Use quantum core for update scheduling

Rather than requiring a traditional crontab install, the app now
leverages quantum-core (link below) to schedule the instance update/sync
task every 5 minutes. Some updates as a result:

  - The new job is scheduled at runtime in server.ex.
  - The update.exs script was refactored to be compiled along with the
    rest of the app as instances.ex.
  - Scheduler and Server modules were added for creating and executing
    the new update task
  - All shell scripts were removed, as they are no longer needed

https://github.com/quantum-elixir/quantum-core

1 files changed, 0 insertions, 88 deletions

diff --git a/update.exs b/update.exs
deleted file mode 100644
index bc9ba0d..0000000
--- a/update.exs
+++ /dev/null
@@ -1,88 +0,0 @@
-defmodule Instances do
-  @fallback_suffix Application.fetch_env!(:farside, :fallback_suffix)
-  @update_file Application.fetch_env!(:farside, :update_file)
-  @services_json Application.fetch_env!(:farside, :services_json)
-  @service_prefix Application.fetch_env!(:farside, :service_prefix)
-
-  def init() do
-    File.rename(@update_file, "#{@update_file}-prev")
-    update()
-  end
-
-  def request(url) do
-    cond do
-      System.get_env("FARSIDE_TEST") ->
-        :good
-      true ->
-        case HTTPoison.get(url) do
-          {:ok, %HTTPoison.Response{status_code: 200}} ->
-            # TODO: Add validation of results, not just status code
-            :good
-          _ ->
-            :bad
-        end
-    end
-  end
-
-  def update do
-    {:ok, file} = File.read(@services_json)
-    {:ok, json} = Poison.decode(file, as: [%Service{}])
-
-    # Loop through all instances and check each for availability
-    for service <- json do
-      IO.puts "======== " <> service.type
-      result = Enum.filter(service.instances, fn(instance_url) ->
-        IO.puts "         " <> instance_url
-        request(instance_url <> service.test_url) == :good
-      end)
-
-      add_to_redis(service, result)
-      log_results(service.type, result)
-    end
-  end
-
-  def add_to_redis(service, instances) do
-    # Remove previous list of instances
-    Redix.command(:redix, [
-      "DEL",
-      "#{@service_prefix}#{service.type}"
-    ])
-
-    # Update with new list of available instances
-    Redix.command(:redix, [
-      "LPUSH",
-      "#{@service_prefix}#{service.type}"
-    ] ++ instances)
-
-    # Set fallback to one of the available instances,
-    # or the default instance if all are "down"
-    if Enum.count(instances) > 0 do
-      Redix.command(:redix, [
-        "SET",
-        "#{service.type}#{@fallback_suffix}",
-        Enum.random(instances)
-      ])
-    else
-      Redix.command(:redix, [
-        "SET",
-        "#{service.type}#{@fallback_suffix}",
-        service.fallback
-      ])
-    end
-  end
-
-  def log_results(service_name, results) do
-    {:ok, file} = File.open(@update_file, [:append, {:delayed_write, 100, 20}])
-    IO.write(file, "#{service_name}: #{inspect(results)}\n")
-    File.close(file)
-  end
-end
-
-Instances.init()
-
-# Add UTC time of last update
-Redix.command(:redix, [
-  "SET",
-  "last_updated",
-  Calendar.strftime(DateTime.utc_now(), "%c")
-])