feat: show status of the instance with a colored dot

src/invidious/helpers/backend_info.cr

@@ -1,16 +1,55 @@
 module BackendInfo
   extend self
   @@exvpp_url : String = ""
+  @@status : Int32 = 0
 
-  def get_videoplayback_proxy
+  def check_backends
+    check_videoplayback_proxy()
+    check_companion()
+  end
+
+  def check_companion
     begin
-      response = HTTP::Client.get "#{CONFIG.invidious_companion.sample.private_url}/info"
-      exvpp_url = JSON.parse(response.body)["external_videoplayback_proxy"].to_s
+      response = HTTP::Client.get "#{CONFIG.invidious_companion.sample.private_url}/healthz"
+      if response.status_code == 200
+        @@status = 1
+        check_videoplayback_proxy()
+      else
+        @@status = 0
+      end
+    rescue
+      @@status = 0
+    end
+  end
+
+  def check_videoplayback_proxy
+    begin
+      info = HTTP::Client.get "#{CONFIG.invidious_companion.sample.private_url}/info"
+      exvpp_url = JSON.parse(info.body)["external_videoplayback_proxy"]?.try &.to_s
+      exvpp_url = "" if exvpp_url.nil?
       @@exvpp_url = exvpp_url
+      if exvpp_url.empty?
+        @@status = 2
+        return
+      else
+        begin
+          exvpp_health = HTTP::Client.get "#{exvpp_url}/health"
+          if exvpp_health.status_code == 200
+            @@status = 2
+            return
+          end
+        rescue
+          @@status = 1
+        end
+      end
     rescue
     end
   end
 
+  def get_status
+    return @@status
+  end
+
   def get_exvpp
     return @@exvpp_url
   end