124 lines
3.3 KiB
Go
124 lines
3.3 KiB
Go
package main
|
|
|
|
import (
|
|
"context"
|
|
"github.com/prometheus/client_golang/prometheus"
|
|
"github.com/prometheus/client_golang/prometheus/promauto"
|
|
"github.com/prometheus/client_golang/prometheus/promhttp"
|
|
"go.mongodb.org/mongo-driver/bson"
|
|
"go.mongodb.org/mongo-driver/bson/primitive"
|
|
"go.mongodb.org/mongo-driver/mongo"
|
|
"go.mongodb.org/mongo-driver/mongo/options"
|
|
"go.mongodb.org/mongo-driver/x/mongo/driver/connstring"
|
|
"log"
|
|
"net/http"
|
|
"os"
|
|
"regexp"
|
|
"strings"
|
|
"time"
|
|
)
|
|
|
|
type inventoryItemType struct {
|
|
ID primitive.ObjectID `bson:"_id" json:"_id,omitempty"`
|
|
Shortener struct {
|
|
Slug string `bson:"slug" json:"slug"`
|
|
URL string `bson:"url" json:"url"`
|
|
} `bson:"shortener" json:"shortener"`
|
|
}
|
|
|
|
var reValid = regexp.MustCompile("^[a-zA-Z0-9]{4,6}$")
|
|
var mongoURI string = "mongodb://127.0.0.1:27017/default?replicaSet=rs0"
|
|
var collectionName string = "inventory"
|
|
var redirectFound string = os.Getenv("GOREDIRECT_FOUND")
|
|
var redirectNotFound string = os.Getenv("GOREDIRECT_NOT_FOUND")
|
|
|
|
func wrapper(coll *mongo.Collection) func(w http.ResponseWriter, r *http.Request) {
|
|
return func(w http.ResponseWriter, r *http.Request) {
|
|
counterQueries.Inc()
|
|
slug := r.URL.Path[1:]
|
|
match := reValid.MatchString(slug)
|
|
if !match {
|
|
counterInvalidSlug.Inc()
|
|
http.Error(w, "Invalid slug", 400)
|
|
return
|
|
}
|
|
|
|
var doc inventoryItemType
|
|
err := coll.FindOne(context.TODO(), bson.M{"shortener.slug": slug}).Decode(&doc)
|
|
if err != nil {
|
|
counterNotFound.Inc()
|
|
if redirectNotFound == "" {
|
|
http.NotFound(w, r)
|
|
return
|
|
}
|
|
|
|
http.Redirect(w, r, strings.Replace(redirectNotFound, "%s", slug, 1), 302)
|
|
return
|
|
}
|
|
|
|
counterFound.Inc()
|
|
var u = doc.Shortener.URL
|
|
if u == "" {
|
|
u = strings.Replace(redirectFound, "%s", doc.ID.Hex(), 1)
|
|
}
|
|
http.Redirect(w, r, u, 302)
|
|
log.Printf("Redirecting %s to %s\n", slug, doc.Shortener.URL)
|
|
}
|
|
}
|
|
|
|
var (
|
|
counterQueries = promauto.NewCounter(prometheus.CounterOpts{
|
|
Name: "goredirect_queries",
|
|
Help: "The total number of queries.",
|
|
})
|
|
counterInvalidSlug = promauto.NewCounter(prometheus.CounterOpts{
|
|
Name: "goredirect_invalid_slug",
|
|
Help: "The total number of queries that did not match regex.",
|
|
})
|
|
counterNotFound = promauto.NewCounter(prometheus.CounterOpts{
|
|
Name: "goredirect_not_found",
|
|
Help: "The total number of queries with unknown slug.",
|
|
})
|
|
counterFound = promauto.NewCounter(prometheus.CounterOpts{
|
|
Name: "goredirect_found",
|
|
Help: "The total number of queries that resulted in successful redirect.",
|
|
})
|
|
)
|
|
|
|
func main() {
|
|
if val := os.Getenv("GOREDIRECT_REGEX"); val != "" {
|
|
reValid = regexp.MustCompile(val)
|
|
}
|
|
|
|
if val := os.Getenv("MONGO_URI"); val != "" {
|
|
mongoURI = val
|
|
}
|
|
|
|
if val := os.Getenv("GOREDIRECT_COLLECTION"); val != "" {
|
|
collectionName = val
|
|
}
|
|
|
|
cs, err := connstring.ParseAndValidate(mongoURI)
|
|
client, err := mongo.NewClient(options.Client().ApplyURI(mongoURI))
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
|
|
err = client.Connect(ctx)
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
cancel()
|
|
coll := client.Database(cs.Database).Collection(collectionName)
|
|
defer client.Disconnect(ctx)
|
|
http.Handle("/metrics", promhttp.Handler())
|
|
http.HandleFunc("/", wrapper(coll))
|
|
|
|
log.Printf("Starting HTTP server\n")
|
|
err2 := http.ListenAndServe(":8080", nil)
|
|
if err2 != nil {
|
|
log.Fatal("ListenAndServe: ", err2)
|
|
}
|
|
|
|
}
|