Mercurial and Mercurial-server : playing with DVCS (part 2)

In my previous post I moved my first steps with Mercurial DVCS, now I'll install a Mercurial server implementation and configure both my computers to access it using SSH protocol.

Mercurial-server

With DVCS you don't have to use a central server, repositories could be shared over LAN using shared folders, but this doesn't mean you can't have one. Various mercurial server side implementations exists, using different protocols. May be I'm too server-client minded but I didn't feel satisfied by just sharing repositories over a shared folder so I decided to install Mercurial-server.

Installing Mercurial-server is an easy task the command

sudo apt-get install mercurial-server

complete the installation process and the creation of the application user (hg). A bit more complex is configuring SSH for accessing the server, I mainly followed instructions from here and from Mercurial-server documentation.

Mercurial-server uses public-key authentication and SSH-Agent in order to grant access to its clients, so the first step has been to generate a keys couple for SSH. The ssh-keygen command does this interactively.

maxx@VeritonS661:~$ ssh-keygen -t dsa

Generating public/private dsa key pair.

Enter file in which to save the key (/home/maxx/.ssh/id_dsa):

Enter passphrase (empty for no passphrase):

Enter same passphrase again:

Your identification has been saved in /home/maxx/.ssh/id_dsa.

Your public key has been saved in /home/maxx/.ssh/id_dsa.pub.

I then copied the public key in mercurial-server keys configuration path and told mercurial-server to refresh its authentication files, using the following commands:

ssh-add -L > maxx.key

sudo mkdir /etc/mercurial-server/keys/root/maxx

sudo cp maxx.key /etc/mercurial-server/keys/root/maxx /veritons661

sudo -u hg /usr/share/mercurial-server/refresh-auth

the usual path for mercurial-server keys is (for root users)

/etc/mercurial-server/keys/root/<user-name>

but if the same user must be accessed from different machines a different path is used:

/etc/mercurial-server/keys/root/<user-name>/<machine-name>

since I was going to add the maxx user from the EEEPC too I had to use, of course, the second from. On the EEEPC side I generated SSH keys at the same manner then, after logging to the desktop computer (the server) with:

ssh -A veritons661

and I eventually registered EEEPC's maxx user like this

ssh-add -L > eeepc900.key

sudo cp eeepc900.key /etc/mercurial-server/keys/root/maxx/eeepc900

sudo -u hg /usr/share/mercurial-server/refresh-auth

Mercurial and Mercurial-server : playing with DVCS (part 1)

Version control systems (VCS) are an indispensable tool when programming and sharing code even for small groups. Even while programming alone, but on different computers, a version control system could easily prove useful for securely sharing code between desktop and laptop computer. I use daily SVN, as version control while at work. For my homely experiments, instead, I decided to install something different: Mercurial, a distributed version control system (DVCS). Distributed version control systems, most famous are Git and Mercurial, do not rely on a central server to keep the code repository, in DVCS every developing computer keeps its own copy of the repository. What interested me in DVCS was the capability to do version control also when off-line and also, of course, the chance to learn something new.

Installing Mercurial (command-line and plugged-in)

Installing Mercurial command-line version it's quite trivial:

sudo apt-get install mercurial

Both Eclipse and Netbeans offers their plug-ins to interface with Mercurial. Netbeans plug-in is already provided with version 7.3.1 I have installed on the EEEPC. On Eclipse, desktop-side, installing the MercurialEclipse plug-in has been as simple as selecting it from the Eclipse Marketplace and following installation wizard.