Mongodb not accessible on host when run via docker-compose but works via docker - mongodb

Question

I`m trying to connect to mongodb in docker container from a host ( for dev purposes solely) without any luck.
I have following docker-compose file.
version: '2.2'
services:
mongo:
image: mongo
ports:
- "27017:21017"
And when i try to connect to it i'm getting following error:
C:\Program Files\MongoDB\Server\3.4\bin>mongo
MongoDB shell version v3.4.9
connecting to: mongodb://127.0.0.1:27017
2017-10-25T03:48:53.331+0300 E QUERY [thread1] Error: network error while attempting to run command 'isMaster' on host '127.0.0.1:27017' :
connect#src/mongo/shell/mongo.js:237:13
#(connect):1:6
exception: connect failed
But if i launch it without compose directly e.g.
docker run --name my_mongox6 -d -p 27017:27017 mongo
Which should be equivalent of the docker-compose file above.
And it works perfectly fine
C:\Program Files\MongoDB\Server\3.4\bin>mongo
MongoDB shell version v3.4.9
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 3.4.9
Server has startup warnings:
2017-10-25T00:49:58.983+0000 I STORAGE [initandlisten]
2017-10-25T00:49:58.983+0000 I STORAGE [initandlisten] ** WARNING: Using the XFS filesystem is strongly recommended with the WiredTiger storage engine
2017-10-25T00:49:58.983+0000 I STORAGE [initandlisten] ** See http://dochub.mongodb.org/core/prodnotes-filesystem
2017-10-25T00:49:59.076+0000 I CONTROL [initandlisten]
2017-10-25T00:49:59.076+0000 I CONTROL [initandlisten] ** WARNING: Access control is not enabled for the database.
2017-10-25T00:49:59.076+0000 I CONTROL [initandlisten] ** Read and write access to data and configuration is unrestricted.
2017-10-25T00:49:59.076+0000 I CONTROL [initandlisten]
Versions
c:\Program Files\MongoDB\Server\3.4\bin>docker --version
Docker version 17.09.0-ce, build afdb6d4
c:\Program Files\MongoDB\Server\3.4\bin>docker-compose --version
docker-compose version 1.16.1, build 6d1ac219
I'm using docker for windows that is run via hyper-v.
Whats wrong with my compose file and why it works via docker run but doesn't work via docker-compose. I'm scratching my head and googling without any luck for hours
Other port sharing via docker-compose ( e.g. nginx, postgresql) works perfectly fine.
UPDATE
Asked friend on ubuntu to try. Same behaviour. So its reproducible and its not specific to windows at all.. Works via docker, doesnt work via docker-compose. Even when i try to connect via telnet mongo logs show connect attempts when running via docker, but nothing shown when run via compose.
Also I see a difference in docker ps when run via compose vs when run via docker.
Ports on compose listed as
( 27017/tcp, 0.0.0.0:27017->21017/tcp )
vs
(0.0.0.0:27017->21017/tcp )
on docker itself.
It missed first 27017/tcp part which might be the issue, but no idea why.

Answer 1

Ok, the problem is super stupid and simple.
ports: - "27017:21017"
second port 21017 instead of 27017. How to waste full day due to typo

Answer 2

If you are on linux it works fine. When you run container in windows you need to do port farwarding.
netsh interface portproxy add v4tov4 listenport=27017 listenaddress=localhost connectport=27017 connectaddress=192.168.99.100(IP of the Docker)
Whatever the call comming to loopback it will get redirected to container with the docker host.
Here is the helping discussion on port farwarding in windows with docker Solution for Windows hosts
This lines I'm using docker for windows that is run via hyper-v., say that you ae on Windows and docker will not be the loopback(127.0.0.1), you have to forward the port.