Why does nginx remove a / in the URL?

Question

We use nginx as proxy for our play framework 1.2.7 server. Some of the routes in play framework use a <.*> wildcard, the one in question here looks like

GET     /media/{bucket}/{id}/inline/{<.*>config}    MediaCtl.getMediaInlineImgIx

The config can contain a http server and for some reason nginx strips away one of the / in http:// . For example:

13:07:59,299 INFO  [play] ~ Anonymous Guest ~ MediaCtl.getImgIx(): config {"w":100,"h":65,"origin":"http:/localhost:8080","fit":"max"}

when using nginx via localhost:8080. When calling localhost:9010 directly I get

13:19:25,648 INFO  [play] ~ Anonymous Guest ~ MediaCtl.getImgIx(): config {"w":100,"h":65,"origin":"http://localhost:9010","fit":"max"}

I see no messages in access.log or error.log with regards to the URL mangling that seems to occur. Any suggestions on how to fix this?

Answer 1

nginx merges slashes from URLs on default see: http://nginx.org/en/docs/http/ngx_http_core_module.html#merge_slashes

You must use: merge_slashes off;