Merge pull request #1 from projectsesame/feat/conv

feat: convert between xml and json

Author: izturn

Diff for: Dockerfile

@@ -1,7 +1,9 @@
-FROM golang:1.21.6-bullseye
+FROM m.daocloud.io/docker.io/library/golang:1.21.6-bullseye
 
 SHELL ["/bin/bash", "-c"]
 
+RUN sed -i 's/htt[p|ps]:\/\/archive.ubuntu.com\/ubuntu\//mirror:\/\/mirrors.ubuntu.com\/mirrors.txt/g' /etc/apt/sources.list
+
 RUN apt-get update && apt-get -y upgrade \
     && apt-get autoremove -y \
     && rm -rf /var/lib/apt/lists/* \
@@ -10,19 +12,21 @@ RUN apt-get update && apt-get -y upgrade \
 WORKDIR /build
 
 COPY . .
+
+RUN go env -w GOPROXY=https://goproxy.cn,direct
 RUN go mod tidy \
     && go mod download \
     && go build -o /extproc
 
 
-FROM busybox
+FROM m.daocloud.io/docker.io/library/busybox:latest
 
 COPY --from=0 /extproc /bin/extproc
 RUN chmod +x /bin/extproc
 
-ARG EXAMPLE=payload-limit
+ARG EXAMPLE=xml-json-conv
 
 EXPOSE 50051
 
 ENTRYPOINT [ "/bin/extproc" ]
-CMD [ "payload-limit", "--log-stream", "--log-phases", "payload-limit", "32"  ]
+CMD [ "conv", "--log-stream", "--log-phases" ]

Diff for: README.md

@@ -1,6 +1,6 @@
-# envoy-extproc-payloadlimit-demo-go
+# envoy-extproc-xml-json-conv-demo-go
 
-This repository contains a demo application written in Go that demonstrates the usage of Envoy's External Processor (ExtProc) filter to do `payload limit` for POST request.
+This repository contains a demo application written in Go that demonstrates the usage of Envoy's External Processor (ExtProc) filter to convert the `data formats` for POST request.
 
 ## Overview
 
@@ -19,7 +19,7 @@ To get started with the demo application, follow these steps:
 
   1. Clone the repository:
      ```
-     git clone https://github.com/projectsesame/envoy-extproc-payloadlimit-demo-go.git
+     git clone https://github.com/projectsesame/envoy-extproc-xml-json-conv-demo-go.git
      ```
 
   2. Build the Go application:
@@ -29,7 +29,7 @@ To get started with the demo application, follow these steps:
 
   3. Run the application:
      ```
-     ./envoy-extproc-payloadlimit-demo-go payload-limit --log-stream --log-phases payload-limit 32
+     ./envoy-extproc-xml-json-conv-demo-go conv --log-stream --log-phases
      ```
 
 

Diff for: conv.go

@@ -0,0 +1,143 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"encoding/xml"
+	"errors"
+	"io"
+	"log"
+
+	mxj "github.com/clbanning/mxj/v2"
+	typev3 "github.com/envoyproxy/go-control-plane/envoy/type/v3"
+	ep "github.com/wrossmorrow/envoy-extproc-sdk-go"
+)
+
+type convRequestProcessor struct {
+	opts *ep.ProcessingOptions
+}
+
+func (s *convRequestProcessor) GetName() string {
+	return "xml-json-conv"
+}
+
+func (s *convRequestProcessor) GetOptions() *ep.ProcessingOptions {
+	return s.opts
+}
+
+func (s *convRequestProcessor) ProcessRequestHeaders(ctx *ep.RequestContext, headers ep.AllHeaders) error {
+	return ctx.ContinueRequest()
+}
+
+const (
+	kXML  = "xml"
+	kJSON = "json"
+)
+
+// detectFormat attempts to determine whether the data is JSON or XML.
+func detectFormat(data []byte) (string, error) {
+	if json.Valid(data) {
+		return kJSON, nil
+	}
+
+	if isValidXML(data) {
+		return kXML, nil
+	}
+
+	return "", errors.New("unknown format")
+}
+
+func isValidXML(input []byte) bool {
+	decoder := xml.NewDecoder(bytes.NewReader(input))
+	for {
+		err := decoder.Decode(new(any))
+		if err != nil {
+			return err == io.EOF
+		}
+	}
+}
+
+func (s *convRequestProcessor) ProcessRequestBody(ctx *ep.RequestContext, body []byte) error {
+	cancel := func(code int32) error {
+		return ctx.CancelRequest(code, map[string]ep.HeaderValue{}, typev3.StatusCode_name[code])
+	}
+
+	from, err := detectFormat(body)
+	if err != nil {
+		log.Println(err)
+		return cancel(400)
+	}
+
+	var data []byte
+
+	switch from {
+	case kJSON:
+		data, err = jsonToXML(body)
+	case kXML:
+		data, err = xmlToJSON(body)
+	default:
+		panic("never happen")
+	}
+
+	if err != nil {
+		log.Printf("convert data format is failed: %v", err)
+		return cancel(400)
+	}
+
+	return ctx.CancelRequest(200, map[string]ep.HeaderValue{}, string(data))
+}
+
+func (s *convRequestProcessor) ProcessRequestTrailers(ctx *ep.RequestContext, trailers ep.AllHeaders) error {
+	return ctx.ContinueRequest()
+}
+
+func (s *convRequestProcessor) ProcessResponseHeaders(ctx *ep.RequestContext, headers ep.AllHeaders) error {
+	return ctx.ContinueRequest()
+}
+
+func (s *convRequestProcessor) ProcessResponseBody(ctx *ep.RequestContext, body []byte) error {
+	return ctx.ContinueRequest()
+}
+
+func (s *convRequestProcessor) ProcessResponseTrailers(ctx *ep.RequestContext, trailers ep.AllHeaders) error {
+	return ctx.ContinueRequest()
+}
+
+func (s *convRequestProcessor) Init(opts *ep.ProcessingOptions, nonFlagArgs []string) error {
+	s.opts = opts
+	return nil
+}
+
+func (s *convRequestProcessor) Finish() {}
+
+// jsonToXML converts a JSON byte array to XML byte array.
+func jsonToXML(data []byte) ([]byte, error) {
+	mxj.XMLEscapeChars(true)
+	m, err := mxj.NewMapJsonReader(bytes.NewReader(data))
+	if err != nil {
+		return nil, err
+	}
+
+	buf := &bytes.Buffer{}
+	err = m.XmlIndentWriter(buf, "", "\t")
+	if err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+// xmlToJSON converts XML data to JSON.
+func xmlToJSON(data []byte) ([]byte, error) {
+	mxj.XMLEscapeChars(true)
+	m, err := mxj.NewMapXmlReader(bytes.NewReader(data))
+	if err != nil {
+		return nil, err
+	}
+
+	buf := &bytes.Buffer{}
+	err = m.JsonIndentWriter(buf, "", "\t")
+	if err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}

Diff for: deployment.yaml

@@ -2,24 +2,24 @@
 apiVersion: apps/v1
 kind: Deployment
 metadata:
-  name: payload-limit-demo
-  namespace: payload-limit-demo
+  name: xml-json-conv-demo
+  namespace: xml-json-conv-demo
   annotations:
 spec:
   replicas: 1
   selector:
     matchLabels:
-      app: payload-limit-demo
+      app: xml-json-conv-demo
   template:
     metadata:
       creationTimestamp: null
       labels:
-        app: payload-limit-demo
+        app: xml-json-conv-demo
     spec:
       containers:
-        - name: payload-limit-demo-container
+        - name: xml-json-conv-demo-container
           image: >-
-            release.daocloud.io/skoala/envoy-extproc-payloadlimit-demo-go@sha256:dcc5ba7aa2790e87b0cd46799363367b54202585794ebfe87248264f111e63d8
+            release.daocloud.io/skoala/envoy-extproc-xml-json-conv-demo-go:v0.0.1
           ports:
             - containerPort: 50051
               protocol: TCP
@@ -44,8 +44,8 @@ spec:
 apiVersion: v1
 kind: Service
 metadata:
-  name: payload-limit-demo
-  namespace: payload-limit-demo
+  name: xml-json-conv-demo
+  namespace: xml-json-conv-demo
   annotations:
 spec:
   ports:
@@ -54,7 +54,7 @@ spec:
       targetPort: 50051
       nodePort: 31928
   selector:
-    app: payload-limit-demo
+    app: xml-json-conv-demo
   type: NodePort
   sessionAffinity: None
   externalTrafficPolicy: Cluster

Diff for: envoy.yaml

@@ -2,7 +2,7 @@ static_resources:
   listeners:
     - name: listener
       address:
-        socket_address: {address: 0.0.0.0, port_value: 8000}
+        socket_address: {address: 0.0.0.0, port_value: 8080}
       filter_chains:
         - filters:
             - name: envoy.filters.network.http_connection_manager
@@ -35,7 +35,7 @@ static_resources:
                       "@type": type.googleapis.com/envoy.extensions.filters.http.ext_proc.v3.ExternalProcessor
                       grpc_service:
                         envoy_grpc:
-                          cluster_name: payload-limit
+                          cluster_name: xml-json-conv
                         timeout: 30s
                       failure_mode_allow: true
                       message_timeout: 0.2s
@@ -68,21 +68,21 @@ static_resources:
                 hostname: upstream
                 address:
                   socket_address:
-                    address: upstream
-                    port_value: 8000
-  - name: payload-limit
+                    address: 127.0.0.1 # if in a k8s cluster, use the service name
+                    port_value: 5678
+  - name: xml-json-conv
     dns_lookup_family: V4_ONLY
     lb_policy: LEAST_REQUEST
     load_assignment:
-      cluster_name: payload-limit
+      cluster_name: xml-json-conv
       endpoints:
       - lb_endpoints:
         - endpoint:
             address:
               socket_address:
-                address: payload-limit
+                address: 127.0.0.1 # if in a k8s cluster, use the service name
                 port_value: 50051
-            hostname: payload-limit
+            hostname: xml-json-conv
     type: LOGICAL_DNS
     typed_extension_protocol_options:
       envoy.extensions.upstreams.http.v3.HttpProtocolOptions:

Diff for: go.mod

@@ -1,8 +1,9 @@
-module github.com/projectsesame/envoy-extproc-payloadlimit-demo-go
+module github.com/projectsesame/envoy-extproc-xml-json-conv-demo-go
 
 go 1.21
 
 require (
+	github.com/clbanning/mxj/v2 v2.7.0
 	github.com/envoyproxy/go-control-plane v0.12.0
 	github.com/wrossmorrow/envoy-extproc-sdk-go v0.0.21
 )

Diff for: go.sum

@@ -1,3 +1,5 @@
+github.com/clbanning/mxj/v2 v2.7.0 h1:WA/La7UGCanFe5NpHF0Q3DNtnCsVoxbPKuyBNHWRyME=
+github.com/clbanning/mxj/v2 v2.7.0/go.mod h1:hNiWqW14h+kc+MdF9C6/YoRfjEJoR3ou6tn/Qo+ve2s=
 github.com/cncf/xds/go v0.0.0-20231128003011-0fa0005c9caa h1:jQCWAUqqlij9Pgj2i/PB79y4KOPYVyFYdROxgaCwdTQ=
 github.com/cncf/xds/go v0.0.0-20231128003011-0fa0005c9caa/go.mod h1:x/1Gn8zydmfq8dk6e9PdstVsDgu9RuyIIJqAaF//0IM=
 github.com/envoyproxy/go-control-plane v0.12.0 h1:4X+VP1GHd1Mhj6IB5mMeGbLCleqxjletLK6K0rbxyZI=

Diff for: main.go

@@ -16,7 +16,7 @@ type processor interface {
 }
 
 var processors = map[string]processor{
-	"payload-limit": &payloadLimitRequestProcessor{},
+	"conv": &convRequestProcessor{},
 }
 
 func parseArgs(args []string) (port *int, opts *ep.ProcessingOptions, nonFlagArgs []string) {
@@ -36,7 +36,6 @@ func parseArgs(args []string) (port *int, opts *ep.ProcessingOptions, nonFlagArg
 }
 
 func main() {
-
 	// cmd subCmd arg, arg2,...
 	args := os.Args
 	if len(args) < 2 {