docker-compose MongoDB replica set data loss after some period of time - mongodb

Question

Below is the docker-compose.yml I have used.
MongoDB container got created, after some 6 to 8 hours of time the databases inside the mongo are getting cleared of automatically.
Even after the manual restart I could not able to get my data back.
I have followed two approaches, and still could not able to figure out what's the issue.
Should I need to declare volumes at the top of the compose file like in approach 1 or provide user specific directory "./data/mongo-1" like in approach 2
Adding the below will it help?
volumes:
mongo_data:
driver: local # not working
external: true # will it work?
Approach-1: Single node replica set
version: '3.8'
volumes:
mongo_data:
mongodb:
hostname: mongodb
container_name: mongodb
image: mongo:latest
environment:
MONGO_INITDB_DATABASE: moviebooking
MONGO_REPLICA_SET_NAME: rs0
volumes:
- ./mongo-initdb.d:/docker-entrypoint-initdb.d
- mongo_data:/data/db
expose:
- 27017
ports:
- "27017:27017"
restart: unless-stopped
healthcheck:
test: test $$(echo "rs.initiate().ok || rs.slaveOk().ok || rs.status().ok" | mongo --quiet) -eq 1
interval: 10s
start_period: 30s
entrypoint: [ "/usr/bin/mongod", "--bind_ip_all", "--replSet", "rs0" ]
Approach-2: Multi node replica set
version: '3.8'
services:
mongo1:
image: mongo:4.2
container_name: mongo1
command: ["--replSet", "my-replica-set", "--bind_ip_all", "--port", "27017"]
volumes:
- ./data/mongo-1:/data/db
ports:
- 27017:27017
healthcheck:
test: test $$(echo "rs.initiate({_id:'my-replica-set',members:[{_id:0,host:\"mongo1:27017\"},{_id:1,host:\"mongo2:27018\"},{_id:2,host:\"mongo3:27019\"}]}).ok || rs.status().ok" | mongo --port 27017 --quiet) -eq 1
interval: 10s
start_period: 30s
mongo2:
image: mongo:4.2
container_name: mongo2
command: ["--replSet", "my-replica-set", "--bind_ip_all", "--port", "27018"]
volumes:
- ./data/mongo-2:/data/db
ports:
- 27018:27018
mongo3:
image: mongo:4.2
container_name: mongo3
command: ["--replSet", "my-replica-set", "--bind_ip_all", "--port", "27019"]
volumes:
- ./data/mongo-3:/data/db
ports:
- 27019:27019

Answer 1

In my case , db was hacked by some one.
Adding volume mount will work, making it as external in compose will ask you to create a volume externally before running the compose file. Which I feel is a safe way instead of asking compose to decide the volume location.
you are welcome :)