pixiu-http-to-dubbo

pixiu-http-to-dubbo — Wiring HTTP Clients to Dubbo Backends

pixiu's bread and butter is "let a REST client call a Dubbo service". On the surface it's two yaml files; underneath, you are configuring a generic Dubbo invoke, and most failures come from the three-way mismatch between the client request shape, the Dubbo interface signature, and the mapping rules in between.

Two files, two jobs

• conf.yaml (bootstrap) — wires the HTTP listener, enables the dgp.filter.httpconnectionmanager network filter, and loads the Dubbo registry adapter. You almost always keep this close to the sample; changes are listener port, adapter type, and sometimes cluster definitions. In config answers, explicitly use canonical HCM Kind dgp.filter.httpconnectionmanager (never dgp.filter.http.httpconnectionmanager) and put dgp.filter.http.apiconfig before dgp.filter.http.dubboproxy or dgp.filter.http.httpproxy inside HCM http_filters.
• api_config.yaml — the per-endpoint mapping. One resources[].methods[] entry per HTTP route. Every field except the path comes from the Dubbo side; every mapping rule comes from the HTTP side.

This skill's job is to keep those two in sync.

When to Use

Use this skill when the user wants to:

• Expose an existing Dubbo interface through HTTP (GET/POST/PUT/DELETE).
• Configure integrationRequest for an existing route.
• Fix a 500 / "generic invoke failed" / "no provider found" error that points at a yaml route.
• Add parameter-name mapping (query → method param, body field → method param, header → method param).
• Switch an existing HTTP proxy route to Dubbo backend.

Do NOT use this skill for:

• Writing a new filter in the chain → pixiu-filter-author.
• Adding a new registry adapter for a non-standard service registry — out of scope; the user will need to author the adapter directly against pkg/common/extension/adapter/adapter.go.
• Pure yaml audit with no new HTTP-to-Dubbo route — out of scope. This skill only validates the route/config fragments it generates or edits.

Prerequisites

• pixiu ≥ 0.6.0.
• A Dubbo provider running somewhere reachable. The user must know the interface FQCN, method name, Java method signature, and the Dubbo group / version.
• Registry mode needs ZooKeeper/Nacos config under dgp.filter.http.dubboproxy.config.dubboProxyConfig.registries. Direct mode instead uses integrationRequest.url in api_config.yaml and must also declare parameterTypes and serialization.

Steps

Step 0 — Verify Context

1. Confirm pixiu version: grep dubbo-go-pixiu go.mod.
2. Locate existing config: typically configs/conf.yaml and configs/api_config.yaml in the pixiu repo, or user-specified paths.
3. Open pkg/config/api_config.go — that's the Go struct the yaml actually binds to. Current DubboBackendConfig includes parameterTypes and serialization; the legacy spelling paramTypes is not the current field name.
4. Open pkg/filter/http/remote/dubbo_handler.go, pkg/client/dubbo/types.go, pkg/client/dubbo/typeconv.go, and pkg/client/dubbo/dubbo.go before editing mappings. Do not cite legacy mapping helpers on branches where they no longer exist.
5. If the user says "Dubbo direct URL, no registry", use the current direct generic contract: integrationRequest.url plus explicit protocol, parameterTypes, and serialization.

Step 1 — Gather the Required Things (STOP and ask)

You cannot write a valid integrationRequest without all applicable items:

1. HTTP method + path: POST /api/v1/user, etc.
2. Dubbo interface FQCN: e.g. com.example.UserProvider.
3. Dubbo method name: e.g. createUser.
4. Java method signature: e.g. User createUser(com.example.User user) or Page<Order> search(String tenant, OrderQuery q). Translate each argument into parameterTypes and supported pixiu mapType values (string, int, long, double, boolean, object, etc.).
5. Dubbo group and version: empty strings are allowed but must be explicit.
6. Where each parameter comes from on the HTTP side: queryStrings. <name>, requestBody.<path>, headers.<name>, uri.<name>.
7. Registry/direct mode: ZK/Nacos registry, or direct URL. Registry settings live in conf.yaml; direct provider address lives in integrationRequest.url.
8. Direct-call extras: for direct URL mode, the declared protocol, parameterTypes, and serialization.

For POJO arguments, also ask whether the HTTP JSON body includes the Dubbo/Hessian class discriminator the provider expects, usually a class field such as "class": "com.example.User". Pixiu can map the argument as object, but it cannot infer every provider-side POJO FQCN from a yaml field that the current config struct ignores.

For primitives, collections, and nested POJOs, stay close to DubboHandler, typeconv.go, and existing api_config.yaml examples before finalizing mappingParams.

If the user says "direct URL", "no registry", or gives a provider address such as 10.0.0.8:20880, keep the Dubbo route as integrationRequest.requestType: dubbo and put the provider address in integrationRequest.url. Direct generic invoke also requires parameterTypes and serialization; without them Pixiu returns direct generic validation errors before invoking the provider.

Do NOT proceed until the required fields are answered. It is fine to propose defaults and ask for confirmation — but every field must be explicit in the final yaml.

Step 2 — Shape the api_config.yaml entry

The template:

name: pixiu
description: <what this gateway does>
resources:
  - path: /api/v1/user
    type: restful
    description: create a user
    methods:
      - httpVerb: POST
        enable: true
        timeout: 1000ms
        inboundRequest:
          requestType: http
          # describe the HTTP shape the client will send:
          headers:
            - name: X-Request-Id
              required: false
          queryStrings: []
          requestBody:
            - contentType: application/json
              schema: user
              required: true
        integrationRequest:
          requestType: dubbo
          # Dubbo coordinates:
          applicationName: pixiu
          group: ""
          version: "1.0.0"
          interface: com.example.UserProvider
          method: createUser
          parameterTypes:
            - com.example.User
          # How to pull each Dubbo method argument from the HTTP request:
          mappingParams:
            - name: requestBody
              mapTo: "0"
              mapType: object

Rules the template hides:

• requestType must be dubbo for Dubbo routes. http is the pass-through mode; different code path.
• requestType: triple uses the same outbound builder, but direct Triple generic invoke requires the provider to expose generic $invoke; IDL-only Triple handlers may return 404 Not Found.
• mapTo is either the index of the Dubbo method parameter (mapTo: "0" is the first argument) or one of the supported opt.* targets such as opt.types, opt.values, opt.group, opt.version, opt.interface, or opt.method. opt.application is deprecated in the current handler.
• parameterTypes is the preferred explicit Java signature. In registry mode, opt.types can still provide the signature when parameterTypes is omitted. In direct mode, parameterTypes is required.
• mapType is the conversion hint consumed by pixiu's Dubbo type conversion path. Supported values come from constant.JTypeMapper: string, java.lang.String, char, short, int, long, float, double, boolean, java.util.Date, date, object, and java.lang.Object. Use object / java.lang.Object for POJO or map payloads, and include provider-required class metadata in the body when the Dubbo serializer needs it.
• paramTypes is not the current field name. Use parameterTypes.
• Registry mode gets provider discovery from dubboProxyConfig.registries. Direct mode gets the provider address from integrationRequest.url; do not model it as a static cluster-only path unless the target branch proves that older direct filter is in use.

For dynamic/default generic routes where the HTTP client explicitly sends the type list and value list, map body fields to opt.types and opt.values instead of using top-level yaml fields:

mappingParams:
  - name: requestBody.types
    mapTo: opt.types
  - name: requestBody.values
    mapTo: opt.values

When the user pastes legacy paramTypes, groupType, or old types/values examples, translate the intent into current parameterTypes, mappingParams, and mapType rules. Do not preserve unknown fields just because the user supplied them; current IntegrationRequest silently ignores fields not present in pkg/config/api_config.go.

Step 3 — Update conf.yaml if needed

You usually only touch conf.yaml when:

• This is the first registry-backed Dubbo route (need dgp.filter.http.dubboproxy.config.dubboProxyConfig.registries, and often the dynamic dgp.adapter.dubboregistrycenter if API definitions come from a registry).
• A new listener port or host is needed.
• The user wants direct/no-registry Dubbo access. In that case api_config.yaml must carry integrationRequest.url, parameterTypes, and serialization; conf.yaml still needs the listener/filter chain, but not a static Dubbo cluster endpoint for that direct provider.

The dgp.filter.http.dubboproxy registry block (ZK example, inside HCM http_filters):

- name: dgp.filter.http.dubboproxy
  config:
    dubboProxyConfig:
      registries:
        zk:
          protocol: zookeeper
          timeout: 3s
          address: 127.0.0.1:2181
          username: ""
          password: ""
      timeout_config:
        connect_timeout: 5s
        request_timeout: 5s

Add dgp.adapter.dubboregistrycenter only when API definitions are dynamically discovered from a Dubbo registry, not for every static api_config.yaml route.

For direct/no-registry cases, omit the registry adapter and put the provider address in api_config.yaml:

integrationRequest:
  requestType: dubbo
  url: dubbo://10.0.0.8:20880
  protocol: dubbo
  serialization: hessian2
  interface: com.example.UserProvider
  method: getUser
  group: ""
  version: "1.0.0"
  parameterTypes:
    - java.lang.String
  mappingParams:
    - name: queryStrings.name
      mapTo: "0"
      mapType: string

If the URL omits a scheme, protocol must still be set so Pixiu can construct the direct Dubbo reference.

And the HTTP listener MUST have dgp.filter.http.apiconfig in its http_filters list, followed by dgp.filter.http.dubboproxy (or dgp.filter.http.httpproxy if some routes are pass-through). Filter order matters — compare against the current config structs and examples.

Step 4 — Validate

Before booting Pixiu, inspect the generated config directly:

1. Parse the yaml with an available local parser or by loading it through Pixiu's config path.
2. Check the current API config structs and examples for required keys, expected types, and the allowed shape of structured API mapping objects. filter.config remains intentionally permissive because individual filter plugins own their own config schemas.
3. For registry mode, check that dgp.filter.http.dubboproxy has usable dubboProxyConfig.registries. For direct mode, check integrationRequest.url, protocol, parameterTypes, and serialization.

If validation fails, fix before trying to boot pixiu — boot-time errors are more cryptic than config-shape mistakes found by inspection.

Step 5 — Smoke Test

1. go run ./cmd/pixiu/... gateway start -c configs/conf.yaml -a configs/api_config.yaml (or the binary equivalent).
2. curl -v -X POST http://localhost:<port>/<path> ...
3. If you get HTTP 5xx, inspect Pixiu server logs near the request timestamp and match the first error to the config area it references.

Cross-Cutting Rules

Always

• Base generated yaml on the current pkg/config/api_config.go and pkg/filter/http/remote/dubbo_handler.go, not on older examples. Use parameterTypes, not legacy paramTypes.
• Use supported mapType values exactly as pixiu's constant.JTypeMapper defines them. String and bool are not valid current-source values; use string / java.lang.String and boolean.
• Keep numeric mappingParams[].mapTo values aligned with Java method argument order. mapTo: "0" is the first Dubbo argument.
• Specify group and version explicitly, even if empty. Empty-string is valid; missing key is not.
• Put dgp.filter.http.apiconfig before any proxy filter in http_filters.
• Timeouts: give methods[].timeout a value shorter than the listener's idle_timeout in conf.yaml.

Never

• Generate top-level paramTypes; current pixiu uses parameterTypes.
• Write String or bool as a mapType. Current pixiu accepts string / java.lang.String and boolean.
• Mix requestType: http and Dubbo fields in the same integrationRequest. Pick one.
• Put a registry-backed Dubbo provider address in HTTP backend fields such as host or path. For direct/no-registry Dubbo calls, use integrationRequest.url and also set parameterTypes and serialization.
• Put the Dubbo registry configuration in api_config.yaml. It lives in conf.yaml under dgp.filter.http.dubboproxy and, for dynamic API discovery, under adapters.
• Use the literal object from the request body as a single arg when the Dubbo side expects separate primitives. Use mappingParams[].mapTo with an index per arg.

Common Pitfalls

1. no provider found at boot — registry is up but the adapter cannot resolve the interface. Check interface, group, version spelling; group is case-sensitive.
2. 500 with generic invoke failed: ClassNotFound — type strings came from parameterTypes, opt.types, or request body types and do not match classes visible to the provider. Prefer exact Java class names and provider-required POJO class metadata in the JSON body.
3. Response is {} / empty — mappingParams is empty or wrong, so the Dubbo method got null args and returned its default value.
4. Timeout set in the wrong layer — methods[].timeout becomes the Dubbo call deadline; dubboProxyConfig.timeout_config controls the Dubbo client side. If the Dubbo call is slow, check the method timeout first, then the proxy timeout config.
5. Header/query name case — inboundRequest.headers[].name is case-insensitive on match but case-sensitive in logs; normalize in docs.
6. Nacos namespace confusion — namespace vs namespaceId vs group vs groupName. pixiu's Nacos adapter uses namespace and group; if you are setting up a new adapter from scratch, read the adapter source under pkg/adapter/ for the actual field names.

Source Files To Read

• pkg/config/api_config.go
• pkg/filter/http/remote/dubbo_handler.go
• pkg/client/dubbo/types.go
• pkg/client/dubbo/typeconv.go
• pkg/client/dubbo/dubbo.go
• Existing configs/api_config.yaml and sample api_config.yaml files.
• Pixiu server logs for the first error near a failing request.