332 lines
9.2 KiB
Go
332 lines
9.2 KiB
Go
package main
|
|
|
|
import (
|
|
"encoding/json"
|
|
"flag"
|
|
"html/template"
|
|
"io/ioutil"
|
|
"log"
|
|
"math/rand"
|
|
"net"
|
|
"net/http"
|
|
"net/url"
|
|
"os"
|
|
"regexp"
|
|
"strconv"
|
|
"strings"
|
|
"time"
|
|
|
|
"github.com/asaskevich/govalidator"
|
|
"github.com/gorilla/handlers"
|
|
"github.com/gorilla/mux"
|
|
"github.com/patrickmn/go-cache"
|
|
)
|
|
|
|
type config struct {
|
|
addr string
|
|
domain string
|
|
dumpFile string
|
|
path string
|
|
proto string
|
|
hostSuf string
|
|
listenAddr string
|
|
port int
|
|
urlSize int
|
|
version bool
|
|
templates *template.Template
|
|
}
|
|
|
|
type body struct {
|
|
FullHeader bool
|
|
IsGhost bool
|
|
HasForm bool
|
|
IsLink bool
|
|
H1 string
|
|
H3 string
|
|
Line1 string
|
|
Line2 string
|
|
}
|
|
|
|
const (
|
|
letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789" // Base strings for randStringBytesMaskImprSrc
|
|
letterIdxBits = 6 // 6 bits to represent a letter index
|
|
letterIdxMask = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits
|
|
letterIdxMax = 63 / letterIdxBits // # of letter indices fitting in 63 bits
|
|
appVersion = "1.2.1"
|
|
)
|
|
|
|
var (
|
|
cfg config
|
|
src = rand.NewSource(time.Now().UnixNano())
|
|
pool = cache.New(240*time.Hour, 1*time.Hour)
|
|
)
|
|
|
|
func init() {
|
|
flag.StringVar(&cfg.addr, "addr", "localhost", "Address to listen for connections")
|
|
flag.StringVar(&cfg.domain, "domain", "localhost", "Domain to write to the URLs")
|
|
flag.StringVar(&cfg.dumpFile, "dump", "urls.json", "Path to the file to dump the kv db")
|
|
flag.StringVar(&cfg.path, "path", "", "Path to the base URL (https://localhost/PATH/... remember to append a / at the end")
|
|
flag.StringVar(&cfg.proto, "proto", "https", "proto to the base URL (HTTPS://localhost/path/... no real https here just to set the url (for like a proxy offloading https")
|
|
flag.IntVar(&cfg.port, "port", 8080, "Port to listen for connections")
|
|
flag.IntVar(&cfg.urlSize, "urlsize", 10, "Define the size of the shortened String, default 10")
|
|
flag.BoolVar(&cfg.version, "v", false, "prints current version")
|
|
flag.Parse()
|
|
|
|
if cfg.version {
|
|
log.SetFlags(0)
|
|
log.Println(appVersion)
|
|
os.Exit(0)
|
|
}
|
|
|
|
if cfg.port > 65535 || cfg.port < 1 {
|
|
log.Fatalln("Invalid port number")
|
|
}
|
|
if cfg.path != "" && !strings.HasSuffix(cfg.path, "/") {
|
|
cfg.path = cfg.path + "/"
|
|
}
|
|
|
|
if cfg.port != 80 && cfg.proto == "http" {
|
|
cfg.hostSuf = ":" + strconv.Itoa(cfg.port) + "/"
|
|
} else if cfg.port != 443 && cfg.proto == "https" {
|
|
cfg.hostSuf = ":" + strconv.Itoa(cfg.port) + "/"
|
|
} else if cfg.port == 443 || cfg.port == 80 {
|
|
cfg.hostSuf = "/"
|
|
}
|
|
|
|
ip := net.ParseIP(cfg.addr)
|
|
if ip != nil {
|
|
cfg.listenAddr = ip.String() + ":" + strconv.Itoa(cfg.port)
|
|
} else {
|
|
if govalidator.IsDNSName(cfg.addr) {
|
|
cfg.listenAddr = cfg.addr + ":" + strconv.Itoa(cfg.port)
|
|
} else {
|
|
log.Fatalln("Invalid ip address")
|
|
}
|
|
}
|
|
|
|
if !govalidator.IsDNSName(cfg.domain) {
|
|
log.Fatalln("Invalid domain address")
|
|
}
|
|
|
|
cfg.templates = template.Must(template.ParseFiles("templates/response.html"))
|
|
}
|
|
|
|
func (c config) index(w http.ResponseWriter, r *http.Request) {
|
|
b := body{
|
|
HasForm: true,
|
|
Line1: "Welcome to Short, the simple URL shortener,",
|
|
Line2: "Type an URL below to shorten it",
|
|
}
|
|
c.templates.Execute(w, b)
|
|
}
|
|
|
|
// get executes the GET command
|
|
func get(key string) (string, bool) {
|
|
value, status := pool.Get(key)
|
|
if !status {
|
|
return "", status
|
|
}
|
|
return value.(string), status
|
|
}
|
|
|
|
// set executes the redis SET command
|
|
func set(key, suffix string) {
|
|
pool.Set(suffix, key, 0)
|
|
}
|
|
|
|
// redirect reads the key from the requests url (GET /key) searches the
|
|
// kv database for it and if found redirects the user to value, if not
|
|
// found return a 404.
|
|
func (c config) redirect(w http.ResponseWriter, r *http.Request) {
|
|
vals := mux.Vars(r)
|
|
key := vals["key"]
|
|
b := body{
|
|
FullHeader: true,
|
|
IsGhost: true,
|
|
HasForm: true,
|
|
H1: "404",
|
|
H3: "page not found",
|
|
Line1: "Boo, looks like this ghost stole this page!",
|
|
Line2: "But you can type an URL below to shorten it",
|
|
}
|
|
if c.path != "" {
|
|
key = strings.Replace(key, c.path, "", 1)
|
|
}
|
|
rgx, _ := regexp.Compile("[a-zA-Z0-9]+")
|
|
key = rgx.FindString(key)
|
|
key, status := get(key)
|
|
if !status {
|
|
w.WriteHeader(http.StatusNotFound)
|
|
c.templates.Execute(w, b)
|
|
return
|
|
}
|
|
u, _ := url.Parse(key)
|
|
if u.Scheme == "" {
|
|
u.Scheme = "https"
|
|
}
|
|
http.Redirect(w, r, u.String(), http.StatusFound)
|
|
}
|
|
|
|
// shortner reads url from a POST request, validates the url, generate a
|
|
// random suffix string of urlSize size, checks if the suffix string is
|
|
// unique on the kv database and if not unique regenerates it and checks again,
|
|
// then if writes the kv pair suffix, url to the database and return the
|
|
// shortened url to the user
|
|
func (c config) shortner(w http.ResponseWriter, r *http.Request) {
|
|
if !govalidator.IsURL(r.FormValue("url")) {
|
|
b := body{
|
|
FullHeader: true,
|
|
IsGhost: true,
|
|
HasForm: true,
|
|
H1: "400",
|
|
H3: "bad request",
|
|
Line1: "Boo, looks like this ghost stole this page!",
|
|
Line2: "But you can type an URL below to shorten it",
|
|
}
|
|
w.WriteHeader(http.StatusBadRequest)
|
|
c.templates.Execute(w, b)
|
|
return
|
|
}
|
|
u, _ := url.Parse(r.FormValue("url"))
|
|
suffix := randStringBytesMaskImprSrc(c.urlSize)
|
|
|
|
for {
|
|
_, status := get(suffix)
|
|
if !status {
|
|
break
|
|
}
|
|
suffix = randStringBytesMaskImprSrc(c.urlSize)
|
|
}
|
|
set(u.String(), suffix)
|
|
shortend := c.proto + "://" + c.domain + c.hostSuf + c.path + suffix
|
|
b := body{
|
|
IsLink: true,
|
|
Line1: shortend,
|
|
}
|
|
c.templates.Execute(w, b)
|
|
}
|
|
|
|
// randStringBytesMaskImprSrc Generate random string of n size
|
|
func randStringBytesMaskImprSrc(n int) string {
|
|
b := make([]byte, n)
|
|
// A src.Int63() generates 63 random bits, enough for letterIdxMax characters!
|
|
for i, cache, remain := n-1, src.Int63(), letterIdxMax; i >= 0; {
|
|
if remain == 0 {
|
|
cache, remain = src.Int63(), letterIdxMax
|
|
}
|
|
if idx := int(cache & letterIdxMask); idx < len(letterBytes) {
|
|
b[i] = letterBytes[idx]
|
|
i--
|
|
}
|
|
cache >>= letterIdxBits
|
|
remain--
|
|
}
|
|
return string(b)
|
|
}
|
|
|
|
// internalError receives a http.ResponseWriter, msg and error and
|
|
// return a internal error page with http code 500 to the user
|
|
func (c config) internalError(w http.ResponseWriter, msg string, err error) {
|
|
b := body{
|
|
FullHeader: true,
|
|
IsGhost: true,
|
|
HasForm: true,
|
|
H1: "500",
|
|
H3: "internal erver error",
|
|
Line1: "Boo, the ghost is broken :(",
|
|
Line2: "His last words where: " + err.Error(),
|
|
}
|
|
log.Println(err)
|
|
w.WriteHeader(http.StatusInternalServerError)
|
|
c.templates.Execute(w, b)
|
|
}
|
|
|
|
// itemsCount returns the number of kv pairs on the in meomry database
|
|
func (c config) itemsCount(w http.ResponseWriter, r *http.Request) {
|
|
w.Write(
|
|
[]byte(
|
|
strconv.Itoa(
|
|
pool.ItemCount(),
|
|
),
|
|
),
|
|
)
|
|
}
|
|
|
|
// itemsDump returns a json with all the kv pairs on the in memory database
|
|
func (c config) itemsDump(w http.ResponseWriter, r *http.Request) {
|
|
dumpObj, err := json.Marshal(
|
|
pool.Items(),
|
|
)
|
|
if err != nil {
|
|
c.internalError(w, "Unable to dump key value db: ", err)
|
|
}
|
|
w.Write(
|
|
[]byte(dumpObj),
|
|
)
|
|
}
|
|
|
|
// itemsFromFile loads kv pairs from the dumpFile json to the in memory database
|
|
func (c config) itemsFromFile(w http.ResponseWriter, r *http.Request) {
|
|
jsonFile, err := ioutil.ReadFile(c.dumpFile)
|
|
var dumpObj map[string]cache.Item
|
|
json.Unmarshal([]byte(jsonFile), &dumpObj)
|
|
if err != nil {
|
|
c.internalError(w, "Cannot open file "+c.dumpFile+": ", err)
|
|
return
|
|
}
|
|
pool = cache.NewFrom(240*time.Hour, 1*time.Hour, dumpObj)
|
|
b := body{
|
|
Line1: "Imported " + strconv.Itoa(len(dumpObj)) + " items to the DB",
|
|
}
|
|
c.templates.Execute(w, b)
|
|
}
|
|
|
|
// itemsFromPost loads kv pairs from a json POST to the in memory database
|
|
func (c config) itemsFromPost(w http.ResponseWriter, r *http.Request) {
|
|
decoder := json.NewDecoder(r.Body)
|
|
var dumpObj map[string]cache.Item
|
|
err := decoder.Decode(&dumpObj)
|
|
if err != nil {
|
|
c.internalError(w, "Cannot parse JSON: ", err)
|
|
return
|
|
}
|
|
pool = cache.NewFrom(240*time.Hour, 1*time.Hour, dumpObj)
|
|
b := body{
|
|
Line1: "Imported " + strconv.Itoa(len(dumpObj)) + " items to the DB",
|
|
}
|
|
c.templates.Execute(w, b)
|
|
}
|
|
|
|
// itemsDumpToFile dumps the kv pairs from the in memory database to the dumpFile
|
|
func (c config) itemsDumpToFile(w http.ResponseWriter, r *http.Request) {
|
|
dumpObj, _ := json.Marshal(
|
|
pool.Items(),
|
|
)
|
|
err := ioutil.WriteFile(c.dumpFile, dumpObj, 0644)
|
|
if err != nil {
|
|
c.internalError(w, "Failed to open json file: ", err)
|
|
return
|
|
}
|
|
b := body{
|
|
Line1: "Imported " + "Dump writen to: " + c.dumpFile,
|
|
}
|
|
c.templates.Execute(w, b)
|
|
}
|
|
|
|
func main() {
|
|
|
|
r := mux.NewRouter()
|
|
|
|
r.HandleFunc("/", cfg.index).Methods("GET")
|
|
r.HandleFunc("/", cfg.shortner).Methods("POST")
|
|
r.HandleFunc("/{key}", cfg.redirect).Methods("GET")
|
|
r.HandleFunc("/v1/dumpToFile", cfg.itemsDumpToFile).Methods("GET")
|
|
r.HandleFunc("/v1/fromFile", cfg.itemsFromFile).Methods("GET")
|
|
r.HandleFunc("/v1/count", cfg.itemsCount).Methods("GET")
|
|
r.HandleFunc("/v1/dump", cfg.itemsDump).Methods("GET")
|
|
r.HandleFunc("/v1/fromPost", cfg.itemsFromPost).Methods("POST")
|
|
|
|
log.Printf("Domain: %s, URL Proto: %s, Listen Address: %s\n", cfg.domain, cfg.proto, cfg.listenAddr)
|
|
log.Fatal(http.ListenAndServe(cfg.listenAddr, handlers.CombinedLoggingHandler(os.Stdout, r)))
|
|
}
|