Merge pull request #8 from lukaszbudnik/cors-support

added CORS support

.github/workflows/docker-image.yml

@@ -0,0 +1,18 @@
+name: Docker Image CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Build the Docker image
+      run: docker build . --file Dockerfile --tag yosoy-local:$(date +%s)

.github/workflows/go.yml

@@ -0,0 +1,25 @@
+name: Go
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Set up Go
+      uses: actions/setup-go@v2
+      with:
+        go-version: 1.15
+
+    - name: Build
+      run: go build -v ./...
+
+    - name: Test
+      run: go test -v ./...

.gitignore

@@ -0,0 +1,2 @@
+debug.test
+yosoy

Dockerfile

@@ -1,13 +1,12 @@
-FROM golang:1.13.5-alpine3.10 as builder
+FROM golang:1.15.7-alpine3.13 as builder
 
 LABEL maintainer="Łukasz Budnik lukasz.budnik@gmail.com"
 
 # build yosoy
-RUN apk add git
-RUN git clone https://github.com/lukaszbudnik/yosoy.git
+ADD . /go/yosoy
 RUN cd /go/yosoy && go build
 
-FROM alpine:3.10
+FROM alpine:3.13
 COPY --from=builder /go/yosoy/yosoy /bin
 
 # register entrypoint

README.md

@@ -1,4 +1,4 @@
-# yosoy
+# yosoy ![Go](https://github.com/lukaszbudnik/yosoy/workflows/Go/badge.svg) ![Docker](https://github.com/lukaszbudnik/yosoy/workflows/Docker%20Image%20CI/badge.svg)
 
 yosoy is a HTTP service for stubbing and prototyping distributed applications. It is a service which will introduce itself to the caller and print some useful information about its environment. "Yo soy" in español means "I am".
 
@@ -11,19 +11,24 @@ Typical use cases include:
 * testing HTTP caching
 * stubbing and prototyping distributed applications
 
-yosoy will provide information like:
+## API
 
-* Request URI
-* Hostname
-* Remote IP
-* How many times it was called
-* HTTP headers
-* Env variables if `YOSOY_SHOW_ENVS` is set to `true`, `yes`, `on`, or `1`
-* Files' contents if `YOSOY_SHOW_FILES` is set to a comma-separated list of (valid) files
+yosoy responds to all requests with a JSON containing the information about:
+
+* HTTP request:
+  * Host
+  * Request URI
+  * Remote IP
+  * HTTP headers
+  * HTTP proxy headers
+* host:
+  * Hostname
+  * How many times it was called
+  * Env variables if `YOSOY_SHOW_ENVS` is set to `true`, `yes`, `on`, or `1`
+  * Files' contents if `YOSOY_SHOW_FILES` is set to a comma-separated list of (valid) files
 
 See [Kubernetes example](#kubernetes-example) below.
 
-
 ## Docker image
 
 The docker image is available on docker hub:
@@ -36,116 +41,58 @@ It exposes HTTP service on port 80.
 
 ## Kubernetes example
 
-Let's take a look at a sample Kubernetes deployment file. It uses both `YOSOY_SHOW_ENVS` and `YOSOY_SHOW_FILES`.
+There is a sample Kubernetes deployment file in the `test` folder. It uses both `YOSOY_SHOW_ENVS` and `YOSOY_SHOW_FILES`. The deployment uses Kubernetes Downward API to expose labels and annotations as volume files which are then returned by yosoy.
 
-> To illustrate `YOSOY_SHOW_FILES` functionality Kubernetes Downward API is used to expose labels and annotations as volume files which are then returned by yosoy.
+Deploy it to minikube and execute curl to the service a couple of times:
 
-```
-apiVersion: apps/v1
-kind: Deployment
-metadata:
-  name: camarero
-  labels:
-    app.kubernetes.io/name: camarero
-spec:
-  replicas: 2
-  selector:
-    matchLabels:
-      app.kubernetes.io/name: camarero
-  template:
-    metadata:
-      labels:
-        app.kubernetes.io/name: camarero
-    spec:
-      containers:
-      - name: yosoy
-        image: lukasz/yosoy
-        env:
-          - name: YOSOY_SHOW_ENVS
-            value: "true"
-          - name: YOSOY_SHOW_FILES
-            value: "/etc/podinfo/labels,/etc/podinfo/annotations"
-        ports:
-        - containerPort: 80
-        volumeMounts:
-        - name: podinfo
-          mountPath: /etc/podinfo
-      volumes:
-        - name: podinfo
-          downwardAPI:
-            items:
-              - path: "labels"
-                fieldRef:
-                  fieldPath: metadata.labels
-              - path: "annotations"
-                fieldRef:
-                  fieldPath: metadata.annotations
----
-apiVersion: v1
-kind: Service
-metadata:
-  name: camarero
-  labels:
-    app.kubernetes.io/name: camarero
-spec:
-  type: NodePort
-  selector:
-    app.kubernetes.io/name: camarero
-  ports:
-    - protocol: TCP
-      port: 80
-```
-
-Deploy above service (with 2 replicas) and execute curl to the service a couple of times:
-
-```
-kubectl apply -f test-deployment.yaml
-export NODE_PORT=$(kubectl get services/camarero -o go-template='{{(index .spec.ports 0).nodePort}}')
-curl $(minikube ip):$NODE_PORT
-curl $(minikube ip):$NODE_PORT
-curl $(minikube ip):$NODE_PORT
-curl $(minikube ip):$NODE_PORT
+```bash
+# start minikube
+minikube start
+# deploy test service
+kubectl apply -f test/deployment.yaml
+# tunnel to it and copy the URL as $URL variable
+minikube service --url camarero
+# simulate some HTTP requests
+curl -H "Host: gateway.myapp.com" $URL/camarero/abc
+curl -H "Host: gateway.myapp.com" $URL/camarero/abc
+curl -H "Host: gateway.myapp.com" $URL/camarero/abc
+curl -H "Host: gateway.myapp.com" $URL/camarero/abc
 ```
 
 A sample response looks like this:
 
-```
-Request URI: /
-Hostname: camarero-859d7c6d6b-kb5s5
-Remote IP: 172.18.0.1
-Called: 2
-
-HTTP headers:
-Accept: */*
-User-Agent: curl/7.64.1
-
-Env variables:
-PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
-HOSTNAME=camarero-859d7c6d6b-kb5s5
-YOSOY_SHOW_ENVS=true
-YOSOY_SHOW_FILES=/etc/podinfo/labels,/etc/podinfo/annotations
-CAMARERO_PORT_80_TCP_PORT=80
-CAMARERO_PORT_80_TCP_ADDR=10.105.203.131
-KUBERNETES_PORT=tcp://10.96.0.1:443
-KUBERNETES_PORT_443_TCP_PORT=443
-CAMARERO_SERVICE_HOST=10.105.203.131
-KUBERNETES_PORT_443_TCP_PROTO=tcp
-KUBERNETES_SERVICE_HOST=10.96.0.1
-KUBERNETES_SERVICE_PORT=443
-KUBERNETES_SERVICE_PORT_HTTPS=443
-KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443
-KUBERNETES_PORT_443_TCP_ADDR=10.96.0.1
-CAMARERO_PORT=tcp://10.105.203.131:80
-CAMARERO_SERVICE_PORT=80
-CAMARERO_PORT_80_TCP=tcp://10.105.203.131:80
-CAMARERO_PORT_80_TCP_PROTO=tcp
-HOME=/root
-
-File /etc/podinfo/labels:
-app.kubernetes.io/name="camarero"
-pod-template-hash="859d7c6d6b"
-
-File /etc/podinfo/annotations:
-kubernetes.io/config.seen="2020-11-17T07:38:15.374049163Z"
-kubernetes.io/config.source="api"
+```json
+{
+  "host": "gateway.myapp.com",
+  "requestUri": "/camarero/abc",
+  "remoteAddr": "172.17.0.1",
+  "counter": 4,
+  "headers": {
+    "Accept": [
+      "*/*"
+    ],
+    "User-Agent": [
+      "curl/7.64.1"
+    ]
+  },
+  "hostname": "camarero-77787464ff-hjdkq",
+  "envVariables": [
+    "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
+    "HOSTNAME=camarero-77787464ff-hjdkq",
+    "YOSOY_SHOW_ENVS=true",
+    "YOSOY_SHOW_FILES=/etc/podinfo/labels,/etc/podinfo/annotations",
+    "CAMARERO_SERVICE_HOST=10.97.113.33",
+    "CAMARERO_PORT=tcp://10.97.113.33:80",
+    "CAMARERO_PORT_80_TCP=tcp://10.97.113.33:80",
+    "CAMARERO_PORT_80_TCP_ADDR=10.97.113.33",
+    "CAMARERO_SERVICE_PORT=80",
+    "CAMARERO_PORT_80_TCP_PROTO=tcp",
+    "CAMARERO_PORT_80_TCP_PORT=80",
+    "HOME=/root"
+  ],
+  "files": {
+    "/etc/podinfo/annotations": "kubernetes.io/config.seen=\"2021-02-03T13:18:34.563751030Z\"\nkubernetes.io/config.source=\"api\"",
+    "/etc/podinfo/labels": "app.kubernetes.io/name=\"camarero\"\npod-template-hash=\"77787464ff\""
+  }
+}
 ```

go.mod

@@ -0,0 +1,9 @@
+module github.com/lukaszbudnik/yosoy
+
+go 1.15
+
+require (
+	github.com/gorilla/handlers v1.5.1
+	github.com/gorilla/mux v1.8.0
+	github.com/stretchr/testify v1.7.0
+)

go.sum

@@ -0,0 +1,16 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/felixge/httpsnoop v1.0.1 h1:lvB5Jl89CsZtGIWuTcDM1E/vkVs49/Ml7JJe07l8SPQ=
+github.com/felixge/httpsnoop v1.0.1/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
+github.com/gorilla/handlers v1.5.1 h1:9lRY6j8DEeeBT10CvO9hGW0gmky0BprnvDI5vfhUHH4=
+github.com/gorilla/handlers v1.5.1/go.mod h1:t8XrUpc4KVXb7HGyJ4/cEnwQiaxrX/hz1Zv/4g96P1Q=
+github.com/gorilla/mux v1.8.0 h1:i40aqfkR1h2SlN9hojwV5ZA91wcXFOvkdNIeFDP5koI=
+github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

server.go

@@ -1,76 +1,103 @@
 package main
 
 import (
-	"fmt"
+	"encoding/json"
 	"io/ioutil"
+	"log"
 	"net/http"
 	"os"
-	"sort"
 	"strings"
-	"time"
+
+	"github.com/gorilla/handlers"
+	"github.com/gorilla/mux"
 )
 
+type response struct {
+	Host         string              `json:"host"`
+	RequestURI   string              `json:"requestUri"`
+	RemoteAddr   string              `json:"remoteAddr"`
+	Counter      int                 `json:"counter"`
+	Headers      map[string][]string `json:"headers"`
+	Hostname     string              `json:"hostname"`
+	EnvVariables []string            `json:"envVariables,omitempty"`
+	Files        map[string]string   `json:"files,omitempty"`
+}
+
 var counter = 0
 var hostname = os.Getenv("HOSTNAME")
-var showEnvs = os.Getenv("YOSOY_SHOW_ENVS")
-var showFiles = os.Getenv("YOSOY_SHOW_FILES")
+
+func preflight(w http.ResponseWriter, req *http.Request) {
+	w.Header().Set("Access-Control-Allow-Origin", "*")
+	w.Header().Set("Access-Control-Allow-Methods", "*")
+	w.Header().Set("Access-Control-Allow-Headers", "*")
+	w.Header().Set("Access-Control-Allow-Credentials", "true")
+	w.Header().Set("Access-Control-Expose-Headers", "*")
+	w.Header().Set("Access-Control-Max-Age", "600")
+	w.WriteHeader(http.StatusOK)
+}
 
 func handler(w http.ResponseWriter, req *http.Request) {
-	if req.RequestURI == "/favicon.ico" {
-		w.WriteHeader(http.StatusNotFound)
-		return
-	}
+	w.Header().Set("Access-Control-Allow-Origin", "*")
+
+	showEnvs := os.Getenv("YOSOY_SHOW_ENVS")
+	showFiles := os.Getenv("YOSOY_SHOW_FILES")
+
+	response := &response{}
 
-	remoteAddr := req.RemoteAddr
-	if index := strings.LastIndex(remoteAddr, ":"); index > 0 {
-		remoteAddr = remoteAddr[0:index]
-	}
-	fmt.Printf("[%v] - %v - %v - \"%v %v\"\n", hostname, time.Now().Format(time.RFC3339), remoteAddr, req.Method, req.RequestURI)
-	w.WriteHeader(http.StatusOK)
-	w.Header().Add("Content-Type", "text/plain")
-	fmt.Fprintf(w, "Request URI: %v\n", req.RequestURI)
-	fmt.Fprintf(w, "Hostname: %v\n", hostname)
-	fmt.Fprintf(w, "Remote IP: %v\n", remoteAddr)
 	counter++
-	fmt.Fprintf(w, "Called: %v\n", counter)
-	fmt.Fprintln(w)
-	fmt.Fprintf(w, "HTTP headers:\n")
-	headers := make([]string, 0, len(req.Header))
-	for k := range req.Header {
-		headers = append(headers, k)
-	}
-	sort.Strings(headers)
-	for _, header := range headers {
-		headers := req.Header[header]
-		for _, h := range headers {
-			fmt.Fprintf(w, "%v: %v\n", header, h)
-		}
-	}
+	response.Counter = counter
+
+	remoteAddr := remoteAddrWithoutPort(req)
+	response.RemoteAddr = remoteAddr
+
+	response.RequestURI = req.RequestURI
+	response.Host = req.Host
+	response.Headers = req.Header
+
+	response.Hostname = hostname
+
 	if strings.ToLower(showEnvs) == "true" || strings.ToLower(showEnvs) == "yes" || strings.ToLower(showEnvs) == "on" || showEnvs == "1" {
-		fmt.Fprintln(w)
-		fmt.Fprintf(w, "Env variables:\n")
-		for _, e := range os.Environ() {
-			fmt.Fprintln(w, e)
-		}
+		response.EnvVariables = os.Environ()
 	}
 	if len(showFiles) > 0 {
+		response.Files = make(map[string]string)
 		files := strings.Split(showFiles, ",")
 		for _, file := range files {
 			bytes, err := ioutil.ReadFile(file)
 			if err != nil {
-				fmt.Printf("[%v] - %v - could not read file %v: %v\n", hostname, time.Now().Format(time.RFC3339), file, err)
+				log.Printf("Could not read file %v: %v\n", file, err)
 				continue
 			}
-			fmt.Fprintln(w)
-			fmt.Fprintf(w, "File %v:\n", file)
 			contents := string(bytes)
-			fmt.Fprintln(w, contents)
+			response.Files[file] = contents
 		}
 	}
+
+	w.Header().Add("Content-Type", "application/json; charset=utf-8")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(response)
+}
+
+func remoteAddrWithoutPort(req *http.Request) string {
+	remoteAddr := req.RemoteAddr
+	if index := strings.LastIndex(remoteAddr, ":"); index > 0 {
+		remoteAddr = remoteAddr[0:index]
+	}
+	return remoteAddr
 }
 
 func main() {
-	fmt.Printf("[%v] - %v - yosoy is up!\n", hostname, time.Now().Format(time.RFC3339))
-	http.HandleFunc("/", handler)
-	http.ListenAndServe(":80", nil)
+	log.Printf("yosoy is up %v\n", hostname)
+
+	r := mux.NewRouter()
+
+	r.Handle("/favicon.ico", r.NotFoundHandler)
+	r.PathPrefix("/").HandlerFunc(preflight).Methods(http.MethodOptions)
+	r.PathPrefix("/").HandlerFunc(handler).Methods(http.MethodGet, http.MethodPut, http.MethodPatch, http.MethodPost, http.MethodDelete, http.MethodConnect, http.MethodHead, http.MethodTrace)
+
+	loggingRouter := handlers.CombinedLoggingHandler(os.Stdout, r)
+	proxyRouter := handlers.ProxyHeaders(loggingRouter)
+	recoveryRouter := handlers.RecoveryHandler()(proxyRouter)
+
+	http.ListenAndServe(":80", recoveryRouter)
 }

server_test.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestHandler(t *testing.T) {
+	os.Setenv("YOSOY_SHOW_ENVS", "true")
+	os.Setenv("YOSOY_SHOW_FILES", ".gitignore")
+
+	req, err := http.NewRequest("GET", "https://example.org/sample/path", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	req.Header.Set("Accept", "*/*")
+
+	rr := httptest.NewRecorder()
+	handler := http.HandlerFunc(handler)
+
+	handler.ServeHTTP(rr, req)
+
+	if status := rr.Code; status != http.StatusOK {
+		t.Errorf("handler returned wrong status code: got %v want %v", status, http.StatusOK)
+	}
+
+	var response response
+	json.Unmarshal(rr.Body.Bytes(), &response)
+
+	// test response
+	assert.Equal(t, 1, response.Counter)
+	assert.Equal(t, "example.org", response.Host)
+	assert.NotEmpty(t, response.EnvVariables)
+	assert.NotEmpty(t, response.Files[".gitignore"])
+
+	// test cors
+	assert.Contains(t, rr.HeaderMap["Access-Control-Allow-Origin"], "*")
+}

test/deployment.yaml

@@ -0,0 +1,53 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: camarero
+  labels:
+    app.kubernetes.io/name: camarero
+spec:
+  replicas: 2
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: camarero
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/name: camarero
+    spec:
+      containers:
+      - name: yosoy
+        image: lukasz/yosoy
+        env:
+          - name: YOSOY_SHOW_ENVS
+            value: "true"
+          - name: YOSOY_SHOW_FILES
+            value: "/etc/podinfo/labels,/etc/podinfo/annotations"
+        ports:
+        - containerPort: 80
+        volumeMounts:
+        - name: podinfo
+          mountPath: /etc/podinfo
+      volumes:
+        - name: podinfo
+          downwardAPI:
+            items:
+              - path: "labels"
+                fieldRef:
+                  fieldPath: metadata.labels
+              - path: "annotations"
+                fieldRef:
+                  fieldPath: metadata.annotations
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: camarero
+  labels:
+    app.kubernetes.io/name: camarero
+spec:
+  type: NodePort
+  selector:
+    app.kubernetes.io/name: camarero
+  ports:
+    - protocol: TCP
+      port: 80