test with cache stuff removed

docker/nginx/conf.d/include/location-skylink

@@ -1,5 +1,61 @@
 include /etc/nginx/conf.d/include/cors;
-# include /etc/nginx/conf.d/include/proxy-buffer;
+include /etc/nginx/conf.d/include/proxy-buffer;
+include /etc/nginx/conf.d/include/track-download;
 
+limit_conn downloads_by_ip 100; # ddos protection: max 100 downloads at a time
+
+# ensure that skylink that we pass around is base64 encoded (transform base32 encoded ones)
+# this is important because we want only one format in cache keys and logs
+set_by_lua_block $skylink { return require("skynet.skylink").base64(ngx.var.skylink) }
+
+# $skylink_v1 and $skylink_v2 variables default to the same value but in case the requested skylink was:
+# a) skylink v1 - it would not matter, no additional logic is executed
+# b) skylink v2 - in a lua block below we will resolve the skylink v2 into skylink v1 and update 
+#      $skylink_v1 variable so then the proxy request to skyd can be cached in nginx (proxy_cache_key 
+#      in proxy-cache-downloads includes $skylink_v1 as a part of the cache key)
+set $skylink_v1 $skylink;
+set $skylink_v2 $skylink;
+
+# variable for Skynet-Proof header that we need to inject 
+# into a response if the request was for skylink v2
+set $skynet_proof '';
+
+# default download rate to unlimited
+set $limit_rate 0;
+
+access_by_lua_block {
+    if require("skynet.account").accounts_enabled() then
+        -- check if portal is in authenticated only mode
+        if require("skynet.account").is_access_unauthorized() then
+            return require("skynet.account").exit_access_unauthorized()
+        end
+
+        -- check if portal is in subscription only mode
+        if require("skynet.account").is_access_forbidden() then
+            return require("skynet.account").exit_access_forbidden()
+        end
+
+        -- get account limits of currently authenticated user
+        local limits = require("skynet.account").get_account_limits()
+
+        -- apply download speed limit
+        ngx.var.limit_rate = limits.download
+    end
+}
+
+header_filter_by_lua_block {
+    ngx.header["Skynet-Portal-Api"] = ngx.var.scheme .. "://" .. ngx.var.skynet_portal_domain
+    ngx.header["Skynet-Server-Api"] = ngx.var.scheme .. "://" .. ngx.var.skynet_server_domain
+}
+
+limit_rate_after 512k;
+limit_rate $limit_rate;
+
+proxy_read_timeout 600;
 proxy_set_header User-Agent: Sia-Agent;
-proxy_pass http://sia:9980/skynet/skylink/$skylink$path$is_args$args;
+
+# in case the requested skylink was v2 and we already resolved it to skylink v1, we are going to pass resolved 
+# skylink v1 to skyd to save that extra skylink v2 lookup in skyd but in turn, in case skyd returns a redirect 
+# we need to rewrite the skylink v1 to skylink v2 in the location header with proxy_redirect
+proxy_redirect $skylink_v1 $skylink_v2;
+proxy_pass http://sia:9980/skynet/skylink/$skylink_v1$path$is_args$args;