Access to Cosmos db emulator on local machine from Linux docker - docker

Question

I little confused with Linux docker and cosmos db emulator. I have an emulator installed on my local machine. On my Windows 10 I have a Linux docker container with Web API ASP.NET core application. When I try to get access from container to cosmos db I get an exception -> HttpRequestException: Connection refused.
In C# code I get needed options like AuthKey and Uri to database from environment variables. Looks like I have an issue with network between container and localhost but I can not understand how I can connect these.
Below provided docker-compose.yml and docker-compose.override.yml files.
event.webapi:
container_name: event.webapi
image: '${DOCKER_REGISTRY-}eventwebapi'
environment:
**- AzureCollectionName=Events
- AzureDatabaseName=EventsDatabase**
build:
context: .
dockerfile: src/Services/Event/Event.WebApi/Dockerfile
``` docker-compose.override.yml
event.webapi:
environment:
- ASPNETCORE_ENVIRONMENT=Development
- ASPNETCORE_URLS=https://+:443;http://+:80
- ASPNETCORE_HTTPS_PORT=44378
**- AzureEndpointUri=https://127.0.0.1:8081
-AzurePrimaryKey=C2y6yDjf5/R+ob0N8A7Cgv30VRDJIWEHLM+4QDU5DE2nQ9nDuVTqobD4b8mGGyPMbIZnqyMsEcaGQy67XIw/Jw==**
ports:
- "53753:80"
- "44378:443"
volumes:
- ${APPDATA}/Microsoft/UserSecrets:/root/.microsoft/usersecrets:ro
- ${APPDATA}/ASP.NET/Https:/root/.aspnet/https:ro

Answer 1

You can't access vm host from docker container inside by setting https://127.0.0.1:8081 directly.
Please refer to this document, and try to set host.docker.internal:8081 to access vm host.
The host has a changing IP address (or none if you have no network
access). From 18.03 onwards our recommendation is to connect to the
special DNS name host.docker.internal, which resolves to the internal
IP address used by the host. This is for development purpose and will
not work in a production environment outside of Docker Desktop for
Windows.
Cosmos DB emulator needs installed SSL certificate,according to this link. For .net runtime, you could access the certificate directly from the Windows Certificate Store.
However, you run the .net code in linux docker image.So my idea is exporting SSL certificate following these steps.
Save it in the specific path on the host and mounting host directories.Please refer to this guide.