first version, prints request URI, time, counts requests, can show env variables, and files

Docker

@@ -0,0 +1,16 @@
+FROM golang:1.13.5-alpine3.10 as builder
+
+MAINTAINER Łukasz Budnik lukasz.budnik@gmail.com
+
+# build yosoy
+RUN apk add git
+RUN git clone https://github.com/lukaszbudnik/yosoy.git
+RUN cd /go/yosoy && go build
+
+FROM alpine:3.10
+COPY --from=builder /go/yosoy/yosoy /bin
+
+# register entrypoint
+ENTRYPOINT ["yosoy"]
+
+EXPOSE 80

server.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"strings"
+	"time"
+)
+
+var counter = 0
+var hostname = os.Getenv("HOSTNAME")
+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)
+	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)
+	counter++
+	fmt.Fprintf(w, "Called: %v\n", counter)
+	fmt.Fprintln(w)
+	fmt.Fprintf(w, "HTTP headers:\n")
+	for name, headers := range req.Header {
+		for _, h := range headers {
+			fmt.Fprintf(w, "%v: %v\n", name, h)
+		}
+	}
+	if showEnvs == "1" || strings.ToLower(showEnvs) == "yes" || strings.ToLower(showEnvs) == "true" {
+		fmt.Fprintln(w)
+		fmt.Fprintf(w, "Env variables:\n")
+		for _, e := range os.Environ() {
+			fmt.Fprintln(w, e)
+		}
+	}
+	if len(showFiles) > 0 {
+		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)
+				continue
+			}
+			fmt.Fprintln(w)
+			fmt.Fprintf(w, "File %v:\n", file)
+			contents := string(bytes)
+			fmt.Fprintln(w, contents)
+		}
+	}
+}
+
+func main() {
+	fmt.Printf("[%v] - %v - YoSoy is up!\n", hostname, time.Now().Format(time.RFC3339))
+	http.HandleFunc("/", handler)
+	http.ListenAndServe(":80", nil)
+}