MongoDb ReplicaSet in container, accessable on bridge and host network - mongodb

Question

I am running 3 MongoDB instances in a container named mongodb-local, and initiating them as a replica set with the command:
mongo --port 27020 --eval 'rs.initiate({_id: "rs1", members: [ { _id: 0, host: "mongodb-local:27018"}, { _id: 1, host: "mongodb-local:27019"}, { _id: 2, host: "mongodb-local:27020"} ] })'
This allows the MongoDB instances to talk to other services on the bridge network as mongodb://mongodb-local:27018,mongodb-local:27019,mongodb-local:27020/?replicaSet=rs1
However, I also want to connect to the MongoDB replica-set from the host/public. I have published the 3 ports there, however attempting to connect to and use mongodb://localhost:27018,localhost:27019,localhost:27020/?replicaSet=rs1 fails because the replicas know eachother as mongodb-local, which is not resolvable to the host.
Errors for example in the c# driver such as:
One or more errors occurred. (A timeout occured after 30000ms selecting a server using CompositeServerSelector{ Selectors = MongoDB.Driver.MongoClient+AreSessionsSupportedServerSelector, LatencyLimitingServerSelector{ AllowedLatencyRange = 00:00:00.0150000 } }. Client view of cluster state is { ClusterId : "1", ConnectionMode : "ReplicaSet", Type : "ReplicaSet", State : "Disconnected", Servers : [{ ServerId: "{ ClusterId : 1, EndPoint : "Unspecified/localhost:27018" }", EndPoint: "Unspecified/localhost:27018", State: "Disconnected", Type: "Unknown", HeartbeatException: "MongoDB.Driver.MongoConnectionException: An exception occurred while opening a connection to the server.
or in the shell
...>mongo mongodb://localhost:27020,localhost:27019,localhost:27018/?replicaSet=rs1
MongoDB shell version v4.0.2
connecting to: mongodb://localhost:27020,localhost:27019,localhost:27018/?replicaSet=rs1
2020-07-22T11:24:23.036+0100 I NETWORK [js] Starting new replica set monitor for rs1/localhost:27020,localhost:27019,localhost:27018
2020-07-22T11:24:23.042+0100 I NETWORK [js] Successfully connected to localhost:27018 (1 connections now open to localhost:27018 with a 5 second timeout)
2020-07-22T11:24:23.042+0100 I NETWORK [ReplicaSetMonitor-TaskExecutor] Successfully connected to localhost:27019 (1 connections now open to localhost:27019 with a 5 second timeout)
2020-07-22T11:24:23.046+0100 I NETWORK [ReplicaSetMonitor-TaskExecutor] Successfully connected to localhost:27020 (1 connections now open to localhost:27020 with a 5 second timeout)
2020-07-22T11:24:23.048+0100 I NETWORK [ReplicaSetMonitor-TaskExecutor] changing hosts to rs1/mongodb-local:27018,mongodb-local:27019,mongodb-local:27020 from rs1/localhost:27018,localhost:27019,localhost:27020
2020-07-22T11:24:28.563+0100 W NETWORK [js] Unable to reach primary for set rs1
2020-07-22T11:24:28.563+0100 I NETWORK [js] Cannot reach any nodes for set rs1. Please check network connectivity and the status of the set. This has happened for 1 checks in a row.
2020-07-22T11:24:32.072+0100 W NETWORK [js] Unable to reach primary for set rs1
2020-07-22T11:24:32.072+0100 I NETWORK [js] Cannot reach any nodes for set rs1. Please check network connectivity and the status of the set. This has happened for 2 checks in a row.
2020-07-22T11:24:35.581+0100 W NETWORK [js] Unable to reach primary for set rs1
2020-07-22T11:24:35.581+0100 I NETWORK [js] Cannot reach any nodes for set rs1. Please check network connectivity and the status of the set. This has happened for 3 checks in a row.
2020-07-22T11:24:39.091+0100 W NETWORK [js] Unable to reach primary for set rs1
2020-07-22T11:24:39.092+0100 I NETWORK [js] Cannot reach any nodes for set rs1. Please check network connectivity and the status of the set. This has happened for 4 checks in a row.
2020-07-22T11:24:39.097+0100 E QUERY [js] Error: connect failed to replica set rs1/localhost:27020,localhost:27019,localhost:27018 :
connect#src/mongo/shell/mongo.js:257:13
#(connect):1:6
exception: connect failed
Conversely, I could initiate the replica set as:
mongo --port 27020 --eval 'rs.initiate({_id: "rs1", members: [ { _id: 0, host: "localhost:27018"}, { _id: 1, host: "localhost:27019"}, { _id: 2, host: "localhost:27020"} ] })'
Which will allow connections from the host machine/public, and by coincedence since the replicas are all running on the same container, they can also talk to eachother.
However, other services cannot connect with mongodb://mongodb-local:27018,mongodb-local:27019,mongodb-local:27020/?replicaSet=rs1, with a similar error.
This would also fail if I wanted to put each replica on a separate container.
I believe this is because the client receives the replica-set record after connecting and expects that to be available on the network it is connecting from? This is not a great assumption if so.
How can I initiate the replica-set on the bridge network and also allow connections from outside the bridge network?