While git is a completely distributed revision control system, sometimes
the lack of a central canonical repository can be annoying. For example,
you might want to make your repository published publically, so other
people can fork your code, or you might want all your developers to push
into (or have code pulled into) a central "golden" tree, that you then
use for automated building and continuous integration. This entry should
explain how to get this all working on Ubuntu 9.04 (Jaunty).
Gitosis is a very useful git repository manager, which adds support like
ACLs in pre-commits and gitweb and git-daemon management. While it's
possible to set all these things up by hand, gitosis does everything for
you. It is nicely configured via git; to make configuration changes,
you push the config file changes into gitosis repository on the server.
Gitosis is available in Jaunty, but unfortunately there is a
bug
in the version in Jaunty, which means it doesn't work out of the box.
Fortunately there is a fixed version in
jaunty-proposed that
fixes the main problem. This does mean that you need to add the
following to your
sources.list:
deb http://gb.archive.ubuntu.com/ubuntu/ jaunty-proposed universe
Run
apt-get update && apt-get install gitosis. You should
install
0.2+20080825-2ubuntu0.1 or later. There is another
small bug in the current version too, as a result of git removing the
git-$command scripts out of
/usr/bin. Edit
/usr/share/python-support/gitosis/gitosis/templates/admin/hooks/post-update
and replace
git-update-server-info
with
git update-server-info
With these changes in place, we can now set up our gitosis
repository. On the server you are going to use to host your central
repositories, run:
sudo -H -u gitosis gitosis-init < id_rsa.pub
The
id_rsa.pub file is a public ssh key. As I mentioned,
gitosis is managed over git, so you need an initial user to clone and
then push changes back into the gitosis repo, so make sure this key
belongs to a keypair you have available to the remote user you're going
to configure gitosis.
Now, on your local computer, you can clone the gitosis-admin repo
using:
git clone gitosis@gitserver.example.com:gitosis-admin.git
If you look inside the
gitosis-admin directory, you should
find a file called
gitosis.conf and a directory called
keydir. The directory is where you can add ssh public keys for
your users. The file is the configuration file for gitosis.
[gitosis]
loglevel = INFO
[group gitosis-admin]
writable = gitosis-admin
members = david@david
[group developers]
members = david@david
writable = publicproject privateproject
[group contributors]
members = george@wilber
writable = publicproject
[repo publicproject]
daemon = yes
gitweb = yes
[repo privateproject]
daemon = no
gitweb = no
This sets up two repositories, called publicproject and
privateproject. It enables the public project to be available via the
git protocol and in gitweb if you have that installed. We also create
two groups, developers and contributors. David has access to both
projects, but George only has access to change the publicproject. David
can also modify the gitosis configuration. The users are the names of
ssh keys (the last part of the line in id_dsa.pub or id_rsa.pub).
Once you've changed this file, you can run
git add
gitosis.conf to add it to the commit,
git commit -m "update
gitosis configuration to commit it to your local repository, and
finally
git push to push your commits back up into the central
repository. Gitosis should now update the configuration on the server to
match the config file.
One last thing to do is to enable git-daemon, so people can
anonymously clone your projects. Create /etc/event.d/git-daemon with the
following contents:
start on startup
stop on shutdown
exec /usr/bin/git daemon \
--user=gitosis --group=gitosis \
--user-path=public-git \
--verbose \
--syslog \
--reuseaddr \
--base-path=/srv/gitosis/repositories/
respawn
You can now start this using
start git-daemon
So now, you need to start using your repository. You can either start
with an existing project or an empty directory. Start by running
git init and then
git add $file to add each of the
files you want in your project, and finally
git commit to
commit them to your local repository. The final task is to add a remote
repository and push your code into it.
git remote add origin gitosis@gitserver.example.com:privateproject.git
git push origin master:refs/heads/master
In future, you should be able to do
git push to push your
changes back into the central repository. You can also clone a project
using git or ssh, providing you have access, using the following
commands. The first is for read-write access over ssh and the second
uses the git protocol for read-only access. The git protocol uses TCP
port 9418, so make sure that's available externally, if you want the
world to be able to clone your repos.
git clone gitosis@gitserver.example.com:publicproject.git
git clone git://gitserver.example.com/publicproject.git
Setting up GitWeb is left as an exercise for the reader (and myself
because I am yet to attempt to set that up).
I have a bit of money invested in stocks and funds, passively
managed by my bank. I ve made a bit with risky speculations, and
I ve lost about the same amount with the markets dive of the last
18 months. Net benefit: zero cash, a bit of experience. Time to
move on
I am not an interesting customer, so I was all the more
surprised to get a call from an employee of the bank the other day.
He identified himself as Crisis Manager or something similarly
ridiculous, mentioned at least 20 times that he was a regular
employee and wouldn t receive provisions, and he also kept assuring
me that he s doing himself what he s suggesting to me: leveraging
the cost-average effect.
I turned him down, probably a bit too briskily. Let s
investigate why.
Banks are good at devising ingenious tricks to fool people; it s
their business after all. One of those tricks is the so-called
cost-average effect. It s awesome, they say, because it is the
first product that adapts to the ever-changing market: when prices
are up, it buys smaller numbers of shares, and in low times, it
stocks up on them by buying larger quantities, automatically.
Fancy, no? It isn t, because the entire idea is to get your
signature on a contract that obliges you to pay a fixed sum each
month, with which shares are then bought. Obviously, when prices
are up, numbers you get for your money are low, and vice versa.
Observe how well the banks manage to turn that basic rule into a
selling point. They are good at that. In fact, that s probably all
they re good at. Obviously , inflation is also factored in, so the
monthly fixed sum actually increases by a projected 5% each year,
which they call inflation protection .
While this strategy investing fixed-sum installments rather
than lump sums certainly has its benefits, and can level out the
risk of throwing a large sum of money at the market, it is commonly
considered a suboptimal strategy, especially when employed over
longer spans of time. For more information, I refer you to the
frequently cited article 
I didn't spot this when I wrote my last post,
but it seems there's a security alert for FF3
already -