安装Markdown解析库：https://github.com/russross/blackfriday

第一版：go get github.com/russross/blackfriday
第二版：go get -u gopkg.in/russross/blackfriday.v2

package main

import (
    "net/http"
    "fmt"
    "path/filepath"
    "strings"
    "io/ioutil"
    //"github.com/russross/blackfriday"
    "gopkg.in/russross/blackfriday.v2"
)

func handleRequest(w http.ResponseWriter, r *http.Request) {
    fp, _ := filepath.Abs("")
    fn := fp + r.URL.Path;
    fmt.Println(fn);
    if(!strings.HasSuffix(fn, ".md")){
        http.ServeFile(w, r, fn)
    }else{        
        fileread, _ := ioutil.ReadFile(fn)
        //fmt.Fprintln(w, string(blackfriday.MarkdownCommon([]byte(fileread))))
        fmt.Fprintln(w, string(blackfriday.Run([]byte(fileread))))
    }
}

func main() {
    http.HandleFunc("/", handleRequest)
    http.ListenAndServe(":8000", nil)
}

终端：go run md.go

浏览器：localhost:8000