Tim Robinson

Browse the NPackage source on GitHub

This weekend I've had a couple of productive sessions on NPackage and I'm pretty happy with how it's working out.

I've set up package files on Amazon S3 for the following libraries:

• log4net
• Mono Cecil
• NHibernate
• NUnit
• Rhino Mocks
• SharpZipLib

These six packages test a few different scenarios:

• NUnit and SharpZipLib are needed to build NPackage itself
• Rhino Mocks is a good test because the download URL doesn't resemble the name of the file that gets downloaded; I had to write code to parse the HTTP Content-Disposition header to make sense of it
• Cecil is an example of a library that's distributed with the rest of Mono, which is supplied as a large .tar.gz archive (the other libraries on the list above are all .zip files)
• NHibernate is an example of a library that has its own dependencies, i.e. log4net

Although NPackage is working nicely for its own development, I need to put in more work before the installation process is simple enough. Right now the command to install NPackage's own dependencies looks like this:

NPackage http://np.partario.com/nunit-2.5.5.10112/nunit.np \
         http://np.partario.com/sharpziplib-0.85.5/sharpziplib.np

I'd like to simplify it to this:

np install nunit sharpziplib

To do this I'll need to handle dependencies properly. I expect I'll need to drop the approach of putting package descriptions in their own files: the client will need to contain enough intelligence to put together a dependency graph and install the right versions of the right packages. It will be easier to do this if the client can download a central package database list and make its decisions based on the descriptions within there.

I envisage having local databases that can contain a few local packages and delegate the rest to the central list on the web. I'd also like the client to be self-contained enough to carry on working even if this central package server falls over: the client should cache the most recent version of the list and work from there.