feat: support configuring the buffer size of the access log (#10225)

Author: qihaiyan

apisix/cli/ngx_tpl.lua

@@ -365,8 +365,12 @@ http {
     log_format main escape={* http.access_log_format_escape *} '{* http.access_log_format *}';
     uninitialized_variable_warn off;
 
+    {% if http.access_log_buffer then %}
+    access_log {* http.access_log *} main buffer={* http.access_log_buffer *} flush=3;
+    {% else %}
     access_log {* http.access_log *} main buffer=16384 flush=3;
     {% end %}
+    {% end %}
     open_file_cache  max=1000 inactive=60;
     client_max_body_size {* http.client_max_body_size *};
     keepalive_timeout {* http.keepalive_timeout *};

conf/config-default.yaml

@@ -213,6 +213,7 @@ nginx_config:                     # Config for render the template to generate n
   http:
     enable_access_log: true             # Enable HTTP proxy access logging.
     access_log: logs/access.log         # Location of the access log.
+    access_log_buffer: 16384            # buffer size of access log.
     access_log_format: "$remote_addr - $remote_user [$time_local] $http_host \"$request\" $status $body_bytes_sent $request_time \"$http_referer\" \"$http_user_agent\" $upstream_addr $upstream_status $upstream_response_time \"$upstream_scheme://$upstream_host$upstream_uri\""
     # Customize log format: http://nginx.org/en/docs/varindex.html
     access_log_format_escape: default   # Escape default or json characters in variables.