CODEWITHSUNDEEP
azure-functionsazure-functions-runtime
jtlz2
jtlz2

Reputation: 8407

Azure Functions: How do I launch only a specific Function in local dev environment?

If I want to launch all available functions in the dev environment, I simply do:

 func host start

Is there a way to choose a subset of the available functions, without having to move the intended-to-be-deactivated ones out of the working directory etc.?

PS I am using Python for the Function itself.

Upvotes: 5

Views: 5153

Answers (3)

Esteban Rincon
Esteban Rincon

Reputation: 2110

I use func start --functions [a space separated list of functions]

This is with azure-functions-core-tools@3

According to:

--port [-p]        Local port to listen on. Default: 7071
--cors             A comma separated list of CORS origins with no spaces. Example: https://functions.azure.com,https://functions-staging.azure.com
--cors-credentials Allow cross-origin authenticated requests (i.e. cookies and the Authentication header)
--timeout [-t]     Timeout for on the functions host to start in seconds. Default: 20 seconds.
--useHttps         Bind to https://localhost:{port} rather than http://localhost:{port}. By default it creates and trusts a certificate.
--cert             for use with --useHttps. The path to a pfx file that contains a private key
--password         to use with --cert. Either the password, or a file that contains the password for the pfx file
--language-worker  Arguments to configure the language worker.
--no-build         Do no build current project before running. For dotnet projects only. Default is set to false.
--enableAuth       Enable full authentication handling pipeline.
--functions        A space seperated list of functions to load.

Upvotes: 9

George Chen
George Chen

Reputation: 14324

There are three ways to implement it.

  1. Disable functions:

One is modifying the function.json:

"bindings": [
    ...
],
"disabled": "IS_DISABLED"

Another is use Disable attribute to prevent a function from being triggered.

    [Disable]
 [FunctionName("Function")]
 [NoAutomaticTrigger]
 public static void Function(string input, TraceWriter log)
{
}

  1. With Azure Functions Core Tools, only for version 1.x

    func run <functionName>

  2. host.json:

    {
 "functions": [ "QueueProcessor", "GitHubWebHook" ]
}

Update:

4: as jtlz2 answered, this way is for disable functions locally with local.settings.json.

{
  "Values": {
     "AzureWebJobs.MyFunctionName.Disabled": true
     "AzureWebJobs.MyFunctionName2.Disabled": false
   }
}

**Update:**as @ahmelsayed explains something about there are many options to call only one function, so i update it here.

"Disabled" is meant to be used to dynamically turn a function on or off. The runtime will still load the function, and will display any errors or issues with the function (incorrect settings etc), but will not execute the code. There are many ways to enable/disable a function because some want to keep that in source control and for some it's a devops operation

The functions array in host.json is something I wasn't initially aware of. It was added to the runtime for the convenience of the runtime developers who have a large folder of samples that they wanted to be able to load only a subset of. This completely ignores functions that are not listed. They won't be indexed or loaded in anyway.

Upvotes: 9

jtlz2
jtlz2

Reputation: 8407

It seems there has been some consternation over disabling Functions lately.

As pointed out at https://github.com/Azure/Azure-Functions/issues/736#issuecomment-471072316, one can make use of local.settings.json to achieve this. Simply add to it:

{
  "Values": {
    "AzureWebJobs.MyFunctionName.Disabled": true
    "AzureWebJobs.MyFunctionName2.Disabled": false
  }
}

etc.

I'd be interested to hear if there is a better way, e.g. setting it from the command line when executing func host start.

Upvotes: 2

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