outpost: add lightweight, anonymous metrics

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

internal/outpost/ak/analytics.go

@@ -0,0 +1,80 @@
+package ak
+
+import (
+	"bytes"
+	"crypto/sha512"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"os"
+
+	log "github.com/sirupsen/logrus"
+	"goauthentik.io/internal/constants"
+)
+
+func exists(name string) bool {
+	_, err := os.Stat(name)
+	if err == nil {
+		return true
+	}
+	if errors.Is(err, os.ErrNotExist) {
+		return false
+	}
+	return false
+}
+
+func getEnv() string {
+	if _, o := os.LookupEnv("KUBERNETES_SERVICE_HOST"); o {
+		return "kubernetes"
+	}
+	if _, o := os.LookupEnv("CI"); o {
+		return "ci"
+	}
+	if exists("/tmp/authentik-mode") {
+		return "embedded"
+	}
+	return "custom"
+}
+
+func analytics(akURL url.URL, on string) {
+	if _, s := os.LookupEnv("AUTHENTIK_DISABLE_ANALYTICS"); s {
+		return
+	}
+	body := struct {
+		Domain   string `json:"domain"`
+		Name     string `json:"name"`
+		URL      string `json:"url"`
+		Referrer string `json:"referrer"`
+	}{
+		Domain:   "authentik",
+		Name:     "pageview",
+		URL:      fmt.Sprintf("http://localhost/outpost/%s", getEnv()),
+		Referrer: fmt.Sprintf("%s (%s)", constants.VERSION, constants.BUILD()),
+	}
+	b, err := json.Marshal(body)
+	if err != nil {
+		log.WithError(err).Debug("test")
+	}
+	ua := fmt.Sprintf("%s-%s", akURL.Host, on)
+	h := sha512.New()
+	h.Write([]byte(ua))
+
+	req, err := http.NewRequest("POST", "https://goauthentik.io/api/event", bytes.NewReader(b))
+	if err != nil {
+		log.WithError(err).Debug("test")
+	}
+	req.Header.Set("Content-Type", "text/plain")
+	req.Header.Set("User-Agent", hex.EncodeToString(h.Sum(nil)))
+	r, err := http.DefaultClient.Do(req)
+	if err != nil {
+		log.WithError(err).Debug("test")
+	}
+	if r.StatusCode >= 400 {
+		b, _ := ioutil.ReadAll(r.Body)
+		log.WithField("status", r.StatusCode).WithField("body", string(b)).Debug("failed")
+	}
+}

internal/outpost/ak/api.go

@@ -67,6 +67,7 @@ func NewAPIController(akURL url.URL, token string) *APIController {
 	}
 	outpost := outposts.Results[0]
 	doGlobalSetup(outpost.Config)
+	go analytics(akURL, outpost.Name)
 
 	log.WithField("name", outpost.Name).Debug("Fetched outpost configuration")