Cosmos DB trigger is not connecting to CosmosDB Emulator

Hi Azure Functions Team, I have an Azure Functions App consisting of HttpTrigger Functions and CosmosDbTrigger Functions. Both kind of functions work fine and can connect against an actual CosmosDB instance. Unfortunately, when running against the CosmosDB emulator the CosmosDBTrigger Functions fail to connect against the CosmosDB emulator. The errors that I receive are of the following form:

[2022-01-15T18:17:06.601Z] Error indexing method 'Functions.feed'
[2022-01-15T18:17:06.601Z] Microsoft.Azure.WebJobs.Host: Error indexing method 'Functions.feed'. Microsoft.Azure.WebJobs.Extensions.CosmosDB: Cannot create Collection Information for Article in database ##-db with lease leases in database ##-db : The SSL connection could not be established, see inner exception. System.Net.Http: The SSL connection could not be established, see inner exception. System.Private.CoreLib: The remote certificate is invalid according to the validation procedure: RemoteCertificateNameMismatch.

The settings of the app look like below:

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "DefaultEndpointsProtocol=https;AccountName=###;AccountKey=###;EndpointSuffix=core.windows.net",
    "FUNCTIONS_WORKER_RUNTIME": "node",
    "DATABASE_CONNECTION_STRING": "AccountEndpoint=https://##.###.###.###:8081/;AccountKey=<DEFAULT_PRIMARY_KEY>"
   }
}

Though, the remaining HttpTrigger functions can communicate with the CosmosDB emulator via the SDK’s CosmosClient. For this to work NODE_TLS_REJECT_UNAUTHORIZED=0 is set. But as the error looks like coming form the .NET functions tool itself not from any of our node application, it looks like this setting is not helping.

The CosmosDB emulator is setup as lined out in an answer to #1232 with the deviation that the local development is done on OSX, which is why the certificate import is different. And it looks like the imported certificate is ignored by .NET.

I believe a similar, if not same question was raised in #2024 was closed, but not solved. At least nothing I can find there helps me in resolving the described issues.

I’m not sure what else to try and would really appreciate any help at all 😃

[ealsur]

Do you build the Functions mostly on C#? I think that a solution like the second one (add a config as a boolean value) could be the one that tackles this problem across languages.

[macel94]

Hi @ealsur @michaelpeng36

i’m developing a simple but complex enough example to really try to understand how developing in containers would really be for me and my team in next projects. I’m really finding it hard to solve this simple thing of triggering my azfunction

i’m using everything with the latest packages and everything is public beside the secret i was required to create(not my choice) to be able to use azure service bus.

if you want to repro this bug i believe i can help, if you want to take a look here: https://github.com/MACEL94/advanced-azure-microservices-with-dotnet-for-developers/tree/9-manage-to-make-everything-work-locally-with-just-a-docker-compose-up

everything is on linux as i’m trying to develop on codespaces

thank you anyway for your help