</p></li></ul></div><p>The most common problem administrators run into is repository
ownership and permissions. Does every process (or user) in the
previous list have the rights to read and write the Berkeley DB
files? Assuming you have a Unix-like operating system, a
straightforward approach might be to place every potential
repository user into a new <code class="literal">svn</code> group, and
make the repository wholly owned by that group. But even that's
not enough, because a process may write to the database files
using an unfriendly umask—one that prevents access by
other users.</p><p>So the next step beyond setting up a common group for
repository users is to force every repository-accessing process
to use a sane umask. For users accessing the repository
directly, you can make the <span class="command"><strong>svn</strong></span> program into a
wrapper script that first sets <span class="command"><strong>umask 002</strong></span> and
then runs the real <span class="command"><strong>svn</strong></span> client program. You
can write a similar wrapper script for the
<span class="command"><strong>svnserve</strong></span> program, and add a <span class="command"><strong>umask
002</strong></span> command to Apache's own startup script,
<code class="filename">apachectl</code>. For example:</p><pre class="screen">
$ cat /usr/bin/svn
#!/bin/sh
umask 002
/usr/bin/svn-real "$@"
</pre><p>Another common problem is often encountered on Unix-like
systems. As a repository is used, Berkeley DB occasionally
creates new log files to journal its actions. Even if the
repository is wholly owned by the <span class="command"><strong>svn</strong></span> group,
these newly created files won't necessarily be owned by that
same group, which then creates more permissions problems for
your users. A good workaround is to set the group SUID bit on
the repository's <code class="filename">db</code> directory. This causes
all newly-created log files to have the same group owner as the
parent directory.</p><p>Once you've jumped through these hoops, your repository
should be accessible by all the necessary processes. It may
seem a bit messy and complicated, but the problems of having
multiple users sharing write-access to common files are classic
ones that are not often elegantly solved.</p><p>Fortunately, most repository administrators will never
<span class="emphasis"><em>need</em></span> to have such a complex configuration.
Users who wish to access repositories that live on the same
machine are not limited to using <code class="literal">file://</code>
access URLs—they can typically contact the Apache HTTP
server or <span class="command"><strong>svnserve</strong></span> using
<code class="literal">localhost</code> for the server name in their
<code class="literal">http://</code> or <code class="literal">svn://</code> URLs.
And to maintain multiple server processes for your Subversion
repositories is likely to be more of a headache than necessary.
We recommend you choose the server that best meets your needs
and stick with it!</p><div class="sidebar"><p class="title"><b>The svn+ssh:// server checklist</b></p><p>It can be quite tricky to get a bunch of users with
existing SSH accounts to share a repository without
permissions problems. If you're confused about all the things
that you (as an administrator) need to do on a Unix-like
system, here's a quick checklist that resummarizes some of
things discussed in this section:</p><div class="itemizedlist"><ul type="disc"><li><p>All of your SSH users need to be able to read and
write to the repository, so: put all the SSH users into a
single group. </p></li><li><p>
Make the repository wholly owned by that group.
</p></li><li><p>Set the group permissions to read/write.</p></li><li><p>Your users need to use a sane umask when accessing the
repository, so: make sure that <span class="command"><strong>svnserve</strong></span>
(<code class="filename">/usr/bin/svnserve</code>, or wherever
it lives in <code class="literal">$PATH</code>) is actually a
wrapper script which sets <span class="command"><strong>umask 002</strong></span> and
executes the real <span class="command"><strong>svnserve</strong></span>
binary. </p></li><li><p>Take similar measures when using
<span class="command"><strong>svnlook</strong></span> and
<span class="command"><strong>svnadmin</strong></span>. Either run them with a sane
umask, or wrap them as described above.</p></li></ul></div></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="svn.serverconfig.pathbasedauthz.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="svn.serverconfig.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="svn.customization.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Path-Based Authorization </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 7. Customizing Your Subversion Experience</td></tr></table></div></body></html>
