Run multiple containers on same docker network localhost - docker

Question

I want to connect from my app to mongodb on localhost, so they need to have same localhost address.
So the question is: Can two containers share they localhost, or for each container the localhost ip must be different?
I'm doing this for test environment purposes, so I don't want in-memory database, changed mongo uri or any different solution. I just want to connect from A to B by localhost.
To run my network and containers i type:
docker network create --driver bridge isolated_nw
docker run --name mongodb -d -p 27017:27017 --network=isolated_nw mongo:3.4.2
docker run --name roomate-profiles --network=isolated_nw -d -p 8080:8080 sovas/roomate-profiles
My custom docker network:
[
{
"Name": "isolated_nw",
"Id": "3efd6831784c2a8c9e9ea345144fcc6b9180e70c0e1b4b5d1a72219051b24e67",
"Scope": "local",
"Driver": "bridge",
"EnableIPv6": false,
"IPAM": {
"Driver": "default",
"Options": {},
"Config": [
{
"Subnet": "172.18.0.0/16",
"Gateway": "172.18.0.1/16"
}
]
},
"Internal": false,
"Containers": {
"57d4e2fb1f0c8d776329fd6ce82e5905df00e261ab6923595578dcb35913b03e": {
"Name": "roomate-profiles",
"EndpointID": "5a8158dc1aba6958218d1cca3c98ca911ab2cfa73be839ceece2e7819b244c91",
"MacAddress": "02:42:ac:12:00:03",
"IPv4Address": "172.18.0.3/16",
"IPv6Address": ""
},
"8fa815735d7ebb77434f8abf11e58f18faeb5d67e2743903d81f4600bd558c35": {
"Name": "mongodb",
"EndpointID": "7b7a7ed1ad08bbe381fb6d66c6e9fea66ee9b7c581f530bdf4d82f0741bff04b",
"MacAddress": "02:42:ac:12:00:02",
"IPv4Address": "172.18.0.2/16",
"IPv6Address": ""
}
},
"Options": {},
"Labels": {}
}
]
application.properties
spring.data.mongodb.uri=mongodb://localhost:27017/admin

Answer 1

localhost won't work since it refers to the roomate-profiles container. But you can do
spring.data.mongodb.uri=mongodb://mongodb:27017/admin
since both containers are connected to the same network. There is also no need to map the mongodb port to the host (unless you need it for something else).