External Proxies: Use list of external videoplayback proxies

src/invidious.cr

@@ -72,6 +72,7 @@ PUBSUB_URL  = URI.parse("https://pubsubhubbub.appspot.com")
 REDDIT_URL  = URI.parse("https://www.reddit.com")
 YT_URL      = URI.parse("https://www.youtube.com")
 HOST_URL    = make_host_url(Kemal.config)
+EXT_VIDEOP_LIST = gen_videoplayback_proxy_list()
 
 CHARS_SAFE         = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"
 TEST_IDS           = {"AgbeGFYluEA", "BaW_jenozKc", "a9LDPn-MO4I", "ddFvjfvPnqk", "iqKdEhx-dD4"}
@@ -188,7 +189,7 @@ Invidious::Jobs.register Invidious::Jobs::ClearExpiredItemsJob.new
 
 Invidious::Jobs.register Invidious::Jobs::InstanceListRefreshJob.new
 
-if CONFIG.external_videoplayback_proxy
+if !CONFIG.external_videoplayback_proxy.empty?
   Invidious::Jobs.register Invidious::Jobs::CheckExternalProxy.new
 end
 

src/invidious/config.cr

@@ -180,7 +180,9 @@ class Config
   # of the backend
   property backends_delimiter : String = "|"
 
-  property external_videoplayback_proxy : String?
+  # External videoplayback proxies list. They should include `https://`
+  # at the start of the URI
+  property external_videoplayback_proxy : Array(String) = [] of String
 
   # Materialious redirects
   property materialious_domain : String?

src/invidious/helpers/utils.cr

@@ -383,3 +383,17 @@ def parse_link_endpoint(endpoint : JSON::Any, text : String, video_id : String)
   end
   return text
 end
+
+# Generates a list of external videoplayback proxies for 
+# CSP
+def gen_videoplayback_proxy_list
+  if !CONFIG.external_videoplayback_proxy.empty?
+    external_videoplayback_proxy = ""
+    CONFIG.external_videoplayback_proxy.each do |proxy|
+      external_videoplayback_proxy += " #{proxy}"
+    end
+  else
+    external_videoplayback_proxy = ""
+  end
+  return external_videoplayback_proxy
+end

src/invidious/http_server/utils.cr

@@ -4,14 +4,20 @@ module Invidious::HttpServer
   module Utils
     extend self
 
-    @@proxy_alive : Bool = false
+    @@proxy_alive : String = ""
 
     def check_external_proxy
-      begin
-        response = HTTP::Client.get("#{CONFIG.external_videoplayback_proxy}")
-        @@proxy_alive = response.status_code == 200
-      rescue
-        @@proxy_alive = false
+      CONFIG.external_videoplayback_proxy.each do |proxy|
+        begin
+          response = HTTP::Client.get(proxy)
+          if response.status_code == 200
+            @@proxy_alive = proxy
+            LOGGER.debug("CheckExternalProxy: Proxy set to: '#{proxy}'")
+            break
+          end
+        rescue
+          LOGGER.debug("CheckExternalProxy: Proxy '#{proxy}' is not available")
+        end
       end
     end
 
@@ -25,8 +31,8 @@ module Invidious::HttpServer
       url.query_params = params
 
       if absolute
-        if @@proxy_alive
-          return "#{CONFIG.external_videoplayback_proxy}#{url.request_target}"
+        if !@@proxy_alive.empty?
+          return "#{@@proxy_alive}#{url.request_target}"
         else
           return "#{HOST_URL}#{url.request_target}"
         end

src/invidious/routes/before_all.cr

@@ -28,12 +28,6 @@ module Invidious::Routes::BeforeAll
       extra_media_csp = ""
     end
 
-    if CONFIG.external_videoplayback_proxy
-      external_videoplayback_proxy = " #{CONFIG.external_videoplayback_proxy}"
-    else
-      external_videoplayback_proxy = ""
-    end
-
     # Only allow the pages at /embed/* to be embedded
     if env.request.resource.starts_with?("/embed")
       frame_ancestors = "'self' file: http: https:"
@@ -49,7 +43,7 @@ module Invidious::Routes::BeforeAll
       "style-src 'self' 'unsafe-inline'",
       "img-src 'self' data:",
       "font-src 'self' data:",
-      "connect-src 'self'" + external_videoplayback_proxy,
+      "connect-src 'self'" + EXT_VIDEOP_LIST,
       "manifest-src 'self'",
       "media-src 'self' blob:" + extra_media_csp,
       "child-src 'self' blob:",