public-api

The public-api plugin exposes an internal API endpoint, making it publicly accessible. One of the primary use cases of this plugin is to expose internal endpoint created by other plugins.

Example

Expose Prometheus Metrics at Custom Endpoint

The following example demonstrates how you can disable the Prometheus export server that, by default, exposes an endpoint on port 9091, and expose APISIX Prometheus metrics on a new public API endpoint on port 9080, which APISIX uses to listen to other client requests.

You will also configure the route such that the internal endpoint /apisix/prometheus/metrics is exposed at a custom endpoint.

caution

If a large quantity of metrics are being collected, the plugin could take up a significant amount of CPU resources for metric computations and negatively impact the processing of regular requests.

To address this issue, APISIX uses privileged agent and offloads the metric computations to a separate process. This optimization applies automatically if you use the metric endpoint configured in the configuration files, as demonstrated above. If you expose the metric endpoint with the public-api plugin, you will not benefit from this optimization.

Disable the Prometheus export server in the configuration file and reload APISIX for changes to take effect:

conf/config.yaml
plugin_attr:
  prometheus:
    enable_export_server: false

Next, create a route with public-api plugin and expose a public API endpoint for APISIX metrics:

curl "http://127.0.0.1:9180/apisix/admin/routes/prometheus-metrics" -X PUT \
  -H "X-API-KEY: ${ADMIN_API_KEY}" \
  -d '{
    "uri": "/prometheus_metrics",
    "plugins": {
      "public-api": {
        "uri": "/apisix/prometheus/metrics"
      }
    }
  }'

❶ Set the route uri to the custom endpoint path.

❷ Set the plugin uri to the internal endpoint to be exposed.

Send a request to the custom metrics endpoint:

curl "http://127.0.0.1:9080/prometheus_metrics"

You should see an output similar to the following:

# HELP apisix_http_requests_total The total number of client requests since APISIX started
# TYPE apisix_http_requests_total gauge
apisix_http_requests_total 1
# HELP apisix_nginx_http_current_connections Number of HTTP connections
# TYPE apisix_nginx_http_current_connections gauge
apisix_nginx_http_current_connections{state="accepted"} 1
apisix_nginx_http_current_connections{state="active"} 1
apisix_nginx_http_current_connections{state="handled"} 1
apisix_nginx_http_current_connections{state="reading"} 0
apisix_nginx_http_current_connections{state="waiting"} 0
apisix_nginx_http_current_connections{state="writing"} 1
...

public-api

Example​

Expose Prometheus Metrics at Custom Endpoint​

Example

Expose Prometheus Metrics at Custom Endpoint