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?

Liliyan Krumov · Accepted Answer · 2020-11-15 14:09:20Z

11

Logging from Microsoft to it's finest.

AzureWebJobsStorage App Setting was missing.

Solution:

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

answered Nov 15, 2020 at 14:09

Liliyan Krumov

1711 gold badge1 silver badge9 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Red · Accepted Answer · 2022-06-09 14:54:09Z

2

In my case the error was Microsoft.Extensions.Configuration.AzureAppConfiguration value cannot be null: parameter (connectionString)

This happened because I has installed Microsoft.Extensions.Configuration.AzureAppConfiguration in my Function to DI the configuration into my main function. The Startup.cs line string cs = Environment.GetEnvironmentVariable("MyDifferentConnectionString"); was not able to find an environment variable for MyDifferentConnectionString, so this needed to be added to the Function config.

Go to App Configuration (or create one)
Access Keys (under Settings)
Copy Connection String
Go to your Function
Configuration (under Settings)
Add a new Application Settings with the name of your environment variable and paste the value
Save and restart your Function

answered Jun 9, 2022 at 14:54

Red

3,3663 gold badges26 silver badges44 bronze badges

2 Comments

Teerasej Over a year ago

I confirmed this solution solves the problem of connecting the Azure App Configuration service with Azure Functions.

Adam Schumph Over a year ago

I'll echo that this solved my problem. I had originally put the connection string in the "Connection Strings" section, but that's not where GetEnvironmentalVariable looks.

user1069816 · Accepted Answer · 2023-11-22 16:28:26Z

2

If this is for local development using the local Azurite emulator then putting this into local.settings.json fixes it.

"AzureWebJobsStorage": "UseDevelopmentStorage=true"

More details here: https://learn.microsoft.com/en-us/azure/azure-functions/functions-develop-local#local-storage-emulator

answered Nov 22, 2023 at 16:28

user1069816

2,9412 gold badges30 silver badges46 bronze badges

1 Comment

Gregory Over a year ago

This is the actual solution.

Muni Chittem · Accepted Answer · 2023-03-14 11:43:04Z

1

this is deployment issue, I just copied settings from appsettings.json /localsettings.json files into configuration section.

answered Mar 14, 2023 at 11:43

Muni Chittem

1,15612 silver badges18 bronze badges

Collectives™ on Stack Overflow

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

4 Answers 4

Comments

2 Comments

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

2 Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related