feat: add IM service health and metrics endpoints

docker/tinode/Dockerfile

@@ -223,9 +223,9 @@ RUN mkdir /botdata
 RUN chmod +x entrypoint.sh
 RUN chmod +x credentials.sh
 
-# Healthcheck: check if port 6060 is open
+# Healthcheck: verify the process and database dependency are responsive.
 HEALTHCHECK --interval=1m --timeout=3s --start-period=30s \
-  CMD nc -z localhost 6060 || exit 1
+  CMD wget -q -O /dev/null http://localhost:6060/healthz || exit 1
 
 # Generate config from template and run the server.
 ENTRYPOINT ["./entrypoint.sh"]

docker/tinode/Dockerfile.build

@@ -123,7 +123,7 @@ RUN mkdir -p /botdata static \
     && chmod +x entrypoint.sh credentials.sh tinode init-db apply-hotgo-tenant-db
 
 HEALTHCHECK --interval=1m --timeout=3s --start-period=30s \
-  CMD nc -z localhost 6060 || exit 1
+  CMD wget -q -O /dev/null http://localhost:6060/healthz || exit 1
 
 ENTRYPOINT ["./entrypoint.sh"]