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How to Create a Statically Linked Version of git Binaries

02.28.2011
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Creating a statically linked version of a unix software saves you in all the circumstances where you can’t install the software as root, when you don’t have development tools on the target machine, when you cannot find a prepackaged version for the specific server, when the libraries available on a server are conflicting with the ones required by your software, etc.

Examples:

  1. The unix server that hosts this blog, provides me a restricted shell to manage mysql and public web files with minimal access privileges. On this server I periodically update WordPress and other things, and I like to keep the changes under control and backed up with git. The problem is that on this server I haven’t git binaries, and I cannot install software and libraries required.
    Having the files of my WordPress installation under git version control saved me a lot of time in the past when somebody hacked into the server and changed the php files to do nasty stuff. I was able to easily check what was exactly changed since last legitimate update with “git status” command, and restore things as before.
  2. I own a little NAS (network attached storage) which runs a mini distribution of Linux which doesn’t have a prepackaged version of git to install, nor I cannot use any package management tool like apt rpm or yum etc.

So I thought that I can compile by myself the git binaries and have them deployed on the target machine. It is possible, but there is an important note: when you build a software on a unix server, the resulting binaries are referencing the libraries installed there, so you cannot easily port the binaries between servers since they have dependencies.
What you need is a “statically linked” version of the software, which fortunately it’s not so difficult to achieve. Binaries which are statically linked are usually bigger in size and will possibly require more memory to execute, but they won’t require the specific libraries to be present on the executing computer, since the libraries code is contained in the binaries themselves.

Here is how I built a static version of git on an ubuntu virtual machine, that can be ported to other unix servers:

# let's make sure we have all we need to proceed
$ sudo apt-get install libexpat1-dev asciidoc libz-dev gettext curl

# let's create the directory to host the built artifacts
$ sudo mkdir /opt/git-1.7.4.1-static

# we are ready to download and unpack latest version of git sources
$ curl http://kernel.org/pub/software/scm/git/git-1.7.4.1.tar.bz2 | tar xvj
$ cd git-1.7.4.1/

# then compile and install the files in the target directory we created
$ ./configure --prefix=/opt/git-1.7.4.1-static CFLAGS="${CFLAGS} -static" NO_OPENSSL=1 NO_CURL=1
$ sudo make install
$ sudo make install-doc

 

On the above commands, the thing to notice is the CFLAGS=”${CFLAGS} -static” which is used to specify that the libraries must be statically linked with the binaries.

The last thing to do is create a tarball of /opt/git-1.7.4.1-static folder and copy that on the target machine; adding the /opt/git-1.7.4.1-static/bin directory to the PATH variable and the /opt/git-1.7.4.1-static/share/man to the MANPATH variable.

If possible, it’s a good idea to keep the same installation path on target machine (/opt/git-1.7.4.1-static) since this path gets hardcoded in some git scripts during the build process. But it shouldn’t give too many problems, anyway.

 

From http://en.newinstance.it/2011/02/27/how-to-create-a-statically-linked-version-of-git-binaries/

Published at DZone with permission of Luigi Viggiano, author and DZone MVB.

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