From 0a9703f16453e4dad5e796527329cd1a340c5301 Mon Sep 17 00:00:00 2001
From: wiz <j@wiz.biz>
Date: Fri, 1 Nov 2024 21:14:57 +0900
Subject: [PATCH] ops: Cache all electrs endpoints for minimum of 1s

---
 production/nginx/location-api.conf | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/production/nginx/location-api.conf b/production/nginx/location-api.conf
index 70d6d7568..80f513147 100644
--- a/production/nginx/location-api.conf
+++ b/production/nginx/location-api.conf
@@ -55,10 +55,10 @@ location /api/block/ {
 	rewrite ^/api/(.*) /$1 break;
 	try_files /dev/null @esplora-api-cache-forever;
 }
-# other API responses cannot be cached
+# we cache for 1s to mitigate DoS attacks
 location /api/ {
 	rewrite ^/api/(.*) /$1 break;
-	try_files /dev/null @esplora-api-cache-disabled;
+	try_files /dev/null @esplora-api-cache-minimal;
 }
 
 ###########
@@ -171,6 +171,23 @@ location @esplora-api-cache-disabled {
 	expires -1;
 }
 
+location @esplora-api-cache-minimal {
+	proxy_pass $esploraMainnet;
+
+	proxy_set_header Host $host;
+	proxy_set_header X-Real-IP $remote_addr;
+	proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+	proxy_set_header X-Forwarded-Proto $scheme;
+
+	proxy_cache_background_update on;
+	proxy_cache_use_stale updating;
+	proxy_cache apihot;
+	proxy_cache_valid 200 1s;
+	proxy_redirect off;
+
+	expires 1s;
+}
+
 location @esplora-api-cache-forever {
 	proxy_pass $esploraMainnet;