Tutorial: Making Changes on the Permanent Web
These Lessons are tested with go-ipfs version 0.5.0. Please update this file on github to reflect any other versions that have been tested.
These Lessons will teach you how to
- Update Files on IPFS using IPNS (InterPlanetary Name System)
- Explain how version histories of files appear on IPFS
- Explain why IPFS is called the Permanent Web
- Track and Publish an entire website as it changes over time using IPFS and IPNS
- The Permanent Web
- Using hashes to uniquely identify versions of content
Normally, updating content means replacing a file - for instance, if I update a blog post, then people will see the new edited file, and not the old one. However, with IPFS, both versions of the file will be accessible in the network. It's not a matter of replacing: you add the new one, too. This raises the question: how do we actually update our links, so that people will see the new version of a file? They can't go to the file's location, because IPFS locates files by looking for their hashes (that's what content-addressed means). So, you need to have a way of pointing people to the new hash easily.
The trick is to add new the content, and then update a pointer to that content. So, there needs to be a way of having a mutable pointer.
This is where IPNS comes in, the InterPlanetary Name System. IPNS is a simple service that uses your peer ID to point to a particular hash. This hash can change, but your peer ID doesn't. That means that you can point to content in IPFS that may also change, and people can still access it without needing to know the new hash before hand.