FSVS: Updated install on CentOS 5.5

(Also see my older post on this: FSVS - Install on CentOS 5 or FSVS - Install on CentOS 5.4. Or the original post where I explained the power of FSVS for sysadmins.)

Once again, I'm starting with the assumption that this is a pretty bare-bones CentOS 5.5 server install, with only the "server" package group (or no package groups at all) being selected during the initial install.  The basic steps remain the same for situations where you merely want to use FSVS and SVN to keep track of changes to your system:

1. Setup the RPMForge repository
2. Install the packages needed for FSVS
3. Download and compile FSVS
4. Configure ignore patterns
5. Do the base check-ins

For the most part, I try to do this process as early in the lifespan of the server as possible.  But there's always a few minor things that get done before I get this far (creating an initial user, doing a "yum update" to patch the system up, etc).  Even a mature server can benefit from adding FSVS, but you'll find it much more useful the longer that you use it as it gives you a quick index to "what changed and why did you change it".

Setting up RPMForge

In order to get the latest Subversion packages for your system, you'll have to add RPMForge as a source repository. The CentOS base repository only has Subversion 1.4.2 and the latest is currently 1.6.12. I recommend doing this in conjunction with the yum-priorities package.

# yum install yum-priorities

After installing the yum-priorities package, you should edit the CentOS-Base.repo file found under /etc/yum.repos.d/. For the base repositories, I recommend setting them to priority values of 1 through 3  For example, in the "[base]" section, you would add (2) lines to the end of that section:

[base]
...
priority=1
exclude=subversion-*

The "priority=" tells yum-priorities that if it finds a package in multiple repositories, that [base] should take precedence.  The "exclude=" line keeps us from pulling Subversion from the [base] repository (and we'll instead pull it from RPMForge).

Now we can install the RPMForge repository (see Using RPMForge).  You'll need to look at the release folder in order to get the RPM name.

# cd /root/

# mkdir software

# cd software
# wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.1-1.el5.rf.x86_64.rpm
# rpm -Uhv rpmforge-release-0.5.1-1.el5.rf.x86_64.rpm
# cd /etc/yum.repos.d/

Now you should edit the rpmforge.repo file and insert a priority= line. I recommend a value of 10 or 25. In addition, I suggest also telling the yum package manager to only pull in specific packages from RPMForge (or any 3rd party repository).  This is a bit of overkill, but yum-priorities is a bit of overkill in itself and I've run into issues in the past where priorities weren't enough and I wish I had gone with using "includepkgs" instead.  (Note that while "exclude" is used to exclude packages, the opposite term is "includepkgs" and not "include".)  This will make the end of your rpmforge.repo file look like:

[rpmforge]

...
priority=10
includepkgs=subversion-*

You can verify that you'll pull in the latest Subversion package by the following command:

# yum info subversion
Available Packages
Name       : subversion
Arch       : x86_64
Version    : 1.6.12
Release    : 0.1.el5.rf
Size       : 6.8 M
Repo       : rpmforge
Summary    : Modern Version Control System designed to replace CVS
URL        : http://subversion.tigris.org/
License    : BSD

Install the packages needed for FSVS

# yum install subversion subversion-devel ctags apr apr-devel gcc gdbm gdbm-devel pcre pcre-devel apr-util-devel

Download and compile FSVS

As always, you shouldn't compile code as the root user.

# su username
$ mkdir -p ~/software/fsvs
$ cd ~/software/fsvs
$ wget http://download.fsvs-software.org/fsvs-1.2.2.tar.bz2
$ tar xjf fsvs-1.2.2.tar.bz2
$ cd fsvs-1.2.2
$ ./configure
$ make
$ exit
# cp /home/username/fsvs/fsvs-1.2.2/src/fsvs /usr/local/bin/
# chmod 755 /usr/local/bin/fsvs

Creating the repository on the SVN server

This is how we setup users on our SVN server. Machine accounts are prefixed as "sys-" in front of the machine name. The SVN repository name matches the name of the machine. In general, only the machine account should have write access to the repository, although you may wish to add other users to the group so that they can gain read-only access.

# useradd -m sys-www-test
# passwd sys-www-test
# svnadmin create /var/svn/sys-www-test
# chmod -R 750 sys-www-test
# chmod -R g+s sys-www-test/db
# chown -R sys-www-test:sys-www-test sys-www-test

Back on the source machine (our test machine), we'll need to create an SSH key that can be used on our SVN server. You may wish to use a slightly larger RSA key (3200 bits or 4096 bits) if you're working on an extra sensitive server. But a key size of 2048 bits should be secure for another decade for this purpose.

# cd /root/
# mkdir .ssh
# chmod .ssh 700
# cd .ssh
# /usr/bin/ssh-keygen -N '' -C 'svn key for root@hostname' -t rsa -b 2048 -f root@hostname
# chmod 600 *
# cat root@hostname.pub

Copy this key into the clipboard or send it to the SVN server or the SVN server administrator. Then we'll need to create a ~/.ssh/config file to tell the user what account name, port and key file to use when talking to the SVN server.

# vi /root/.ssh/config
Host svn.tgharold.com
Port 22
User sys-www-test
IdentityFile /root/.ssh/root@hostname
# chmod 600 *

Back on the SVN server, you'll need to finish configuration of the user that will add files to the SVN repository.

# su username
$ cd ~/
$ mkdir .ssh
$ chmod 700 .ssh
$ cd .ssh
$ cat >> authorized_keys
(paste in the SSH key from the other server)
$ chmod 600 *

Now you'll want to prepend the following in front of the key line in the authorized_keys file.

command="/usr/bin/svnserve -t -r /var/svn",no-agent-forwarding,no-pty,no-port-forwarding,no-X11-forwarding

That ensures (mostly) that the key can only be used to run the svnserve command and that it can't be used to access a command shell on the SVN server. Test the configuration back on the original server by issuing the "svn info" command. Alternately, you can try to ssh to the SVN repository server. Errors will usually either be logged in /var/log/secure on the source server or in the same log file on the SVN repository server. Here's an example of a successful connection:

# ssh svn.tgharold.com
( success ( 2 2 ( ) ( edit-pipeline svndiff1 absent-entries commit-revprops depth log-revprops partial-replay ) ) )

This shows that they key is running the "svnserve" command automatically.

Connect the system to the SVN repository

The very first command that you'll need to issue for FSVS is the "urls" (or "initialize") command. This tells FSVS what repository will be used to store the files.

# cd /
# mkdir /var/spool/fsvs
# mkdir /etc/fsvs/
# fsvs urls svn+ssh://svn.tgharold.com/sys-www-test/

You may see the following error, which means you need to create the /var/spool/fsvs folder, then reissue the fsvs urls command.

stat() of waa-path "/var/spool/fsvs/" failed. Does your local WAA storage area exist?

The following error means that you forgot to create the /etc/fsvs/ folder.

Cannot write to the FSVS_CONF path "/etc/fsvs/".

Configure ignore patterns and doing the base check-in

When constructing ignore patterns, generally work on adding a few directories at a time to the SVN repository. Everyone has different directories that they won't want to version, so you'll need to tailor the following to match your configuration. However, I generally recommend starting with the following (this is the output from "fsvs ignore dump", which you can pipe into a file, edit, then pipe back into "fsvs ignore load"):

group:ignore,./backup/
group:ignore,./bin/
group:ignore,./dev/
group:ignore,./etc/fsvs/
group:ignore,./etc/gconf/
group:ignore,./etc/gdm/
group:ignore,./home/
group:ignore,./lib/
group:ignore,./lib64/
group:ignore,./lost+found
group:ignore,./media/
group:ignore,./mnt/
group:ignore,./proc/
group:ignore,./root/
group:ignore,./sbin/
group:ignore,./selinux/
group:ignore,./srv/
group:ignore,./sys/
group:ignore,./tmp/
group:ignore,./usr/bin/
group:ignore,./usr/include/
group:ignore,./usr/kerberos/
group:ignore,./usr/lib/
group:ignore,./usr/lib64
group:ignore,./usr/libexec/
group:ignore,./usr/sbin/
group:ignore,./usr/share/
group:ignore,./usr/src/
group:ignore,./usr/tmp/
group:ignore,./usr/X11R6/
group:ignore,./var/cache/
group:ignore,./var/gdm/
group:ignore,./var/lib/
group:ignore,./var/lock/
group:ignore,./var/log/
group:ignore,./var/mail/
group:ignore,./var/run/
group:ignore,./var/spool/
group:ignore,./var/tmp/

Then you'll either want to ignore (or encrypt) the SSH key files.

# cd /
# fsvs ignore group:ignore,./root/.ssh
# fsvs ignore group:ignore,./etc/ssh/shadow*
# fsvs ignore group:ignore,./etc/ssh/ssh_host_key
# fsvs ignore group:ignore,./etc/ssh/ssh_host_dsa_key
# fsvs ignore group:ignore,./etc/ssh/ssh_host_rsa_key

You can check what FSVS is going to version by using the "fsvs status pathname" command (such as "fsvs status /etc"). Once you are happy with the selection in a particular path, you can do the following command:

# fsvs ci -m "base check-in" /etc

Repeat this for the various top level trees until you have checked everything in. Then you should do one last check-in at the root level that catches anything you might have missed.