External Authorization

The external authorization HTTP filter calls an external gRPC or HTTP service to check if the incoming HTTP request is authorized or not. If the request is deemed unauthorized then the request will be denied normally with 403 (Forbidden) response. Note that sending additional custom metadata from the authorization service to the upstream, or to the downstream is also possible. This is explained in more details at HTTP filter.

Tip

It is recommended that this filter is configured first in the filter chain so that requests are authorized prior to the rest of filters processing the request.

The content of the requests that are passed to an authorization service is specified by CheckRequest.

The HTTP filter, using a gRPC/HTTP service, can be configured as follows. You can see all the configuration options at HTTP filter.

Configuration Examples

A sample filter configuration for a gRPC authorization server:

http_filters:
  - name: envoy.ext_authz
    config:
      grpc_service:
         envoy_grpc:
           cluster_name: ext-authz
clusters:
  - name: ext-authz
    type: static
    http2_protocol_options: {}
    hosts:
      - socket_address: { address: 127.0.0.1, port_value: 10003 }

A sample filter configuration for a raw HTTP authorization server:

http_filters:
  - name: envoy.ext_authz
    config:
      http_service:
          server_uri:
            uri: 127.0.0.1:10003
            cluster: ext-authz
            timeout: 0.25s
            failure_mode_allow: false
clusters:
  - name: ext-authz
    connect_timeout: 0.25s
    type: logical_dns
    lb_policy: round_robin
    hosts:
      - socket_address: { address: 127.0.0.1, port_value: 10003 }

Statistics

The HTTP filter outputs statistics in the cluster.<route target cluster>.ext_authz. namespace.

Name Type Description
ok Counter Total responses from the filter.
error Counter Total errors contacting the external service.
denied Counter Total responses from the authorizations service that were to deny the traffic.
failure_mode_allow Counter Total requests that were error(s) but were allowed through because of failure_mode_allow set to true.