support v2 caching

docker/nginx/conf.d/client.conf

@@ -409,6 +409,13 @@ server {
 		proxy_pass http://siad;
 	}
 
+	location /skynet/resolve {
+		include /etc/nginx/conf.d/include/cors;
+
+		proxy_set_header User-Agent: Sia-Agent;
+		proxy_pass http://siad;
+	}
+
 	location ~ "^/(([a-zA-Z0-9-_]{46}|[a-z0-9]{55})(/.*)?)$" {
 		include /etc/nginx/conf.d/include/cors;
 		include /etc/nginx/conf.d/include/proxy-buffer;
@@ -427,13 +434,24 @@ server {
 		set $skylink $2;
 		set $path $3;
 
+		# v2 support
+		set $skylink_v1 $skylink;
+
 		access_by_lua_block {
 			-- disable cache if this is skylink v2
 			local isBase32v2 = string.len(ngx.var.skylink) == 55 and string.sub(ngx.var.skylink, 0, 2) == "04"
 			local isBase64v2 = string.len(ngx.var.skylink) == 46 and string.sub(ngx.var.skylink, 0, 2) == "AQ"
 			
 			if isBase32v2 or isBase64v2 then
-				ngx.var.nocache = 1 # nginx expects 0/1 for boolean
+				local res = ngx.location.capture("/skynet/resolve/" .. ngx.var.skylink)
+				if res.status == ngx.HTTP_OK then
+					local json = require('cjson')
+					local resolve = json.decode(res.body)
+					ngx.var.skylink_v1 = resolve.skylink
+				else
+					ngx.say(res.body)
+					ngx.exit(res.status)
+				end
 			end
 
 			-- this block runs only when accounts are enabled
@@ -447,6 +465,16 @@ server {
 			end
 		}
 
+		# in case siad returns location header and we have skylink v2, we need to replace the skylink v1 with v2
+		header_filter_by_lua_block {
+			if ngx.var.skylink != ngx.var.skylink_v1 then
+				if ngx.header.location then
+					ngx.header.location = ngx.header.location:gsub("^" .. ngx.var.skylink_v1, ngx.var.skylink)
+				end
+				ngx.header["Skynet-Skylink"] = ngx.var.skylink
+			end
+		}
+
 		# register the download in accounts service (cookies should contain jwt)
 		log_by_lua_block {
 			-- this block runs only when accounts are enabled