[FEATURE REQ] mgmt function app, convenience API for creating function app with managedEnvironmentId

[XiaofeiCao]

docs: https://learn.microsoft.com/en-us/azure/azure-functions/functions-container-apps-hosting

It's a new hosting plan compared to previous App Service Plans: All hosting plans

Some major implementation differences(found in azure-cli, may not be exhaustive):
For managed container app environment based(Centauri) Function Apps

1. SiteConfig needs to be set to SiteInner.siteConfig when creating FunctionApp, instead of updating SiteConfig after Function App is created. Though future update on site configs will be using update method.
2. Some property values are different, e.g. kind in SiteInner need to be "functionapp,linux,container,azurecontainerapps"
3. Some update methods(updateSiteConfig, updateAppSettings) are LRO for Centauri Function Apps, but not defined as such in swagger. Need to manual poll. 

Tasks

Beta Give feedback

1. Test cases for function app on ACA
2. Interface design
3. [Implementation investigation] SiteConfig behavior change
4. [Implementation investigation] SiteInner property modifications
5. [Implementation investigation] manual LRO for updating SiteConfig and AppSettings
6. Interface Implementation
7. Alpha release for tooling team
8. Stable release

[weidongxu-microsoft]

For (3), should we ask service to fix?

LRO not marked as LRO means every SDK fails.

[XiaofeiCao]

For (3), should we ask service to fix?

LRO not marked as LRO means every SDK fails.

Yeah, I'll ask them for confirmation. CLI team seems to be aware of this issue too:
https://github.com/Azure/azure-cli/blob/dev/src/azure-cli/azure/cli/command_modules/appservice/custom.py#L1558

[XiaofeiCao]

Use cases for function app on Azure Container Apps

Create function app with managed environment

FunctionApp functionApp = appServiceManager.functionApps().define(webappName)
    .withRegion(Region.US_EAST)
    .withNewResourceGroup(rgName1)
    .withManagedEnvironmentId(managedEnvironmentId) // create with managedEnvironmentId
    //.withManagedEnvironmentName(managedEnvironmentName) // create with managedEnvironmentName
    .withMaxReplicas(10) // with scale setting
    .withMinReplicas(3) // with scale setting
    .withBuiltInImage(FunctionRuntimeStack.JAVA_17)
    .withAppSetting("WEBSITE_RUN_FROM_PACKAGE", FUNCTION_APP_PACKAGE_URL)
    .create();

Update scale settings

functionApp.update()
    .withMaxReplicas(15) // with scale setting
    .withMinReplicas(5) // with scale setting
    .apply();

[XiaofeiCao]

2.34.0 released.