Envoy gRPC转REST配置失败：配置文件解析报错求助

问题场景 #

需要通过Envoy实现Java gRPC客户端与Scala REST服务的通信，gRPC请求指向/sample端点，但Envoy启动时配置解析失败。

原配置文件 #

static_resources:
  listeners:
    - name: listener_0
      address:
        socket_address:
          address: 0.0.0.0
          port_value: 8080
      filter_chains:
        - filters:
            - name: envoy.http_connection_manager
              typed_config:
                "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
                codec_type: auto
                stat_prefix: ingress_http
                route_config:
                  name: local_route
                  virtual_hosts:
                    - name: backend
                      domains: ["*"]
                      routes:
                        - match: { prefix: "/sample" }
                          route:
                            cluster: http4s_server_cluster
                http_filters:
                  - name: envoy.filters.http.grpc_json_transcoder
                    typed_config:
                      "@type": type.googleapis.com/envoy.extensions.filters.http.grpc_json_transcoder.v3.GrpcJsonTranscoder
                      proto_descriptor: "sample.proto"
                      services:
                        - proto_package: "com.proto"
                          proto_service: "SampleService"
                          json_name: "sample"
              use_remote_address: false
              access_log:
                - name: envoy.access_loggers.stdout
                  typed_config:
                    "@type": type.googleapis.com/envoy.extensions.access_loggers.stream.v3.StdoutAccessLog
  clusters:
    - name: http4s_server_cluster
      connect_timeout: 0.25s
      type: strict_dns
      lb_policy: round_robin
      http2_protocol_options: {}
      load_assignment:
        cluster_name: http4s_server_cluster
        endpoints:
          - lb_endpoints:
              - endpoint:
                  address:
                    socket_address:
                      address: 127.0.0.1
                      port_value: 8081 # 假设Scala REST服务运行在该端口

启动错误信息 #

[source/server/server.cc:997] exiting
Unable to parse JSON as proto (INVALID_ARGUMENT: invalid JSON in envoy.config.bootstrap.v3.Bootstrap @ static_resources.listeners[0].filter_chains[0].filters[0].typed_config.<any>.http_filters[0].typed_config.<any>.services[0]:  string, near  1:869 (offset  868): unexpected   character: '{'; expected '"'): {"static_resources":{"clusters":[{"connect_timeout":"0.25s","http2_protocol_options":{},"lb_policy":"round_robin","name":"http4s_server_cluster","load_assignment":{"cluster_name":"http4s_server_cluster","endpoints":[{"lb_endpoints":[{"endpoint":{"address":{"socket_address":{"address":"127.0.0.1","port_value":8081}}}}]}]},"type":"strict_dns"}],"listeners":[{"name":"listener_0","filter_chains":[{"filters":[{"name":"envoy.http_connection_manager","access_log":[{"name":"envoy.access_loggers.stdout","typed_config":{"@type":"type.googleapis.com/envoy.extensions.access_loggers.stream.v3.StdoutAccessLog"}}],"use_remote_address":false,"typed_config":{"route_config":{"name":"local_route","virtual_hosts":[{"routes":[{"route":{"cluster":"http4s_server_cluster"},"match":{"prefix":"/sample"}}],"name":"backend","domains":["*"]}]},"http_filters":[{"typed_config":{"services":[{"json_name":"sample","proto_package":"com.proto","proto_service":"SampleService"}],"@type":"type.googleapis.com/envoy.extensions.filters.http.grpc_json_transcoder.v3.GrpcJsonTranscoder","proto_descriptor":"sample.proto"},"name":"envoy.filters.http.grpc_json_transcoder"}],"codec_type":"auto","@type":"type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager","stat_prefix":"ingress_http"}}]}],"address":{"socket_address":{"address":"0.0.0.0","port_value":8080}}}]}}

错误原因 #

1. services字段格式错误：Envoy v3版本的GrpcJsonTranscoder配置中，services是字符串列表，格式为"包名.服务名"，原配置使用了v2版本的对象结构，导致解析失败。
2. 配置层级错误：use_remote_address和access_log是HttpConnectionManager的内部配置项，原配置将其放在了envoy.http_connection_manager filter的根层级，属于位置错误。
3. 多余的HTTP/2配置：后端是REST服务，通常使用HTTP/1.1，无需配置http2_protocol_options。
4. Protobuf描述符错误：proto_descriptor需要指向编译后的二进制描述符文件（如.pb），而非.proto源文件。
5. 缺少Router过滤器：Envoy HTTP连接管理器必须以Router过滤器结尾，原配置遗漏后会导致请求无法转发。

修正后的配置文件 #

static_resources:
  listeners:
    - name: listener_0
      address:
        socket_address:
          address: 0.0.0.0
          port_value: 8080
      filter_chains:
        - filters:
            - name: envoy.http_connection_manager
              typed_config:
                "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
                codec_type: auto
                stat_prefix: ingress_http
                use_remote_address: false
                access_log:
                  - name: envoy.access_loggers.stdout
                    typed_config:
                      "@type": type.googleapis.com/envoy.extensions.access_loggers.stream.v3.StdoutAccessLog
                route_config:
                  name: local_route
                  virtual_hosts:
                    - name: backend
                      domains: ["*"]
                      routes:
                        - match: { prefix: "/sample" }
                          route:
                            cluster: http4s_server_cluster
                http_filters:
                  - name: envoy.filters.http.grpc_json_transcoder
                    typed_config:
                      "@type": type.googleapis.com/envoy.extensions.filters.http.grpc_json_transcoder.v3.GrpcJsonTranscoder
                      # 替换为编译后的Protobuf二进制描述符文件路径
                      proto_descriptor: "sample.pb"
                      services:
                        - "com.proto.SampleService"
                      # 如需自定义方法的JSON名称映射，可添加以下配置
                      # mapping:
                      #   - grpc_method: "com.proto.SampleService/SampleMethod"
                      #     json_name: "sample"
                  - name: envoy.filters.http.router
                    typed_config:
                      "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router
  clusters:
    - name: http4s_server_cluster
      connect_timeout: 0.25s
      type: strict_dns
      lb_policy: round_robin
      load_assignment:
        cluster_name: http4s_server_cluster
        endpoints:
          - lb_endpoints:
              - endpoint:
                  address:
                    socket_address:
                      address: 127.0.0.1
                      port_value: 8081 # Scala REST服务的端口

关键修改说明 #

• 修正services格式：改为"com.proto.SampleService"字符串形式，符合v3 API规范。
• 调整配置层级：将use_remote_address和access_log移动到HttpConnectionManager的typed_config内部。
• 移除HTTP/2配置：删除http2_protocol_options，适配REST服务的HTTP/1.1协议。
• 添加Router过滤器：补充Envoy必须的请求转发过滤器。
• Protobuf描述符处理：先通过protoc编译生成二进制描述符：

  protoc --descriptor_set_out=sample.pb --include_imports sample.proto
  

验证步骤 #

1. 生成Protobuf二进制描述符文件。
2. 替换为修正后的配置文件。
3. 启动Envoy：envoy --config-path envoy_bridge.yaml。
4. 用Java gRPC客户端调用localhost:8080/sample，Envoy会自动将gRPC请求转成REST格式转发到Scala服务。

内容的提问来源于stack exchange，提问作者Mukhayyo Tashpulatova