Gate the system clock

[mcandre]

cloudlibc offers engineers a tremendous gatekeeper for I/O, writing applications just once in terms of a simple API, and flexibly reconfiguring applications for many different workflows for runtime. Let's extend the same gatekeeping to calls for the current date and time. This is not so much a security measure, as a safety measure:

Gating the system clock makes it much easier to test complex applications for different clock values, such as several years in the future when important SSL certificates expire, and when 2038 breaks legacy applications. While developers are advised to program in terms of an injectable clock, most applications are not written this way. By intercepting these calls, we offer utility for integration testing this part of the total application input space.

For many systems, there will come a day when the true date breaks the application, and a convenient way to frequently reset the date to a historical value, will be the only way to resurrect these applications.