How can I customize Kong access log, for example not logging 2xx and 3xx requests?
How to customize Kong access logs
Uses:
Kong Gateway
TL;DR
How do I customize Kong’s access logs to skip 2xx and 3xx requests?
Write a custom Nginx template based on Kong’s default one, adding an nginx map block (map $status $loggable { ~^[23] 0; default 1; }) and setting proxy_access_log to use if=$loggable. Start Kong with --nginx-conf pointing at the custom template, escaping the $ as $$ or \$ when it’s set via an environment variable, so only non-2xx/3xx requests are logged.
Steps
To customize Kong access logs, basically you need to write a custom Nginx template and use the map module to remove the 2xx and 3xx requests. For the template, take as model the file /usr/local/kong/kong.conf and add the map:
pid pids/nginx.pid;
error_log /dev/stderr notice;
# injected nginx_main_* directives
daemon off;
worker_processes auto;
worker_rlimit_nofile 16384;
env KONG_LICENSE_DATA;
env KONG_LICENSE_PATH;
include 'nginx-inject.conf';
events {
# injected nginx_events_* directives
multi_accept on;
worker_connections 16384;
}
http {
map $status $loggable {
~^[23] 0;
default 1;
}
include 'nginx-kong.conf';
}This file needs to be located in the /usr/local/kong/ directory as references /usr/local/kong/nginx-kong.conf
Then you need to start Kong to use this config:
kong start --nginx-conf /usr/local/kong/custom-nginx.confAnd configure proxy_access_log as below:
proxy_access_log = /dev/stdout combined if=$loggableIf using environment variables you may need to escape the $ character:
KONG_PROXY_ACCESS_LOG: "/dev/stdout combined if=$$loggable"If running docker from the terminal directly, you also need to escape the $ character as \$:
docker run --network bridge -d --name kong-dbless \
-v $(pwd)/custom_nginx.conf:/usr/local/kong/custom-nginx.conf \
-v "$(pwd)/declarative:/kong/declarative/" \
-v "$(pwd)/tmp_volume:/tmp" \
-v "$(pwd)/prefix_volume:/var/run/kong" \
-e "KONG_PREFIX=/var/run/kong" \
-e "KONG_DATABASE=off" \
-e "KONG_DECLARATIVE_CONFIG=/kong/declarative/kong3.yaml" \
-e "KONG_ADMIN_ACCESS_LOG=/dev/stdout" \
-e "KONG_PROXY_ERROR_LOG=/dev/stderr" \
-e "KONG_ADMIN_ERROR_LOG=/dev/stderr" \
-e "KONG_ADMIN_LISTEN=0.0.0.0:8001" \
-e "KONG_PROXY_LISTEN=0.0.0.0:8000" \
-e "KONG_PROXY_ACCESS_LOG=/dev/stdout combined if=\$loggable" \
-e "KONG_LICENSE_DATA=$KONG_LICENSE_DATA" \
-p 8000:8000 \
-p 8443:8443 \
-p 8001:8001 \
-p 8444:8444 \
-p 8002:8002 \
-p 8445:8445 \
-p 8003:8003 \
-p 8004:8004 \
kong/kong-gateway \
kong start --nginx-conf /usr/local/kong/custom-nginx.confAdditional information
- Kong docs: How to Customize Gateway Logs
- Nginx docs: Configuring Logging - Enabling Conditional Logging