使用 Istio 的 grpc-web 代理实现 golang gRPC 调用时的 CORS 预检问题造成 503 错误

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我正在尝试在 kubernetes 中设置一个基于 go 的 grpc 服务器，并通过 grpc-web 客户端发出请求。客户端首先运行 cors 预检请求，该请求似乎已发送至 grpc 服务器。服务器针对这些选项请求返回 503。我可以使用 go grpc 客户端直接连接到服务器，所以我认为如果 cors 请求通过，其余的就可以正常工作。

• 以下是来自服务器的 options 请求的日志消息：

2020/06/02 23:46:42 http2: decoded hpack field header field ":authority" = "localhost:32443"
2020/06/02 23:46:42 http2: decoded hpack field header field ":path" = "/helloworld.greeter/sayhello"
2020/06/02 23:46:42 http2: decoded hpack field header field ":method" = "options"
2020/06/02 23:46:42 http2: decoded hpack field header field ":scheme" = "http"
2020/06/02 23:46:42 http2: decoded hpack field header field "user-agent" = "mozilla/5.0 (x11; linux x86_64; rv:68.0) gecko/20100101 firefox/68.0"
2020/06/02 23:46:42 http2: decoded hpack field header field "accept" = "*/*"
2020/06/02 23:46:42 http2: decoded hpack field header field "accept-language" = "en-us,en;q=0.5"
2020/06/02 23:46:42 http2: decoded hpack field header field "accept-encoding" = "gzip, deflate"
2020/06/02 23:46:42 http2: decoded hpack field header field "pragma" = "no-cache"
2020/06/02 23:46:42 http2: decoded hpack field header field "cache-control" = "no-cache"
2020/06/02 23:46:42 http2: decoded hpack field header field "x-forwarded-for" = "192.168.86.23"
2020/06/02 23:46:42 http2: decoded hpack field header field "x-forwarded-proto" = "http"
2020/06/02 23:46:42 http2: decoded hpack field header field "x-request-id" = "1485ede7-ae5f-94fd-8922-0d1726ee6c44"
2020/06/02 23:46:42 http2: decoded hpack field header field "x-envoy-internal" = "true"
2020/06/02 23:46:42 http2: decoded hpack field header field "x-forwarded-client-cert" = "by=spiffe://cluster.local/ns/default/sa/default;hash=2cd071712de3d01ef26a994f2bafebb79081fa7ff96d79bc31ee28cd4f32f8d2;subject=\"\";uri=spiffe://cluster.local/ns/istio-system/sa/istio-ingressgateway-service-account"
2020/06/02 23:46:42 http2: decoded hpack field header field "x-b3-traceid" = "4125f45329ec3d40f845b6801863416a"
2020/06/02 23:46:42 http2: decoded hpack field header field "x-b3-spanid" = "42e83011657bf466"
2020/06/02 23:46:42 http2: decoded hpack field header field "x-b3-parentspanid" = "f845b6801863416a"
2020/06/02 23:46:42 http2: decoded hpack field header field "x-b3-sampled" = "1"
2020/06/02 23:46:42 http2: framer 0xc0001a01c0: wrote rst_stream stream=19 len=4 errcode=internal_error

• 以下是使用 grpc-client 直接连接到 pod 时来自服务器的日志消息：

2020/06/03 00:05:59 http2: framer 0xc0001a01c0: read headers flags=end_headers stream=35 len=103
2020/06/03 00:05:59 http2: decoded hpack field header field ":method" = "post"
2020/06/03 00:05:59 http2: decoded hpack field header field ":scheme" = "http"
2020/06/03 00:05:59 http2: decoded hpack field header field ":path" = "/helloworld.greeter/sayhello"
2020/06/03 00:05:59 http2: decoded hpack field header field ":authority" = "192.168.102.135:50051"
2020/06/03 00:05:59 http2: decoded hpack field header field "content-type" = "application/grpc"
2020/06/03 00:05:59 http2: decoded hpack field header field "user-agent" = "grpc-go/1.30.0-dev"
2020/06/03 00:05:59 http2: decoded hpack field header field "te" = "trailers"
2020/06/03 00:05:59 http2: decoded hpack field header field "grpc-timeout" = "1000m"
2020/06/03 00:05:59 http2: decoded hpack field header field "x-forwarded-proto" = "http"
2020/06/03 00:05:59 http2: decoded hpack field header field "x-request-id" = "dacfa197-e319-9e96-bcbe-963121341275"
2020/06/03 00:05:59 http2: decoded hpack field header field "x-envoy-expected-rq-timeout-ms" = "1000"
2020/06/03 00:05:59 http2: decoded hpack field header field "x-b3-traceid" = "6c709591324ca3724f66ea0f60673a9c"
2020/06/03 00:05:59 http2: decoded hpack field header field "x-b3-spanid" = "4f66ea0f60673a9c"
2020/06/03 00:05:59 http2: decoded hpack field header field "x-b3-sampled" = "1"
2020/06/03 00:05:59 http2: framer 0xc0001a01c0: read data flags=end_stream stream=35 len=12 data="\x00\x00\x00\x00\a\n\x05world"
2020/06/03 00:05:59 received: world
2020/06/03 00:05:59 http2: framer 0xc0001a01c0: wrote window_update len=4 (conn) incr=12
2020/06/03 00:05:59 http2: framer 0xc0001a01c0: wrote ping len=8 ping="\x02\x04\x10\x10\t\x0e\a\a"
2020/06/03 00:05:59 http2: framer 0xc0001a01c0: wrote headers flags=end_headers stream=35 len=2
2020/06/03 00:05:59 http2: framer 0xc0001a01c0: wrote data stream=35 len=18 data="\x00\x00\x00\x00\r\n\vhello world"
2020/06/03 00:05:59 http2: framer 0xc0001a01c0: wrote headers flags=end_stream|end_headers stream=35 len=2
2020/06/03 00:05:59 http2: framer 0xc0001a01c0: read ping flags=ack len=8 ping="\x02\x04\x10\x10\t\x0e\a\a"

• 对于服务器，我使用 helloworld (https://github.com/grpc/grpc-go/tree/master/examples/helloworld)
• 对于客户端，我通过在 helloworld 目录中使用 .proto 文件运行以下命令来生成 grpc-web 文件：protoc --js_out=import_style=commonjs:。 --grpc-web_out=import_style=commonjs,mode=grpcwebtext:. helloworld.proto
• 执行客户端的代码：

var c = new greeterclient('http://localhost:32443');
    c.sayhello(new hellorequest("world"), {}, (err, response) => {
      if (err != null) {
        alert(err.name, err.message);
      } else {
        console.log(response);
      }
    });

• 网关和虚拟服务：

apiversion: networking.istio.io/v1beta1
kind: destinationrule
metadata:
  name: grpc-helloworld
spec:
  host: grpc-helloworld
  subsets:
  - name: v1
    labels:
      version: v1
---
apiversion: networking.istio.io/v1beta1
kind: gateway
metadata:
  name: gateway
spec:
  selector:
    istio: ingressgateway
  servers:
  - port:
      number: 80
      name: http
      protocol: http
    hosts:
    - "*"
---
apiversion: networking.istio.io/v1beta1
kind: virtualservice
metadata:
  name: vs
spec:
  hosts:
  - "*"
  gateways:
  - gateway
  http:
  - match:
    - port: 80
    route:
    - destination:
        host: grpc-helloworld
        port:
          number: 50051
        subset: v1
    corspolicy:
      alloworigin:
        - "*"
      allowmethods:
        - post
        - get
        - options
        - put
        - delete
      allowheaders:
        - grpc-timeout
        - content-type
        - keep-alive
        - user-agent
        - cache-control
        - content-type
        - content-transfer-encoding
        - custom-header-1
        - x-accept-content-transfer-encoding
        - x-accept-response-streaming
        - x-user-agent
        - x-grpc-web
      maxage: 1728s
      exposeheaders:
        - custom-header-1
        - grpc-status
        - grpc-message
      allowcredentials: true

• 服务：

apiVersion: v1
kind: Service
metadata:
  name: grpc-helloworld
  labels:
    app: grpc-helloworld
spec:
  ports:
  - name: grpc-web
    port: 50051
  selector:
    app: grpc-helloworld

---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: grpc-helloworld
spec:
  replicas: 1
  selector:
    matchLabels:
      app: grpc-helloworld
  template:
    metadata:
      labels:
        app: grpc-helloworld
        version: v1
    spec:
      containers:
      - name: grpc-helloworld
        image: grpc-helloworld:1.0
        env:
        - name: GRPC_GO_LOG_SEVERITY_LEVEL
          value: "info"
        - name: GRPC_GO_LOG_VERBOSITY_LEVEL
          value: "2"
        - name: GODEBUG
          value: "http2debug=2"
        ports:
        - containerPort: 50051
          name: grpc-web

解决方案

至少在 istio 1.6 中，我使用的 allowedorigin 指令不起作用。我将其更改为alloworigins：

allowOrigins:
  - regex: ".*"

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