Farside was previously only looking for links containing "youtube.com"
when performing the redirect for full URLs to youtube, which obviously
doesn't work for youtu.be shortened links. This updates the matching
logic to use a regex element for every key in the services map in order
to match against multiple possible domains for each parent service.
Fixes#40
Farside now supports redirecting based on a provided link to a "parent"
service, if such a parent service is supported.
For example, a link such as:
farside.link/https://www.youtube.com/watch?v=dQw4w9WgXcQ
will now redirect to any of the available YouTube related frontends.
This works by matching against a mapping of "parent" service domains
("youtube.com", "reddit.com", etc) to a list of their respective frontend
alternatives (["invidious", "piped"], ["libreddit", "teddit"], etc). A
random element is chosen from this list, and the remainder of Farside's
routing logic proceeds as if the user had chosen the service directly to
begin with.
Closes#37
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 process of selecting a random (working) instance for a specified
service has been moved out of the router and into lib/farside.ex. Moving
forward, the router itself should have very simple and easy to follow
logic for all paths.
This introduces a number of new changes:
- Services are now inserted into redis with a prefix prepended to the
key name. This allows for easier filtering to get only live instances.
- The home page now uses an eex template for displaying all live
instances for every service, determined by the last update
- A "last_updated" field was added
- farside.ex was added to contain all functionality related to querying
for instances (WIP)
- Other improvements
