This is needed to avoid triggering a CORS preflight (which occurs when using an X-API-KEY header). The core isn't currently capable of responding to a preflight and the UI therefore blocks the entire request. See: https://stackoverflow.com/a/43881141
This allows users to set only their data path, and for the temp folder to automatically follow it. The temp folder can be moved to a custom location by setting the "tempDataPath" setting.
An API key is now _required_ for sensitive API calls that would previously have allowed local loopback authentication.
Previously, a request would have been considered authenticated if it originated from the same machine, however this creates a security issue when running third party code (particularly javascript) via the data network.
The solution is to now require an API key to authenticate sensitive API calls no matter where the request originates from.
It works as follows:
- When the core is first installed, it has no API key generated and will block sensitive calls until generated.
- A new POST /admin/apikey/generate API endpoint has been added, which can be used the generate an API key for a newly installed node. The UI will ultimately call this automatically.
- This API returns the generated key so that it can be stored by the requesting app (most likely the UI).
- From then on, the generate API requires authentication via the existing API key in order to regenerate a key. It can be used as a security measure if the existing key is compromised.
- The API key must be passed to all sensitive API endpoints from then on, even when calling it from the same local machine.
- If the core already has a legacy API key specified via the 'apiKey' setting, this will be automatically copied to the new format so that a new one doesn't need to be generated.
- The API key itself is stored in a flat file in the qortal directory (the path can be customized using the `apiKeyPath` setting). Deleting this file and restarting the core will allow a new one to be regenerated.
The process of serving resources to a browser will likely be needed for more than just websites (e.g. it will be needed for apps too) so it makes sense to abstract it to its own class.
This should help keep the peer lookup table size down, as there is no need to locate files for transactions that existed before the most recent PUT transaction.
Built resources are deleted when either:
- The resource reaches the expiry interval specified in the builtDataExpiryInterval setting (default 30 days)
- The resource is published by a name that is in the local blacklist
Resources only exist in the reader cache once they have been viewed, to remove the loading time on subsequent views. But some may prefer to reduce this expiry time (at the expense of longer load times and more CPU), as data is held unencrypted in the cache.
We still allow it to be fetched even if it's outside of the storage policy, as the cleanup manager will delete the files very soon after, and they won't be allowed to be served to other peers due to other checks already in place.
This allows other peers to find out where they can obtain these files if we were to stop hosting them later. Or even if we continue hosting copies, it still informs the network on other locations, for better decentralization.
We don't want the network being spammed when a file isn't available by any reachable peers. This feature ensures retries are spaced out over longer timeframes. Basic logic:
- Wait 5 minutes in between failed attempts
- After 5 failed attempts (i.e. 25 mins) only try once per day from then on
- A core restart resets the counters
The stats gathered here can also be used to inform the core of when it should attempt a direct connection with a peer to obtain the data. That part isn't implemented yet.
This allows for custom list creation without the need for creating API endpoints to go along with it. This should save time now that we are using lists more.
- "APP" will allow for user-created apps and the Qortal app store
- "METADATA" will be used to supply info about apps/websites/resources, such as title, description, tags, etc
When using POST /arbitrary/{service}/{name}... it will now automatically decide which method to use (PUT/PATCH) based on a few factors:
- If there are already 10 or more layers, use PUT to reset back to a single layer
- If the next layer's patch is more than 20% of the total resource file size, use PUT
- If the next layer modifies more than 50% of the total file count, use PUT
- Otherwise, use PATCH
The PUT method causes a new base layer to be created and all previous update history for that resource becomes obsolete. The PATCH method adds a small delta layer on top of the existing layer(s).
The idea is to wipe the slate clean with a new base layer once the patches start to get demanding for the network to apply. Nodes which view the content will ultimately have build timeouts to prevent someone from deploying a resource with hundreds of complex layers for example, so this approach is there to maximize the chances of the resource being buildable.
The constants above (10 layers, 20% total size, 50% file count) will most likely need tweaking once we have some real world data.
We may choose to save on CPU by not compressing individual files, so this allows the network to support that. However it is still using compression by default, to reduce file sizes.
This process could potentially be simplified if we were to modify the structure of the actual zipped data (on the writer side), but this approach is more of a "catch-all" (on the reader side) to support multiple different zip structures, giving us more flexibility. We can still choose to modify the written zip structure if we choose to, which would then cause most of this new code to be skipped.
Note: the filename of a single file is not currently retained; it is renamed to "data" as part of the packaging process. Need to decide if this is okay before we go live.
Thumbnails will be used in order to show logos/screenshots in the list of websites or other resources. Playlists will allow for media apps to group videos/audio/images into collections, e.g. albums.
Until now we have been limited to one data resource per name/service combination. This meant that each name could only have a single website, git repo, image, video, etc, and adding another would overwrite the previous data. The identifier property now allows an optional string to be supplied with each resource, therefore allowing an unlimited amount of resources per name/service combination.
Some examples of what this will allow us to do:
- Create a video library app which holds multiple videos per name
- Same as above but for photos
- Store multiple images against each name, such as an avatar, website thumbnails, video thumbnails, etc. This will be necessary for many "system level" features.
- Attach multiple websites to each name. The default website (with blank/null identifier) would remain the entry point, but other websites could be hosted essentially as subdomains, and then linked from the default site. This also provides a means to go beyond the 500MB website size limit.
Not all of these features will exist initially, but having this identifier included in the protocol layer allows them to be added at any time.
