Add creating `/data/db` directory for persistent storage

entrypoint.sh.template

@@ -1,5 +1,9 @@
 #!/bin/bash
 
+# Make sure `/data/db` directory exists even with persistent storage
+mkdir -p /data/db
+# If app crashed, mongo didn't stop gracefully. Remove all the old *.lock files
+find /data/db -name "*.lock" -type f -exec rm -f {} \; 
 # Start the local Mongo database
 mongod &