From 6294c57704801ee350af28620c9b2e1775f7d443 Mon Sep 17 00:00:00 2001
From: kolaente <k@knt.li>
Date: Sat, 10 Oct 2020 13:17:20 +0200
Subject: [PATCH] Use keyvalue for metrics

---
 pkg/metrics/active_users.go      | 28 +++++-----------------------
 pkg/metrics/metrics.go           | 25 ++++++++++++-------------
 pkg/modules/keyvalue/keyvalue.go | 10 ++++++++++
 pkg/routes/metrics.go            |  4 ----
 4 files changed, 27 insertions(+), 40 deletions(-)

diff --git a/pkg/metrics/active_users.go b/pkg/metrics/active_users.go
index af3c72821..328be356d 100644
--- a/pkg/metrics/active_users.go
+++ b/pkg/metrics/active_users.go
@@ -17,10 +17,9 @@
 package metrics
 
 import (
-	"bytes"
 	"code.vikunja.io/api/pkg/log"
+	"code.vikunja.io/api/pkg/modules/keyvalue"
 	"code.vikunja.io/web"
-	"encoding/gob"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
 	"sync"
@@ -91,36 +90,19 @@ func SetUserActive(a web.Auth) (err error) {
 
 // getActiveUsers returns the active users from redis
 func getActiveUsers() (users activeUsersMap, err error) {
-
-	activeUsersR, err := r.Get(ActiveUsersKey).Bytes()
-	if err != nil {
-		if err.Error() == "redis: nil" {
-			return users, nil
-		}
-		return
-	}
-
-	var b bytes.Buffer
-	_, err = b.Write(activeUsersR)
+	u, err := keyvalue.Get(ActiveUsersKey)
 	if err != nil {
 		return nil, err
 	}
-	d := gob.NewDecoder(&b)
-	if err := d.Decode(&users); err != nil {
-		return nil, err
-	}
+
+	users = u.(activeUsersMap)
 	return
 }
 
 // PushActiveUsers pushed the content of the activeUsers map to redis
 func PushActiveUsers() (err error) {
-	var b bytes.Buffer
-	e := gob.NewEncoder(&b)
 	activeUsers.mutex.Lock()
 	defer activeUsers.mutex.Unlock()
-	if err := e.Encode(activeUsers.users); err != nil {
-		return err
-	}
 
-	return r.Set(ActiveUsersKey, b.Bytes(), 0).Err()
+	return keyvalue.Put(ActiveUsersKey, activeUsers.users)
 }
diff --git a/pkg/metrics/metrics.go b/pkg/metrics/metrics.go
index 715543ef8..0d1a953d9 100644
--- a/pkg/metrics/metrics.go
+++ b/pkg/metrics/metrics.go
@@ -19,14 +19,12 @@ package metrics
 import (
 	"code.vikunja.io/api/pkg/config"
 	"code.vikunja.io/api/pkg/log"
-	"code.vikunja.io/api/pkg/red"
-	"github.com/go-redis/redis/v7"
+	"code.vikunja.io/api/pkg/modules/keyvalue"
+	e "code.vikunja.io/api/pkg/modules/keyvalue/error"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
 )
 
-var r *redis.Client
-
 const (
 	// ListCountKey is the name of the key in which we save the list count
 	ListCountKey = `listcount`
@@ -46,8 +44,6 @@ const (
 
 // InitMetrics Initializes the metrics
 func InitMetrics() {
-	r = red.GetRedis()
-
 	// init active users, sometimes we'll have garbage from previous runs in redis instead
 	if err := PushActiveUsers(); err != nil {
 		log.Fatalf("Could not set initial count for active users, error was %s", err)
@@ -101,18 +97,21 @@ func InitMetrics() {
 
 // GetCount returns the current count from redis
 func GetCount(key string) (count int64, err error) {
-	count, err = r.Get(key).Int64()
-	if err != nil && err.Error() != "redis: nil" {
-		return
+	cnt, err := keyvalue.Get(key)
+	if err != nil {
+		if e.IsErrValueNotFoundForKey(err) {
+			return 0, nil
+		}
+		return 0, err
 	}
-	err = nil
+	count = cnt.(int64)
 
 	return
 }
 
 // SetCount sets the list count to a given value
 func SetCount(count int64, key string) error {
-	return r.Set(key, count, 0).Err()
+	return keyvalue.Put(key, count)
 }
 
 // UpdateCount updates a count with a given amount
@@ -121,13 +120,13 @@ func UpdateCount(update int64, key string) {
 		return
 	}
 	if update > 0 {
-		err := r.IncrBy(key, update).Err()
+		err := keyvalue.IncrBy(key, update)
 		if err != nil {
 			log.Error(err.Error())
 		}
 	}
 	if update < 0 {
-		err := r.DecrBy(key, update).Err()
+		err := keyvalue.DecrBy(key, update)
 		if err != nil {
 			log.Error(err.Error())
 		}
diff --git a/pkg/modules/keyvalue/keyvalue.go b/pkg/modules/keyvalue/keyvalue.go
index b2371c9ea..d27f2db51 100644
--- a/pkg/modules/keyvalue/keyvalue.go
+++ b/pkg/modules/keyvalue/keyvalue.go
@@ -59,3 +59,13 @@ func Get(key string) (value interface{}, err error) {
 func Del(key string) (err error) {
 	return store.Del(key)
 }
+
+// IncrBy increases a value at key by the amount in update
+func IncrBy(key string, update int64) (err error) {
+	return store.IncrBy(key, update)
+}
+
+// DecrBy increases a value at key by the amount in update
+func DecrBy(key string, update int64) (err error) {
+	return store.DecrBy(key, update)
+}
diff --git a/pkg/routes/metrics.go b/pkg/routes/metrics.go
index a0a9031c7..61722f069 100644
--- a/pkg/routes/metrics.go
+++ b/pkg/routes/metrics.go
@@ -33,10 +33,6 @@ func setupMetrics(a *echo.Group) {
 		return
 	}
 
-	if !config.RedisEnabled.GetBool() {
-		log.Fatal("You have to enable redis in order to use metrics")
-	}
-
 	metrics.InitMetrics()
 
 	type countable struct {