feat(mqtt): add option to set :clean-start

config.example.edn

@@ -14,7 +14,8 @@
                     :port 1883
                     :clientid "chan1"
                     :topic "t/sf/1"
-                    :qos 1}}
+                    :qos 1
+                    :clean-start false}}
             {:chan-name "my_channel2"
              :database "TESTDATABASE"
              :schema "PUBLIC"
@@ -24,4 +25,5 @@
                     :port 1883
                     :clientid "chan2"
                     :topic "t/sf/2"
-                    :qos 1}}]}
+                    :qos 1
+                    :clean-start false}}]}

src/emqx/adapter.clj

@@ -4,14 +4,15 @@
    [cheshire.core :as json]))
 
 (defn mqtt-client-config
-  [{:keys [:host :port :clientid :topic :qos :username :password]}]
+  [{:keys [:host :port :clientid :topic :qos :clean-start :username :password]}]
   {:uri (str "tcp://" host ":" port)
    :clientid clientid
    :topic topic
    :qos qos
    :opts (cond-> {:auto-reconnect true}
            username (assoc :username username)
-           password (assoc :password password))})
+           password (assoc :password password)
+           (boolean? clean-start) (assoc :clean-session clean-start))})
 
 (defn channel-data-in
   "Parses the incoming payload and expects it to be a JSON encoded object"

src/emqx/config.clj

@@ -20,6 +20,7 @@
    :clientid s/Str
    :topic s/Str
    :qos (s/enum 0 1 2)
+   (s/optional-key :clean-start) s/Bool
    (s/optional-key :username) s/Str
    (s/optional-key :password) s/Str})