About

Mwbuild is the tool used by Metaweb Technologies to handle configuration, build, deployment and runtime management of production services behind Freebase.com. Mwbuild takes a novel lightweight approach to deployment and configuration such that a single tool is used by both developers and operations staff.

Implemented as a superset of the Subversion VCS, it facilitates source-based configuration and deployment of software components. A flexible INI-style configuration format with late-binding variable expansion allows for highly normalised specification of key/value pairs across a large number of machines and machine classes.

It has an advanced process monitor (nanny) which handles logging of standard output streams, reliable start and stop, optional auto-restart in the event of a crash (with backoff), timed operations (a la cron) and process health checks. The nanny also presents a HTTP interface to various detailed statistics and logs in humanly readable and JSON formats. Nanny additionally supports a UDP multicast discovery and query mechanism.

Getting it

At the moment, mwbuild is only available in source code form. You can grab it from Google Code's Mercurial repository with this command:

hg clone https://mwbuild.googlecode.com/hg/ mwbuild 

The only dependencies at this time are:

• apr-util
• GNU make

Assuming you have these installed, it should compile cleanly on:

• Gentoo Linux
• Fedora Linux
• Mac OS X
• OpenBSD
• FreeBSD

Documentation

The simplest possible configuration is 3 lines. Put a file named project.mw4 into the root directory of your project. Here is a sample for a project called Unworkable:

$ cat project.mw4 
[project:unworkable]
PROJECT_BUILD_CMD="make"
PROJECT_START_CMD="exec unworkable"

Assuming the mwbuild mw binary is in your path, you simply type mw build to build. Optionally you can use the -v (verbose) flag to get build output tee'd to console in addition to logfiles:

$ mw build -v
Synthesizing machine config from project.mw4
PROJECT_APPDIR="/home/az/niallo/projects/unworkable"
Executing: make
# some build output...

Now to start, you just use mw start:

$ mw start
Starting project 'unworkable'
nanny: unworkable http://localhost:36193/

And you can see the nanny process running:

$ ps axuww | grep nanny
niallo    5089  0.0  0.1  2180  2096 ??  Ss     4:59PM    0:00.01 mw: nanny: unworkable HTTP_PORT: 36193 (mw)

Have a look at the nanny's HTTP interface. It exposes lots of cool stuff.

To stop the process you simply run mw stop:

$ mw stop
Stopping project 'unworkable' (nanny PID: 5089)
Stopped project 'unworkable' (nanny PID: 5089)

More in-depth documentation can be found in the MwbuildHowto