From 1bbb96230c6d3a157dc2e3eb731fff419537677a Mon Sep 17 00:00:00 2001
From: Goten Xiao <me@gotenxiao.co.uk>
Date: Sat, 23 Apr 2022 22:13:57 +0100
Subject: [PATCH] Use conditional slicing

---
 overlay/etc/nginx/conf.d/31_slice_maps.conf                   | 4 ++++
 .../etc/nginx/sites-available/cache.conf.d/root/20_cache.conf | 3 ++-
 .../nginx/sites-available/cache.conf.d/root/30_cache_key.conf | 2 +-
 3 files changed, 7 insertions(+), 2 deletions(-)
 create mode 100644 overlay/etc/nginx/conf.d/31_slice_maps.conf

diff --git a/overlay/etc/nginx/conf.d/31_slice_maps.conf b/overlay/etc/nginx/conf.d/31_slice_maps.conf
new file mode 100644
index 0000000..3025356
--- /dev/null
+++ b/overlay/etc/nginx/conf.d/31_slice_maps.conf
@@ -0,0 +1,4 @@
+map "${cacheidentifier}${http_range}" $slice_range_actual {
+    default $slice_range; # Use the calculated slice range by default
+    ~steam$ ""; # Disable slicing for Steam when the client request isn't a range, as not all CDN nodes accept range requests
+}
diff --git a/overlay/etc/nginx/sites-available/cache.conf.d/root/20_cache.conf b/overlay/etc/nginx/sites-available/cache.conf.d/root/20_cache.conf
index 4fb1ce4..e016760 100644
--- a/overlay/etc/nginx/sites-available/cache.conf.d/root/20_cache.conf
+++ b/overlay/etc/nginx/sites-available/cache.conf.d/root/20_cache.conf
@@ -4,7 +4,8 @@
 
     proxy_ignore_headers Expires Cache-Control;
     proxy_cache_valid 200 206 CACHE_MAX_AGE;
-    proxy_set_header  Range $slice_range;
+    # $slice_range_actual is set from the map in 31_slice_maps.conf
+    proxy_set_header  Range $slice_range_actual;
 
     # Only download one copy at a time and use a large timeout so
     # this really happens, otherwise we end up wasting bandwith
diff --git a/overlay/etc/nginx/sites-available/cache.conf.d/root/30_cache_key.conf b/overlay/etc/nginx/sites-available/cache.conf.d/root/30_cache_key.conf
index e2d5580..c406a4b 100644
--- a/overlay/etc/nginx/sites-available/cache.conf.d/root/30_cache_key.conf
+++ b/overlay/etc/nginx/sites-available/cache.conf.d/root/30_cache_key.conf
@@ -1 +1 @@
-    proxy_cache_key      $cacheidentifier$uri$slice_range;
+    proxy_cache_key      $cacheidentifier$uri$slice_range_actual;