Add support for Redis key prefix config.

cmd/chirpstack-network-server/cmd/configfile.go

@@ -127,6 +127,14 @@ pool_size={{ .Redis.PoolSize }}
 # used by the server.
 tls_enabled={{ .Redis.TLSEnabled }}
 
+# Key prefix.
+#
+# A key prefix can be used to avoid key collisions when multiple regions
+# are using the same Redis database and it is not possible to separate
+# keys by database index (e.g. when using Redis Cluster, which does not
+# support multiple databases).
+key_prefix="{{ .Redis.KeyPrefix }}"
+
 
 # Network-server settings.
 [network_server]

internal/config/config.go

@@ -35,6 +35,7 @@ type Config struct {
 		Password   string   `mapstructure:"password"`
 		Database   int      `mapstructure:"database"`
 		TLSEnabled bool     `mapstructure:"tls_enabled"`
+		KeyPrefix  string   `mapstructure:"key_prefix"`
 	} `mapstructure:"redis"`
 
 	NetworkServer struct {

internal/storage/storage.go

@@ -22,12 +22,16 @@ var deviceSessionTTL time.Duration
 // scheduler runs.
 var schedulerInterval time.Duration
 
+// keyPrefix for Redis.
+var keyPrefix string
+
 // Setup configures the storage backend.
 func Setup(c config.Config) error {
 	log.Info("storage: setting up storage module")
 
 	deviceSessionTTL = c.NetworkServer.DeviceSessionTTL
 	schedulerInterval = c.NetworkServer.Scheduler.SchedulerInterval
+	keyPrefix = c.Redis.KeyPrefix
 
 	log.Info("storage: setting up Redis client")
 	if len(c.Redis.Servers) == 0 {
@@ -126,5 +130,5 @@ func Transaction(f func(tx sqlx.Ext) error) error {
 
 // GetRedisKey returns the Redis key given a template and parameters.
 func GetRedisKey(tmpl string, params ...interface{}) string {
-	return fmt.Sprintf(tmpl, params...)
+	return keyPrefix + fmt.Sprintf(tmpl, params...)
 }

internal/storage/storage_test.go

@@ -55,10 +55,16 @@ func TestGetRedisKey(t *testing.T) {
 	assert := require.New(t)
 
 	tests := []struct {
-		template string
-		params   []interface{}
-		expected string
+		keyPrefix string
+		template  string
+		params    []interface{}
+		expected  string
 	}{
+		{
+			keyPrefix: "eu868:",
+			template:  "foo:bar:key",
+			expected:  "eu868:foo:bar:key",
+		},
 		{
 			template: "foo:bar:key",
 			expected: "foo:bar:key",
@@ -71,6 +77,7 @@ func TestGetRedisKey(t *testing.T) {
 	}
 
 	for _, tst := range tests {
+		keyPrefix = tst.keyPrefix
 		out := GetRedisKey(tst.template, tst.params...)
 		assert.Equal(tst.expected, out)
 	}