02 - First Deploy (Flex Consumption)¶

Provision Azure resources and deploy the .NET 8 isolated worker reference application to the Flex Consumption (FC1) plan with repeatable CLI commands.

Prerequisites¶

Tool	Version	Purpose
.NET SDK	8.0 (LTS)	Build and run isolated worker functions
Azure Functions Core Tools	v4	Start local host and publish artifacts
Azure CLI	2.61+	Provision Azure resources and inspect app state
Azure subscription	Active	Target for deployment

Flex Consumption plan basics

Flex Consumption (FC1) keeps serverless economics while adding VNet integration, configurable instance memory (512 MB to 4096 MB), and per-function scaling. Microsoft recommends it for many new apps.

What You'll Build¶

You will provision a Linux Flex Consumption Function App for .NET 8 isolated worker, deploy with func azure functionapp publish from the compiled output directory, and validate HTTP endpoints.

Infrastructure Context

Plan: Flex Consumption (FC1) | Network: VNet integration supported | Storage auth: SystemAssigned MI

Flex Consumption uses blob-based deployment storage with managed identity authentication, unlike Consumption which uses Azure Files with connection strings.

flowchart TD
    INET[Internet] -->|HTTPS| FA[Function App\nFlex Consumption FC1\nLinux .NET 8 isolated]

    FA -->|"SystemAssigned MI"| ST[Storage Account\nBlob deployment]
    FA --> AI[Application Insights]

    subgraph STORAGE[Storage Services]
        ST --- DEPLOY["Blob Container\napp-package"]
    end

    style FA fill:#0078d4,color:#fff
    style STORAGE fill:#FFF3E0

flowchart LR
    A[Set variables + login] --> B[Create RG + storage]
    B --> C[Create deployment container]
    C --> D[Create function app]
    D --> E[Assign Storage Blob Data Contributor]
    E --> F[Set placeholder settings]
    F --> G["Build + publish from output dir"]
    G --> H[Validate endpoints]

Steps¶

export RG="rg-func-dotnet-flex-demo"
export APP_NAME="func-dnetflex-$(date +%m%d%H%M)"
export STORAGE_NAME="stdnetflex$(date +%m%d)"
export LOCATION="koreacentral"

az login
az account set --subscription "<subscription-id>"

Command/Parameter	Purpose
`RG`	Resource group name
`APP_NAME`	Unique name for the function app
`STORAGE_NAME`	Storage account for state and deployment
`az login`	Authenticates your CLI session
`--subscription`	Sets the target subscription context

Step 2 - Create resource group and storage account¶

az group create --name "$RG" --location "$LOCATION"

az storage account create \
  --name "$STORAGE_NAME" \
  --resource-group "$RG" \
  --location "$LOCATION" \
  --sku Standard_LRS \
  --kind StorageV2

Command/Parameter	Purpose
`az group create`	Creates the resource group container
`--kind StorageV2`	Required for Flex Consumption deployment features

Step 3 - Create the deployment container¶

az storage container create \
  --name app-package \
  --account-name "$STORAGE_NAME" \
  --auth-mode login

Command/Parameter	Purpose
`app-package`	Standard name for the deployment artifact container
`--auth-mode login`	Uses your Microsoft Entra identity for creation

Container must exist before function app creation

Flex Consumption requires a pre-existing blob container for deployment packages. If the container does not exist, az functionapp create fails with a ContainerNotFound error.

Step 4 - Create function app¶

az functionapp create \
  --name "$APP_NAME" \
  --resource-group "$RG" \
  --storage-account "$STORAGE_NAME" \
  --runtime dotnet-isolated \
  --runtime-version 8.0 \
  --flexconsumption-location "$LOCATION" \
  --deployment-storage-name "$STORAGE_NAME" \
  --deployment-storage-container-name app-package \
  --deployment-storage-auth-type SystemAssignedIdentity

Command/Parameter	Purpose
`--runtime dotnet-isolated`	Targets the isolated worker process
`--flexconsumption-location`	Identifies this as a Flex Consumption app
`--deployment-storage-auth-type`	Uses Managed Identity for secure artifact access

Flex Consumption vs Consumption CLI differences

Flex Consumption uses --flexconsumption-location instead of --consumption-plan-location. It also requires --deployment-storage-name, --deployment-storage-container-name, and --deployment-storage-auth-type parameters.

Auto-created Application Insights

az functionapp create automatically provisions an Application Insights resource and links it to the function app.

Step 5 - Assign Storage Blob Data Contributor role¶

The managed identity needs explicit permission to write deployment packages to blob storage:

PRINCIPAL_ID=$(az functionapp identity show \
  --name "$APP_NAME" \
  --resource-group "$RG" \
  --query principalId \
  --output tsv)

STORAGE_ID=$(az storage account show \
  --name "$STORAGE_NAME" \
  --resource-group "$RG" \
  --query id \
  --output tsv)

az role assignment create \
  --assignee "$PRINCIPAL_ID" \
  --role "Storage Blob Data Contributor" \
  --scope "$STORAGE_ID"

Command/Parameter	Purpose
`az functionapp identity show`	Retrieves the app's Managed Identity ID
`az role assignment create`	Grants the app permission to read its own code

Role propagation delay

Azure role assignments can take 1-2 minutes to propagate. If publishing fails with a 403 error immediately after assignment, wait and retry.

Step 6 - Set placeholder trigger settings¶

STORAGE_CONN=$(az storage account show-connection-string \
  --name "$STORAGE_NAME" \
  --resource-group "$RG" \
  --output tsv)

az functionapp config appsettings set \
  --name "$APP_NAME" \
  --resource-group "$RG" \
  --settings \
    "QueueStorage=$STORAGE_CONN" \
    "EventHubConnection=Endpoint=sb://placeholder.servicebus.windows.net/;SharedAccessKeyName=placeholder;SharedAccessKey=cGxhY2Vob2xkZXI=;EntityPath=placeholder"

Command/Parameter	Purpose
`az functionapp config appsettings set`	Configures environment variables

Placeholder settings prevent host crashes

The .NET reference app includes triggers for Queue, EventHub, Blob, and Timer. Use connection string format for EventHubConnection — the __fullyQualifiedNamespace format triggers DefaultAzureCredential which may not be configured for all services.

FUNCTIONS_WORKER_RUNTIME is platform-managed

On Flex Consumption, FUNCTIONS_WORKER_RUNTIME is set by the platform during az functionapp create. You cannot set it manually via app settings.

Step 7 - Create trigger resources¶

az storage queue create \
  --name "incoming-orders" \
  --account-name "$STORAGE_NAME" \
  --auth-mode login

az storage container create \
  --name "uploads" \
  --account-name "$STORAGE_NAME" \
  --auth-mode login

Command/Parameter	Purpose
`az storage queue create`	Creates the queue for order processing
`az storage container create`	Creates the blob container for uploads

Step 8 - Build and publish¶

cd apps/dotnet
dotnet publish --configuration Release --output ./publish

cd publish
func azure functionapp publish "$APP_NAME" --dotnet-isolated

Command/Parameter	Purpose
`dotnet publish`	Compiles the project and dependencies
`func azure functionapp publish`	Deploys the artifacts to Azure

Must publish from output directory with --dotnet-isolated flag

When publishing from the compiled output directory, Core Tools cannot detect the project language. Always pass --dotnet-isolated to specify the worker runtime explicitly. Without this flag, the publish may succeed but functions will not be indexed correctly.

Upload size

.NET isolated worker publish output is approximately 6.82 MB, larger than Java (~326 KB) because it includes ASP.NET Core runtime dependencies.

Step 9 - Validate deployment¶

# Wait for function indexing (may take 30-60 seconds)
sleep 30

# List deployed functions
az functionapp function list \
  --name "$APP_NAME" \
  --resource-group "$RG" \
  --query "[].{name:name, language:language}" \
  --output table

# Test the health endpoint
curl --request GET "https://$APP_NAME.azurewebsites.net/api/health"

# Test the hello endpoint
curl --request GET "https://$APP_NAME.azurewebsites.net/api/hello/FlexTest"

# Test the info endpoint
curl --request GET "https://$APP_NAME.azurewebsites.net/api/info"

Command/Parameter	Purpose
`az functionapp function list`	Lists all indexed functions in the app
`curl --request GET`	Sends validation requests to the app
`/api/health`	Probes service health state
`/api/info`	Inspects app configuration values

Step 10 - Review Flex Consumption-specific notes¶

Flex Consumption uses --flexconsumption-location instead of --consumption-plan-location.
Flex Consumption uses blob-based deployment storage, not Azure Files.
Managed identity is enabled by default — the /api/identity endpoint confirms this.
FUNCTIONS_WORKER_RUNTIME is platform-managed; do not set it manually.
Cold starts may be shorter than Consumption due to configurable instance memory.

Verification¶

Function list output (16 functions):

Name                                           Language
---------------------------------------------  ---------------
func-dnetflex-04100301/blobProcessor           dotnet-isolated
func-dnetflex-04100301/dnsResolve              dotnet-isolated
func-dnetflex-04100301/eventhubLagProcessor    dotnet-isolated
func-dnetflex-04100301/externalDependency      dotnet-isolated
func-dnetflex-04100301/health                  dotnet-isolated
func-dnetflex-04100301/helloHttp               dotnet-isolated
func-dnetflex-04100301/identityProbe           dotnet-isolated
func-dnetflex-04100301/info                    dotnet-isolated
func-dnetflex-04100301/logLevels               dotnet-isolated
func-dnetflex-04100301/queueProcessor          dotnet-isolated
func-dnetflex-04100301/scheduledCleanup        dotnet-isolated
func-dnetflex-04100301/slowResponse            dotnet-isolated
func-dnetflex-04100301/storageProbe            dotnet-isolated
func-dnetflex-04100301/testError               dotnet-isolated
func-dnetflex-04100301/timerLab                dotnet-isolated
func-dnetflex-04100301/unhandledError          dotnet-isolated

Health endpoint response:

{"status":"healthy","timestamp":"2026-04-10T03:11:06.477Z","version":"1.0.0"}

Hello endpoint response:

{"message":"Hello, FlexTest"}

Info endpoint response:

{"name":"azure-functions-dotnet-guide","version":"1.0.0","dotnet":".NET 8.0.23","os":"Linux","environment":"production","functionApp":"func-dnetflex-04100301"}

Identity probe (confirms managed identity is active on Flex Consumption):

{"managedIdentity":true,"identityEndpoint":"configured"}

Next Steps¶

Next: 03 - Configuration

02 - First Deploy (Flex Consumption)¶

Prerequisites¶

What You'll Build¶

Steps¶

Step 2 - Create resource group and storage account¶

Step 3 - Create the deployment container¶

Step 4 - Create function app¶

Step 5 - Assign Storage Blob Data Contributor role¶

Step 6 - Set placeholder trigger settings¶

Step 7 - Create trigger resources¶

Step 8 - Build and publish¶

Step 9 - Validate deployment¶

Step 10 - Review Flex Consumption-specific notes¶

Verification¶

Next Steps¶

See Also¶

Sources¶

02 - First Deploy (Flex Consumption)¶

Prerequisites¶

What You'll Build¶

Steps¶

Step 1 - Set variables and sign in¶

Step 2 - Create resource group and storage account¶

Step 3 - Create the deployment container¶

Step 4 - Create function app¶

Step 5 - Assign Storage Blob Data Contributor role¶

Step 6 - Set placeholder trigger settings¶

Step 7 - Create trigger resources¶

Step 8 - Build and publish¶

Step 9 - Validate deployment¶

Step 10 - Review Flex Consumption-specific notes¶

Verification¶

Next Steps¶

See Also¶

Sources¶