Azure Functions - Value cannot be null. (Parameter 'connectionString')

Question

I was trying to setup simple Azure Function to read a XML stream and sync it back to the database. My plan was to use a Time Trigger to execute the function once per day.

Howerver, things are not looking great. I'm getting the following error, even if I don't use a database:

[Error] Executed 'Functions.<func-name>' (Failed, Id=<func-id>, Duration=1ms)Value cannot be null. (Parameter 'connectionString')

I'm currently trying to execute the following function:

module.exports = async function(context, req) {
    context.res = {
        body: "Success!"
    };
};

Same result. I can't run it.

I've added a Connection String to the Configuration -> Connection Strings (I thought that I've missed that, based on the message).

My functions.json file looks like:

{
  "bindings": [
    {
      "name": "myTimer",
      "type": "timerTrigger",
      "direction": "in",
      "schedule": "0 0 * * * *"
    },
    {
      "type": "http",
      "direction": "out",
      "name": "res"
    }
  ]
}

I've also tried running a C# function - same result.

So, what have I missed?

Answer 1

Logging from Microsoft to it's finest.

AzureWebJobsStorage App Setting was missing.

Solution:

1. Create Storage account (or use existing one)
2. Go to your Function App's Configuration
3. Add AzureWebJobsStorage with a connection string to your Storage account (can be found at Storage Account Overview -> Access Keys)