Docker false positive on health check for MongoDB server - mongodb

Question

I want to setup a replica set with mongodb, and I want to detect all the servers are ready to use.
I have configured the following docker-compose file:
version: '3.8'
services:
mongo_launcher:
container_name: mongo_launcher
image: mongo:6.0.2
restart: on-failure
networks:
- dashboard_network
volumes:
- ./docker/scripts/mongo-setup.sh:/scripts/mongo-setup.sh
entrypoint: ['sh', '/scripts/mongo-setup.sh']
mongo_replica_1:
container_name: mongo_replica_1
image: mongo:6.0.2
ports:
- 27017:27017
restart: always
entrypoint:
[
'/usr/bin/mongod',
'--bind_ip_all',
'--replSet',
'dbrs',
'--dbpath',
'/data/db',
'--port',
'27017',
]
volumes:
- ./.volumes/mongo/replica1:/data/db
- ./.volumes/mongo/replica1/configdb:/data/configdb
networks:
- dashboard_network
mongo_replica_2:
container_name: mongo_replica_2
image: mongo:6.0.2
ports:
- 27018:27018
restart: always
entrypoint:
[
'/usr/bin/mongod',
'--bind_ip_all',
'--replSet',
'dbrs',
'--dbpath',
'/data/db',
'--port',
'27018',
]
volumes:
- ./.volumes/mongo/replica2:/data/db
- ./.volumes/mongo/replica2/configdb:/data/configdb
networks:
- dashboard_network
mongo_replica_3:
container_name: mongo_replica_3
image: mongo:6.0.2
ports:
- 27019:27019
restart: always
entrypoint:
[
'/usr/bin/mongod',
'--bind_ip_all',
'--replSet',
'dbrs',
'--dbpath',
'/data/db',
'--port',
'27019',
]
volumes:
- ./.volumes/mongo/replica3:/data/db
- ./.volumes/mongo/replica3/configdb:/data/configdb
networks:
- dashboard_network
My mongo-setup.sh file is:
#!/bin/bash
MONGODB_REPLICA_1=mongo_replica_1
MONGODB_REPLICA_2=mongo_replica_2
MONGODB_REPLICA_3=mongo_replica_3
echo "************ [ Waiting for startup ] **************" ${MONGODB_REPLICA_1}
until ncc -zvv ${MONGODB_REPLICA_1} 27017 2>&1 | grep uptime | head -1; do
printf '.'
sleep 1
done
echo "************ [ Startup completed ] **************" ${MONGODB_REPLICA_1}
mongosh --host ${MONGODB_REPLICA_1}:27017 <<EOF
var cfg = {
"_id": "dbrs",
"protocolVersion": 1,
"version": 1,
"members": [
{
"_id": 1,
"host": "${MONGODB_REPLICA_1}:27017",
"priority": 3
},
{
"_id": 2,
"host": "${MONGODB_REPLICA_2}:27018",
"priority": 2
},
{
"_id": 3,
"host": "${MONGODB_REPLICA_3}:27019",
"priority": 1
}
],settings: {chainingAllowed: true}
};
rs.initiate(cfg, { force: true });
rs.reconfig(cfg, { force: true });
rs.secondaryOk();
db.getMongo().setReadPref('nearest');
db.getMongo().setSecondaryOk();
EOF
If I check the logs of mongo_launcher, using docker logs mongo_launcher I get:
************ [ Waiting for startup ] ************** mongo_replica_1
************ [ Startup completed ] ************** mongo_replica_1
Current Mongosh Log ID: 6367f96a8273830a6762893c
Connecting to: mongodb://mongo_replica_1:27017/?directConnection=true&appName=mongosh+1.6.0
MongoNetworkError: connect ECONNREFUSED 172.21.0.3:27017
************ [ Waiting for startup ] ************** mongo_replica_1
************ [ Startup completed ] ************** mongo_replica_1
Current Mongosh Log ID: 6367f96c7b96e8524fb103e7
Connecting to: mongodb://mongo_replica_1:27017/?directConnection=true&appName=mongosh+1.6.0
MongoNetworkError: connect ECONNREFUSED 172.21.0.3:27017
************ [ Waiting for startup ] ************** mongo_replica_1
************ [ Startup completed ] ************** mongo_replica_1
Current Mongosh Log ID: 6367f96f9fd15a9ae8bc32d6
Connecting to: mongodb://mongo_replica_1:27017/?directConnection=true&appName=mongosh+1.6.0
MongoNetworkError: connect ECONNREFUSED 172.21.0.3:27017
************ [ Waiting for startup ] ************** mongo_replica_1
************ [ Startup completed ] ************** mongo_replica_1
Current Mongosh Log ID: 6367f972d8f575d837789d62
Connecting to: mongodb://mongo_replica_1:27017/?directConnection=true&appName=mongosh+1.6.0
MongoNetworkError: connect ECONNREFUSED 172.21.0.3:27017
************ [ Waiting for startup ] ************** mongo_replica_1
************ [ Startup completed ] ************** mongo_replica_1
Current Mongosh Log ID: 6367f9746bfa236397cf67a5
Connecting to: mongodb://mongo_replica_1:27017/?directConnection=true&appName=mongosh+1.6.0
MongoNetworkError: connect ECONNREFUSED 172.21.0.3:27017
************ [ Waiting for startup ] ************** mongo_replica_1
************ [ Startup completed ] ************** mongo_replica_1
Current Mongosh Log ID: 6367f97842ac739549b27e4a
Connecting to: mongodb://mongo_replica_1:27017/?directConnection=true&appName=mongosh+1.6.0
MongoNetworkError: connect ECONNREFUSED 172.21.0.3:27017
************ [ Waiting for startup ] ************** mongo_replica_1
************ [ Startup completed ] ************** mongo_replica_1
Current Mongosh Log ID: 6367f97cb586d80909d5b2f8
Does anyone could tell why the scripts passes the:
until ncc -zvv ${MONGODB_REPLICA_1} 27017 2>&1 | grep uptime | head -1; do
printf '.'
sleep 1
done
script, but fails to connect to mongo server? I don't want the script to skip this if condition, if the server is not ready..