Metadata API

The edge functions on Edge Firewall have access to a set of metadata that can be manipulated to:

Filter and manage access to your application.
Apply specific logic in different scenarios.

This reference documentation describes the available metadata and their usage.

GeoIP

The GeoIP metadata provides information on the geographical location of the client based on IP data.

Name	Description
geoip_asn	Autonomous system number
geoip_city	City code
geoip_city_continent_code	City continent code information
geoip_city_country_code	City country code
geoip_city_country_name	City country name
geoip_continent_code	Continent code
geoip_country_code	Country code
geoip_country_name	Country name
geoip_region	Region code
geoip_region_name	Region name

Remote

The Remote metadata provides details about the remote client’s IP address and TCP port.

Name	Description
remote_addr	Remote (client) IP address
remote_port	Remote (client) TCP port
remote_user	User informed in the URL. Example: user in http://user@site.com/

Server

The Server metadata provides details about the protocol being used in the request.

Name	Description
server_protocol	Protocol being used in the request. Example: HTTP/1.1

TLS

The TLS metadata provides details about TLS certificates.

Name	Description
ssl_cipher	TLS cipher used
ssl_protocol	TLS protocol used

Usage

You can access the metadata through event.request.metadata["remote_addr"], as in:

    let ip = event.request.metadata["remote_addr"] // Accessing the remote address

Implementation

In the code sample below:

The remote address is accessed.
It’s verified if this address is in a network list.
If it’s in the network list, the request is denied.

     addEventListener("firewall", (event) => {

      let ip = event.request.metadata["remote_addr"] // Accessing the remote address

      try {
        let found = Azion.networkList.contains(String(networkListId), ip); // Checking if the ip is in the list
        if (found) {
          event.deny(); // If it's in the list, deny the request
        }
      } catch (err) {
        event.console.error(`Error: `, err.stack);
      }
    });