The production instance of this metrics server is going to run on Ubuntu Feisty, which comes installed with rrdtool 1.2, but the ruby bindings I want (need) to use bind to 1.3. So this is how to install rrdtool on Feisty.
(1) download the source:
curl http://oss.oetiker.ch/rrdtool/pub/rrdtool.tar.gz > rrdtool.tar.gz
then follow the instructions rrdbuild page : basically,
./configure
sudo make
sudo make install
However, in order to get configure to complete, I needed to install a couple of dependencies, pango and xml-2. I like configure, it’s very good about telling you what is missing and where to get it. And the rrdbuild page is also great at specifying exactly how to install the missing packages.
I figured I was up and running at that point. I built the ruby bindings from {src dir}/bindings/ruby, but when I tried to run the files I had been running on my Mac, I got:
/usr/local/lib/ruby/site_ruby/1.8/x86_64-linux/RRD.so: librrd.so.4: cannot open shared object file: No such file or directory - /usr/local/lib/ruby/site_ruby/1.8/x86_64-linux/RRD.so (LoadError)
NOT COOL.
How can a file that exists, /usr/local/lib/ruby/site_ruby/1.8/x86_64-linux/RRD.so, not be found? Was it a permissions thing? I tried building as sudo, same thing. Then I made sure that the file actually existed, just to check my head. Yes, it’s there. Yes, I’m getting the same error. Wait. Could it be the librrd.so ? I try a
ldconfig -v | grep rrd
and only get librrd.so.2. Hmmm. OK, desperate times…I edit /etc/ld.so.conf.d/local-installs.conf, and add
/usr/local/rrdtool-1.3.0/lib
to the path. That worked. The ops team is not going to be super thrilled about the amount of jackassery it took to get this up and running, which is why I’m documenting it here. Because they’ll make me maintain it. Just like I would if I were in their shoes 
