Add keep_alive_interval config for MQTT.

In case there is a loadbalancer between ChirpStack and the MQTT broker,
it is useful to have control over the keep-alive messages, to make sure
that the loadbalancer does not drop the connection if there is no
activity. In such a case you want to set the keep_alive_interval to a
lower interval than the loadbalancer timeout.

chirpstack/configuration/region_as923.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_as923_2.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_as923_3.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_as923_4.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_au915_0.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_au915_1.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_au915_2.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_au915_3.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_au915_4.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_au915_5.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_au915_6.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_au915_7.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_cn470_0.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_cn470_1.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_cn470_10.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_cn470_11.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_cn470_2.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_cn470_3.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_cn470_4.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_cn470_5.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_cn470_6.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_cn470_7.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_cn470_8.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_cn470_9.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_cn779.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_eu433.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_eu868.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_in865.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_ism2400.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_kr920.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_ru864.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_us915_0.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_us915_1.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_us915_2.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_us915_3.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_us915_4.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_us915_5.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_us915_6.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/configuration/region_us915_7.toml

@@ -66,6 +66,12 @@
         # a random id will be generated by ChirpStack.
         client_id=""
 
+        # Keep alive interval.
+        #
+        # This defines the maximum time that that should pass without communication
+        # between the client and server.
+        keep_alive_interval="30s"
+
         # CA certificate file (optional)
         #
         # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/src/cmd/configfile.rs

@@ -351,6 +351,12 @@ pub fn run() {
     # a random id will be generated by ChirpStack.
     client_id="{{ integration.mqtt.client_id }}"
 
+    # Keep alive interval.
+    #
+    # This defines the maximum time that that should pass without communication
+    # between the client and server.
+    keep_alive_interval="{{ integration.mqtt.keep_alive_interval }}"
+
     # CA certificate file (optional)
     #
     # Use this when setting up a secure connection (when server uses ssl://...)

chirpstack/src/config.rs

@@ -270,6 +270,8 @@ pub struct MqttIntegration {
     pub ca_cert: String,
     pub tls_cert: String,
     pub tls_key: String,
+    #[serde(with = "humantime_serde")]
+    pub keep_alive_interval: Duration,
 }
 
 impl Default for MqttIntegration {
@@ -289,6 +291,7 @@ impl Default for MqttIntegration {
             ca_cert: "".into(),
             tls_cert: "".into(),
             tls_key: "".into(),
+            keep_alive_interval: Duration::from_secs(30),
         }
     }
 }
@@ -537,8 +540,6 @@ impl Default for Region {
                         event_topic: "eu868/gateway/+/event/+".into(),
                         command_topic: "eu868/gateway/{{ gateway_id }}/command/{{ command }}"
                             .into(),
-                        server: "tcp://127.0.0.1:1883".into(),
-                        clean_session: false,
                         ..Default::default()
                     },
                 },
@@ -612,7 +613,7 @@ pub struct GatewayBackend {
     pub mqtt: GatewayBackendMqtt,
 }
 
-#[derive(Default, Serialize, Deserialize, Clone)]
+#[derive(Serialize, Deserialize, Clone)]
 #[serde(default)]
 pub struct GatewayBackendMqtt {
     pub event_topic: String,
@@ -626,6 +627,27 @@ pub struct GatewayBackendMqtt {
     pub ca_cert: String,
     pub tls_cert: String,
     pub tls_key: String,
+    #[serde(with = "humantime_serde")]
+    pub keep_alive_interval: Duration,
+}
+
+impl Default for GatewayBackendMqtt {
+    fn default() -> Self {
+        GatewayBackendMqtt {
+            event_topic: "".into(),
+            command_topic: "".into(),
+            server: "tcp://127.0.0.1:1883/".into(),
+            username: "".into(),
+            password: "".into(),
+            qos: 0,
+            clean_session: false,
+            client_id: "".into(),
+            ca_cert: "".into(),
+            tls_cert: "".into(),
+            tls_key: "".into(),
+            keep_alive_interval: Duration::from_secs(30),
+        }
+    }
 }
 
 #[derive(Serialize, Deserialize, Clone, Hash)]

chirpstack/src/gateway/backend/mqtt.rs

@@ -143,6 +143,7 @@ impl<'a> MqttBackend<'a> {
         let mut conn_opts_b = mqtt::ConnectOptionsBuilder::new();
         conn_opts_b.automatic_reconnect(Duration::from_secs(1), Duration::from_secs(30));
         conn_opts_b.clean_session(conf.clean_session);
+        conn_opts_b.keep_alive_interval(conf.keep_alive_interval);
         conn_opts_b.user_name(&conf.username);
         conn_opts_b.password(&conf.password);
         if !conf.ca_cert.is_empty() || !conf.tls_cert.is_empty() || !conf.tls_key.is_empty() {

chirpstack/src/integration/mqtt.rs

@@ -99,6 +99,7 @@ impl<'a> Integration<'a> {
         let mut conn_opts_b = mqtt::ConnectOptionsBuilder::new();
         conn_opts_b.automatic_reconnect(Duration::from_secs(1), Duration::from_secs(30));
         conn_opts_b.clean_session(conf.clean_session);
+        conn_opts_b.keep_alive_interval(conf.keep_alive_interval);
         conn_opts_b.user_name(&conf.username);
         conn_opts_b.password(&conf.password);
         if !conf.ca_cert.is_empty() || !conf.tls_cert.is_empty() || !conf.tls_key.is_empty() {