From 71fb89e02889ec64db3659ddf13740ac2fe22407 Mon Sep 17 00:00:00 2001 From: Ben Busby Date: Wed, 10 Nov 2021 11:50:19 -0700 Subject: Move instance selection logic out of router 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. --- lib/farside.ex | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) (limited to 'lib/farside.ex') diff --git a/lib/farside.ex b/lib/farside.ex index f87706a..0595e33 100644 --- a/lib/farside.ex +++ b/lib/farside.ex @@ -1,5 +1,6 @@ defmodule Farside do @service_prefix Application.fetch_env!(:farside, :service_prefix) + @fallback_str Application.fetch_env!(:farside, :fallback_str) def get_services_map do {:ok, service_list} = Redix.command(:redix, ["KEYS", "#{@service_prefix}*"]) @@ -24,6 +25,36 @@ defmodule Farside do end) end + def pick_instance(service) do + {:ok, instances} = + Redix.command( + :redix, + [ + "LRANGE", + "#{@service_prefix}#{service}", + "0", + "-1" + ] + ) + + # Either pick a random available instance, + # or fall back to the default one + instance = + if Enum.count(instances) > 0 do + Enum.random(instances) + else + {:ok, result} = + Redix.command( + :redix, + ["GET", "#{service}#{@fallback_str}"] + ) + + result + end + + instance + end + def get_last_updated do {:ok, last_updated} = Redix.command( -- cgit v1.2.3