124 lines
3.3 KiB
Go
124 lines
3.3 KiB
Go
package main
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import (
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"context"
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"github.com/prometheus/client_golang/prometheus"
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"github.com/prometheus/client_golang/prometheus/promauto"
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"github.com/prometheus/client_golang/prometheus/promhttp"
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"go.mongodb.org/mongo-driver/bson"
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"go.mongodb.org/mongo-driver/bson/primitive"
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"go.mongodb.org/mongo-driver/mongo"
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"go.mongodb.org/mongo-driver/mongo/options"
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"go.mongodb.org/mongo-driver/x/mongo/driver/connstring"
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"log"
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"net/http"
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"os"
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"regexp"
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"strings"
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"time"
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)
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type inventoryItemType struct {
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ID primitive.ObjectID `bson:"_id" json:"_id,omitempty"`
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Shortener struct {
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Slug string `bson:"slug" json:"slug"`
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URL string `bson:"url" json:"url"`
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} `bson:"shortener" json:"shortener"`
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}
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var reValid = regexp.MustCompile("^[a-zA-Z0-9]{4,6}$")
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var mongoURI string = "mongodb://127.0.0.1:27017/default?replicaSet=rs0"
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var collectionName string = "inventory"
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var redirectFound string = os.Getenv("GOREDIRECT_FOUND")
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var redirectNotFound string = os.Getenv("GOREDIRECT_NOT_FOUND")
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func wrapper(coll *mongo.Collection) func(w http.ResponseWriter, r *http.Request) {
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return func(w http.ResponseWriter, r *http.Request) {
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counterQueries.Inc()
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slug := r.URL.Path[1:]
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match := reValid.MatchString(slug)
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if !match {
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counterInvalidSlug.Inc()
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http.Error(w, "Invalid slug", 400)
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return
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}
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var doc inventoryItemType
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err := coll.FindOne(context.TODO(), bson.M{"shortener.slug": slug}).Decode(&doc)
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if err != nil {
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counterNotFound.Inc()
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if redirectNotFound == "" {
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http.NotFound(w, r)
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return
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}
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http.Redirect(w, r, strings.Replace(redirectNotFound, "%s", slug, 1), 302)
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return
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}
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counterFound.Inc()
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var u = doc.Shortener.URL
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if u == "" {
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u = strings.Replace(redirectFound, "%s", doc.ID.Hex(), 1)
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}
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http.Redirect(w, r, u, 302)
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log.Printf("Redirecting %s to %s\n", slug, doc.Shortener.URL)
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}
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}
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var (
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counterQueries = promauto.NewCounter(prometheus.CounterOpts{
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Name: "goredirect_queries",
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Help: "The total number of queries.",
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})
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counterInvalidSlug = promauto.NewCounter(prometheus.CounterOpts{
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Name: "goredirect_invalid_slug",
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Help: "The total number of queries that did not match regex.",
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})
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counterNotFound = promauto.NewCounter(prometheus.CounterOpts{
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Name: "goredirect_not_found",
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Help: "The total number of queries with unknown slug.",
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})
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counterFound = promauto.NewCounter(prometheus.CounterOpts{
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Name: "goredirect_found",
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Help: "The total number of queries that resulted in successful redirect.",
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})
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)
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func main() {
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if val := os.Getenv("GOREDIRECT_REGEX"); val != "" {
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reValid = regexp.MustCompile(val)
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}
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if val := os.Getenv("MONGO_URI"); val != "" {
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mongoURI = val
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}
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if val := os.Getenv("GOREDIRECT_COLLECTION"); val != "" {
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collectionName = val
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}
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cs, err := connstring.ParseAndValidate(mongoURI)
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client, err := mongo.NewClient(options.Client().ApplyURI(mongoURI))
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if err != nil {
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log.Fatal(err)
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}
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ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
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err = client.Connect(ctx)
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if err != nil {
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log.Fatal(err)
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}
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cancel()
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coll := client.Database(cs.Database).Collection(collectionName)
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defer client.Disconnect(ctx)
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http.Handle("/metrics", promhttp.Handler())
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http.HandleFunc("/", wrapper(coll))
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log.Printf("Starting HTTP server\n")
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err2 := http.ListenAndServe(":80", nil)
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if err2 != nil {
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log.Fatal("ListenAndServe: ", err2)
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}
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}
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