minor changes in code, added better description and Kubernetes example

README.md

@@ -1,2 +1,117 @@
 # yosoy
-Yo soy is a tool for stubbing distributed applications.
+
+yosoy is a HTTP service for stubbing 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".
+
+yosoy is extremely useful when creating a distributed application stub and you need to see a more meaningful responses than a default nginx welcome page.
+
+yosoy will provide information like (see example below):
+
+* 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
+
+## Docker image
+
+The docker image is available on docker hub:
+
+```
+lukasz/yosoy
+```
+
+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`. To illustrate `YOSOY_SHOW_FILES` functionality it uses Kubernetes Downward API to expose labels and annotations as volume files which are then read by yosoy.
+
+```
+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
+```
+
+Execute curl a couple of times and you should see:
+
+```
+Request URI: /
+Hostname: camarero-7fd97dc5f5-545mt
+Remote IP: 172.18.0.1
+Called: 4
+
+HTTP headers:
+User-Agent: curl/7.58.0
+Accept: */*
+
+Env variables:
+PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
+HOSTNAME=camarero-7fd97dc5f5-545mt
+YOSOY_SHOW_ENVS=true
+YOSOY_SHOW_FILES=/etc/podinfo/labels,/etc/podinfo/annotations
+KUBERNETES_PORT=tcp://10.96.0.1:443
+KUBERNETES_PORT_443_TCP_PROTO=tcp
+CAMARERO_SERVICE_HOST=10.96.183.207
+KUBERNETES_SERVICE_HOST=10.96.0.1
+KUBERNETES_SERVICE_PORT=443
+KUBERNETES_SERVICE_PORT_HTTPS=443
+CAMARERO_SERVICE_PORT=80
+CAMARERO_PORT_80_TCP_PROTO=tcp
+KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443
+CAMARERO_PORT_80_TCP=tcp://10.96.183.207:80
+CAMARERO_PORT_80_TCP_PORT=80
+KUBERNETES_PORT_443_TCP_PORT=443
+KUBERNETES_PORT_443_TCP_ADDR=10.96.0.1
+CAMARERO_PORT=tcp://10.96.183.207:80
+CAMARERO_PORT_80_TCP_ADDR=10.96.183.207
+HOME=/root
+
+File /etc/podinfo/labels:
+app.kubernetes.io/component="api"
+app.kubernetes.io/name="camarero"
+app.kubernetes.io/part-of="camarero"
+app.kubernetes.io/version="0.0.1"
+pod-template-hash="7fd97dc5f5"
+
+File /etc/podinfo/annotations:
+kubernetes.io/config.seen="2020-11-13T14:36:17.234235115Z"
+kubernetes.io/config.source="api"
+```

server.go

@@ -15,12 +15,17 @@ var showEnvs = os.Getenv("YOSOY_SHOW_ENVS")
 var showFiles = os.Getenv("YOSOY_SHOW_FILES")
 
 func handler(w http.ResponseWriter, req *http.Request) {
-	fmt.Printf("[%v] - %v - %v - \"%v %v\"\n", hostname, time.Now().Format(time.RFC3339), req.RemoteAddr, req.Method, req.RequestURI)
+	remoteAddr := req.RemoteAddr
+	// LastIndex works better with IPv6
+	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(200)
 	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", req.RemoteAddr)
+	fmt.Fprintf(w, "Remote IP: %v\n", remoteAddr)
 	counter++
 	fmt.Fprintf(w, "Called: %v\n", counter)
 	fmt.Fprintln(w)
@@ -30,7 +35,7 @@ func handler(w http.ResponseWriter, req *http.Request) {
 			fmt.Fprintf(w, "%v: %v\n", name, h)
 		}
 	}
-	if showEnvs == "1" || strings.ToLower(showEnvs) == "yes" || strings.ToLower(showEnvs) == "true" {
+	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() {
@@ -54,7 +59,7 @@ func handler(w http.ResponseWriter, req *http.Request) {
 }
 
 func main() {
-	fmt.Printf("[%v] - %v - YoSoy is up!\n", hostname, time.Now().Format(time.RFC3339))
+	fmt.Printf("[%v] - %v - yosoy is up!\n", hostname, time.Now().Format(time.RFC3339))
 	http.HandleFunc("/", handler)
 	http.ListenAndServe(":80", nil)
 }