Nginx Request Exporter for Prometheus

This is a Prometheus exporter for Nginx requests.

In contrast to existing exporters nginx-request-exporter does not scrape the stub status module for server status but records statistics for HTTP requests.

By default nginx-request-exporter listens on port 9147 for HTTP requests.

Installation

Using go get

go get github.com/volodymyr-polishchuk/nginx-request-exporter

Docker

Build image:

docker build -t nginx-request-exporter .

Run:

docker run --rm -p 9147:9147 -p 9514:9514 nginx-request-exporter

Docker Compose Example

docker-compose.yml

Configuration

nginx-request-exporter consumes access log records using the syslog protocol. Nginx needs to be configured to log to nginx-request-exporter's syslog port. To enable syslog logging add a access_log statement to your Nginx configuration:

access_log syslog:server=127.0.0.1:9514 prometheus;

Log format

nginx-request-exporter uses a custom log format that needs to be defined in the http context.

The format has to only include key/value pairs:

• A key/value pair delimited by a colon denotes a metric name&value
• A key/value pair delimited by an equal sign denotes a label name&value that is added to all metrics.

Example:

log_format prometheus 'time:$request_time status=$status host="$host" method="$request_method" upstream="$upstream_addr"';

Key hostname is mandatory.

Multiple metrics can be recorded and all variables available in Nginx can be used. Currently, nginx-request-exporter has to be restarted when the log format is changed.

Environment variables

Env	Default	Description
NRE_WEB_LISTEN_ADDRESS	:9147	Address to listen on for web interface and telemetry
NRE_WEB_TELEMETRY_PATH	/metrics	Path under which to expose metrics
NRE_NGINX_SYSLOG_LISTENER	0.0.0.0:9514	Syslog listen address/socket for Nginx
NRE_HISTOGRAM_BUCKETS	.005,.01,.025,.05,.1,.25,.5,1,2.5,5,10	Buckets for the Prometheus histogram

Metrics

# HELP nginx_request_exporter_syslog_messages Current total syslog messages received.
# TYPE nginx_request_exporter_syslog_messages counter
# HELP nginx_request_exporter_syslog_parse_failure Number of errors while parsing syslog messages.
# TYPE nginx_request_exporter_syslog_parse_failure counter
# HELP nginx_request_time Nginx request log value for time
# TYPE nginx_request_time histogram

# HELP nginx_request_time_bucket
# TYPE nginx_request_time_bucket counter
# HELP nginx_request_time_sum
# TYPE nginx_request_time_sum counter
# HELP nginx_request_time_count
# TYPE nginx_request_time_count counter

How to get all metrics:

curl localhost:9147/metrics | grep -E "# HELP|# TYPE" | grep -v " go_"