add /tmp directory for accessing and change confinement to classic.

snap/snapcraft.yaml

@@ -6,7 +6,7 @@ description: |
   TDengine is an open-source big data platform designed and optimized for Internet of Things (IoT), Connected Vehicles, and Industrial IoT. Besides the 10x faster time-series database, it provides caching, stream computing, message queuing and other functionalities to reduce the complexity and costs of development and operations.
 
 grade: stable
-confinement: strict
+confinement: classic
 
 apps:
   tdengine:
@@ -30,9 +30,11 @@ plugs:
     read:
       - /etc/taos
       - /var/lib/taos
+      - /tmp
     write:
       - /var/log/taos
       - /var/lib/taos
+      - /tmp
 
 parts:
   script: