Rewriter

3.3.0

The Rewriter can dynamically modify HTTP request and response bodies. Unlike the built-in rewriteBody/rewriteResponseBody/rewriteRequestBody rules (based on regex matching and replacement), the rewriter provides more flexible modification capabilities through external plugin services.

Using a Rewriter

The rewriter can be configured at the service level and referenced in services:

services:
- name: service-0
  addr: :8080
  handler:
    type: auto
  listener:
    type: tcp
  rewriter: rewriter-0

rewriters:
- name: rewriter-0
  plugin:
    type: grpc
    addr: 127.0.0.1:8000

Plugin Configuration

plugin.type (string, default=grpc)

plugin type: grpc or http.

plugin.addr (string, required)

plugin server address.

plugin.token (string)

credentials for server-side authentication.

plugin.tls (object)

enable TLS encryption for the plugin connection.

plugin.timeout (duration)

request timeout.

HTTP Plugin

rewriters:
- name: rewriter-0
  plugin:
    type: http
    addr: http://127.0.0.1:8000/rewrite

Request format:

{"data":"<base64 original content>","metadata":<metadata>}

Response format:

{"ok":true,"data":"<base64 modified content>"}

Node-Level Rewriter

The rewriter can also be used in each forwarder node's rewriteBody/rewriteResponseBody/rewriteRequestBody rules:

forwarder:
  nodes:
  - name: target-0
    addr: example.com:80
    http:
      rewriteResponseBody:
      - type: text/html
        rewriter: rewriter-0
      rewriteRequestBody:
      - type: application/json
        rewriter: rewriter-0

When a rule has rewriter set, the body modification is delegated to the rewriter plugin, and the match/replacement fields are ignored.

The rewriter can be combined with type (content-type filtering) to send different body types to different rewriters.

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