Field Extraction Access Control

# Field Extraction for Tenant Access Control
#
# Extracts the "tenant_id" field from the JSON request body
# and promotes it to an X-Tenant-Id header. The router then
# matches on this header to enforce tenant isolation by
# directing each tenant's requests to dedicated backend
# clusters.
#
# Unknown or missing tenants fall through to a default
# cluster (which could be a rejection endpoint in
# production).
#
# Usage:
#   cargo run -p praxis-proxy -- -c examples/configs/payload-processing/field-extraction-access-control.yaml
#
#   curl -X POST http://localhost:8080/api/data \
#     -H "Content-Type: application/json" \
#     -d '{"tenant_id": "acme", "query": "..."}'
#
# This routes to the acme cluster. A request with
# "tenant_id": "globex" routes to the globex cluster.
# Missing or unrecognized tenants route to the default.

listeners:
  - name: api-gateway
    address: "0.0.0.0:8080" # dev value; binds all interfaces
    filter_chains:
      - extract-tenant
      - routing

filter_chains:
  - name: extract-tenant
    filters:
      - filter: json_body_field
        field: tenant_id
        header: X-Tenant-Id

  - name: routing
    filters:
      - filter: router
        routes:
          - path_prefix: "/"
            headers:
              x-tenant-id: "acme"
            cluster: acme
          - path_prefix: "/"
            headers:
              x-tenant-id: "globex"
            cluster: globex
          - path_prefix: "/"
            cluster: default
      - filter: load_balancer
        clusters:
          - name: acme
            endpoints:
              - "10.0.1.1:8080"
              - "10.0.1.2:8080"
          - name: globex
            endpoints:
              - "10.0.2.1:8080"
          - name: default
            endpoints:
              - "10.0.3.1:8080"