"Azure Function" with Docker image is not working for "Azure Cosmos DB trigger"

Question

We have a Azure-Function with Docker image that works on a Http-Trigger ...as per this article .. https://learn.microsoft.com/en-us/azure/azure-functions/functions-deploy-container?tabs=acr%2Cbash%2Cazure-cli&pivots=programming-language-python

However when we add a CosmosDB trigger ... it would fail with

@app.function_name(name="CosmosDBTrigger")
@app.cosmos_db_trigger(
    arg_name="documents",
    connection="COSMOSDB_CONNECTION_STRING",
    database_name="sz-ue2XXXXX",
    container_name="****",
    lease_container_name="leases",
    create_lease_container_if_not_exists="true",
)
def CosmosDBTrigger(documents: func.DocumentList) -> str:
    if documents:
        logging.info("Document id: %s", documents[0]["id"])


2024-06-18T21:15:33.567Z ERROR - Container ****eto-s-func-01_1_153a76b5 for site sz-ue2-seto-s-func-01 did not start within expected time limit. Elapsed time = 230.4885576 sec
    2024-06-18T21:15:33.608Z ERROR - Container ****s-func-01_1_153a76b5 didn't respond to HTTP pings on port: 80, failing site start. See container logs for debugging.

Question 1: Can "Azure function with Docker image" have a trigger for "CosmosDB" ?

Question 2: If the answer is yes for question 1, then is there a sample of the Dockerfile ?

Thanks.

Answer 1

To trigger cosmos_db trigger in container function app you need to pass the Connection string value inside the Dockerfile.

Prerequisite for Cosmosdb Trigger

• leases container should be available inside the database with PartitionKey as /partitionKey.

funcdocker_DOCUMENTDB is my Connection name. Check ENV in docker file.

Dockerfile:

FROM mcr.microsoft.com/azure-functions/python:4-python3.11

ENV AzureWebJobsScriptRoot=/home/site/wwwroot \
    AzureFunctionsJobHost__Logging__Console__IsEnabled=true \
    funcdocker_DOCUMENTDB=AccountEndpoint=https://funcdocker.documents.azure.com:443/;AccountKey=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx;

COPY requirements.txt /
RUN pip install -r /requirements.txt

EXPOSE 443

COPY . /home/site/wwwroot

function_app.py:

import azure.functions as func
import logging

app = func.FunctionApp()


@app.cosmos_db_trigger(arg_name="azcosmosdb", container_name="Test",
                        database_name="ToDoList", connection="funcdocker_DOCUMENTDB") 
def cosmosdb_trigger(azcosmosdb: func.DocumentList):
    logging.info('Python CosmosDB triggered.')

OUTPUT: