Make height or width optional

Allow either height or width to be optional in the URL. URLs like `/x300/` set the width to `-`and resize only on the height. URLs like `/300x/` set the height to `-` and resize only on width.

nginx.conf

@@ -39,15 +39,25 @@ http {
         proxy_cache_valid      200  1d;
         proxy_cache_use_stale  error timeout invalid_header updating http_500 http_502 http_503 http_504;
 
+        if ($uri ~ "^/([1-9][0-9]{0,2})x/") {
+            set $width $1;
+            set $height -;
+        }
+
+        if ($uri ~ "^/x([1-9][0-9]{0,2})/") {
+            set $width -;
+            set $height $1;
+        }
+
         if ($uri ~ "^/([1-9][0-9]{0,2})x([1-9][0-9]{0,2})/") {
             set $width $1;
             set $height $2;
         }
 
         # Proxy new panoptes-uploads-staging requests to Azure storage
         # e.g. https://panoptes-uploads-staging.zooniverse.org/workflow_attached_image/704a79c1-e728-4ab3-828d-e398fba69ec3.jpeg
-        location ~ "^/[1-9][0-9]{0,2}x[1-9][0-9]{0,2}/panoptes-uploads-staging.zooniverse.org/.+$" {
-            rewrite "^/[1-9][0-9]{0,2}x[1-9][0-9]{0,2}/panoptes-uploads-staging.zooniverse.org(/.*)$" $1 break;
+        location ~ "^/[0-9]{0,3}x[0-9]{0,3}/panoptes-uploads-staging.zooniverse.org/.+$" {
+            rewrite "^/[0-9]{0,3}x[0-9]{0,3}/panoptes-uploads-staging.zooniverse.org(/.*)$" $1 break;
             resolver 8.8.8.8;
             proxy_pass https://panoptesuploadsstaging.blob.core.windows.net/public$uri?$query_string;
             proxy_set_header       Host panoptesuploadsstaging.blob.core.windows.net;
@@ -57,8 +67,8 @@ http {
 
         # Proxy old panoptes-uploads staging requests to Azure storage
         # e.g. https://panoptes-uploads.zooniverse.org/staging/workflow_attached_image/362d0a60-84a1-41db-9ea9-a42789f492c8.jpeg
-        location ~ "^/[1-9][0-9]{0,2}x[1-9][0-9]{0,2}/panoptes-uploads.zooniverse.org/staging/.+$" {
-            rewrite "^/[1-9][0-9]{0,2}x[1-9][0-9]{0,2}/panoptes-uploads.zooniverse.org/staging(/.*)$" $1 break;
+        location ~ "^/[0-9]{0,3}x[0-9]{0,3}/panoptes-uploads.zooniverse.org/staging/.+$" {
+            rewrite "^/[0-9]{0,3}x[0-9]{0,3}/panoptes-uploads.zooniverse.org/staging(/.*)$" $1 break;
             resolver 8.8.8.8;
             proxy_pass https://panoptesuploadsstaging.blob.core.windows.net/public$uri?$query_string;
             proxy_set_header       Host panoptesuploadsstaging.blob.core.windows.net;
@@ -69,8 +79,8 @@ http {
         # Proxy panoptes-uploads production requests to Azure storage
         # e.g. https://panoptes-uploads.zooniverse.org/production/workflow_attached_image/c3303c4d-28b2-453c-882c-63a95a5c41bc.jpeg
         #      https://panoptes-uploads.zooniverse.org/workflow_attached_image/6769554f-9079-41c8-acfc-393737a4972f.jpeg
-        location ~ "^/[1-9][0-9]{0,2}x[1-9][0-9]{0,2}/panoptes-uploads.zooniverse.org/.+$" {
-            rewrite "^/[1-9][0-9]{0,2}x[1-9][0-9]{0,2}/panoptes-uploads.zooniverse.org(?:/production)?(/.*)$" $1 break;
+        location ~ "^/[0-9]{0,3}x[0-9]{0,3}/panoptes-uploads.zooniverse.org/.+$" {
+            rewrite "^/[0-9]{0,3}x[0-9]{0,3}/panoptes-uploads.zooniverse.org(?:/production)?(/.*)$" $1 break;
             resolver 8.8.8.8;
             proxy_pass https://panoptesuploads.blob.core.windows.net/public$uri?$query_string;
             proxy_set_header       Host panoptesuploads.blob.core.windows.net;
@@ -80,7 +90,7 @@ http {
 
         # proxy all other requests to the azure zoonversestatic storage account, $web container
         location / {
-            rewrite "^/([1-9][0-9]{0,2}x[1-9][0-9]{0,2})(/.*)$" $2 break;
+            rewrite "^/([0-9]{0,3}x[0-9]{0,3})(/.*)$" $2 break;
             resolver 8.8.8.8;
             proxy_http_version 1.1;
             proxy_pass https://zooniversestatic.z13.web.core.windows.net$uri?$query_string;