enable caching behavior

docker-compose.yaml

@@ -6,6 +6,8 @@ services:
       - "./generic_conf/basic_vts_location.conf:/usr/local/openresty/nginx/conf/basic_vts_location.conf"
       - "./generic_conf/basic_vts_setup.conf:/usr/local/openresty/nginx/conf/basic_vts_setup.conf"
       - "./generic_conf/lua_path_setup.conf:/usr/local/openresty/nginx/conf/lua_path_setup.conf"
+      - "./generic_conf/setup_cache.conf:/usr/local/openresty/nginx/conf/setup_cache.conf"
+      - "./generic_conf/define_cache.conf:/usr/local/openresty/nginx/conf/define_cache.conf"
       - "./src/:/lua/src/"
 
   backend:

generic_conf/backend_definition.conf

@@ -0,0 +1,21 @@
+env BACKEND_HOST; # allow list for os.getenv
+env BACKEND_PORT; # allow list for os.getenv
+
+upstream backend {
+  server 0.0.0.1;   # just an invalid address as a place holder
+
+    balancer_by_lua_block {
+      local balancer = require "ngx.balancer"
+      local host = os.getenv("BACKEND_HOST")
+      local port = number(os.getenv("BACKEND_PORT"))
+
+      local ok, err = balancer.set_current_peer(host, port)
+      if not ok then
+        ngx.log(ngx.ERR, "failed to set the current peer: ", err)
+        return ngx.exit(500)
+      end
+    }
+
+  keepalive 10;  # connection pool
+}
+

generic_conf/define_cache.conf

@@ -0,0 +1,8 @@
+proxy_cache zone_1;
+proxy_cache_key $cache_key;
+proxy_cache_lock on;
+proxy_http_version 1.1;
+proxy_set_header Connection "";
+proxy_buffering on;
+proxy_buffers 16 16k;
+add_header X-Cache-Status $upstream_cache_status;

generic_conf/setup_cache.conf

@@ -0,0 +1,6 @@
+proxy_cache_path /cache/ levels=2:2 keys_zone=zone_1:10m max_size=10m inactive=10m use_temp_path=off;
+proxy_cache_lock_timeout 1s;
+proxy_cache_use_stale error timeout updating;
+proxy_read_timeout 1s;
+proxy_send_timeout 1s;
+proxy_ignore_client_abort on;

nginx_edge.conf

@@ -9,6 +9,7 @@ http {
 
   include lua_path_setup.conf;
   include basic_vts_setup.conf;
+  include setup_cache.conf;
 
   upstream backend {
     server backend:8080;
@@ -19,8 +20,12 @@ http {
     listen 8080;
 
     location / {
+      set_by_lua_block $cache_key {
+        return ngx.var.uri
+      }
+
       proxy_pass http://backend;
-      add_header X-Cache-Status $upstream_cache_status;
+      include define_cache.conf;
       add_header X-Edge Server;
     }