Multiple Branches

# Multiple Branches (first-match-wins for non-Next rejoin)
#
# Multiple branches on a single filter, evaluated in
# order. Conditional branches with terminal or skip-to
# rejoin stop evaluation on first match. Unconditional
# branches with rejoin: next always fire as side-effects.
#
# Use case: guardrails categorizes requests as blocked
# or passed. Blocked requests terminate; passed requests
# get tagged and continue.
#
listeners:
  - name: web
    address: "127.0.0.1:8080"
    filter_chains: [main]

filter_chains:
  - name: main
    filters:
      # Stamp each request for tracing
      - filter: request_id

      # Guardrails: inspect headers. action: flag writes
      # results without rejecting, so branches decide.
      - filter: guardrails
        action: flag
        rules:
          - target: header
            name: "X-Danger"
            contains: "true"
        branch_chains:
          # Blocked content terminates with 403
          - name: blocked_path
            on_result:
              filter: guardrails
              result: blocked
            rejoin: terminal
            chains:
              - name: blocked_response
                filters:
                  - filter: static_response
                    status: 403

          # Passed content gets tagged and continues
          - name: passed_path
            on_result:
              filter: guardrails
              result: passed
            rejoin: next
            chains:
              - name: passed_processing
                filters:
                  - filter: headers
                    request_add:
                      - name: X-Guardrails
                        value: "passed"

      # All non-terminal paths converge here
      - filter: router
        name: routing
        routes:
          - path_prefix: "/"
            cluster: backend

      - filter: load_balancer
        clusters:
          - name: backend
            endpoints:
              - "127.0.0.1:3000"

insecure_options:
  allow_private_endpoints: true # example proxies to local backends