traefik/docs/content/reference/routing-configuration/http/middlewares/opa.md

title	description
Open Policy Agent	Traefik Hub API Gateway - The Open Policy Agent (OPA) middleware that allows you to restrict access to your services.

!!! info "Traefik Hub Feature" This middleware is available exclusively in Traefik Hub. Learn more about Traefik Hub's advanced features.

Traefik Hub comes with an Open Policy Agent middleware that allows you to restrict access to your services. It also allows you to enrich request headers with data extracted from policies. The OPA middleware works as an OPA agent.

!!! note "OPA Version"

This middleware uses the [v1.3.0 of the OPA specification](https://www.openpolicyagent.org/docs).

Configuration Example

apiVersion: traefik.io/v1alpha1
kind: Middleware
metadata:
  name: opa-allow-jwt-claim
  namespace: apps
spec:
  plugin:
    opa:
      policy: |
        package example.policies

        allow {
          [_, encoded] := split(input.headers.Authorization, " ")
          [header, payload, signature] = io.jwt.decode(encoded)
          payload["email"] == "bibi@example.com"
        }        
      forwardHeaders:
        Group: data.package.grp

apiVersion: traefik.io/v1alpha1
kind: Middleware
metadata:
  name: opa-deny-json
  namespace: apps
spec:
  plugin:
    opa:
      policy: |
        package example.policies

        default allow = false

        json_content {
          input.headers["Accept"] == "application/json"
        }

        allow {
          not json_content
        }        
      allow: data.example.policies.allow

Configuration Options

Field	Description	Default	Required
policy	Path or the content of a policy file.	""	No (one of policy or bundlePath must be set)
bundlePath	The bundlePath option should contain the path to an OPA bundle.	""	No (one of policy or bundlePath must be set)
allow	The allow option sets the expression to evaluate that determines if the request should be authorized.	""	No (one of allow or forwardHeaders must be set)
forwardHeaders	The forwardHeaders option sets the HTTP headers to add to requests and populates them with the result of the given expression.	""	No (one of allow or forwardHeaders must be set)

{!traefik-for-business-applications.md!}