This introduces a way of throttling requests in a way that makes sense
for the purpose of the app. The app only supports redirecting to one
particular service when browsing, which would seldom be required more
than once per second for normal "human" browsing.
Without this, the service could easily be used to DOS multiple instances
at once. That being said, anyone concerned about someone DOS-ing
multiple instances at once should be aware that this would be trivial to
do with a simple bash script. This is simply a preventative measure to
hopefully deter people from trying to attack all public instances of
private frontends using farside.link.
Note that this throttling applies to all routes in the app, including
the homepage. This could be updated to exclude the homepage I guess,
but I'm not really sure what the use case would be for that.
Introduces a new db key "<service>-previous" to track which instance was
last selected for a particular service. This allows for filtering the
list of available instances to exclude the instance that was last
picked, to ensure a (slightly) more even distribution of traffic.
There's still the possiblity of the following scenario, however:
:service instances > 2
/:service request #1 -> instance #1
/:service request #2 -> instance #2
/:service request #3 -> instance #1
/:service request #4 -> instance #2
where there are many ignored instances for a particular service. One
possible solution would be to implement the "<service>-previous" value
to be a list, rather than a single value, and push to that list until
only one element is left in the original "instance" array after
filtering, and then delete the "<service>-previous" key.
The name of the project is being refactored from Privacy Revolver to
Farside. The reasoning behind this is:
1. A shorter name is easier to remember
2. It can stand for "FOSS alternative redirecting service" (which I know
doesn't encapsulate all letters from "farside", but it's close enough).
This commit also includes improvements to the update script for
determining how far along the script is.
Rather than use a full blown framework*, adding basic routing with
Plug.Router seems to make more sense, since I'm not planning on hosting
any content through this app. The app itself will just be endpoints for
all available services that redirect the user to an available instance
for the requested service.
Note that I might change my mind about this, but that's unlikely. At
most there would just be a home page with info about available
instances, but even then that seems kinda pointless. Trying to keep this
as absolutely simple as possible.
*like Phoenix
