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Flex Consumption deprecated app settings

Rule ID: check_flex_deprecated_settings · Category: configuration · Section: runtime Severity: warning (non-gating) · Profiles: deploy, full · Tier: core

What it checks

For a Flex Consumption app, whether legacy app settings that Flex ignores are declared. Each flagged setting cites its replacement mechanism:

Deprecated setting Replacement
FUNCTIONS_WORKER_RUNTIME name under functionAppConfig.runtime
FUNCTIONS_WORKER_RUNTIME_VERSION version under functionAppConfig.runtime
FUNCTIONS_WORKER_PROCESS_COUNT Not valid on Flex; per-instance concurrency is platform-managed
SCM_DO_BUILD_DURING_DEPLOYMENT remoteBuild parameter when deploying to Flex
ENABLE_ORYX_BUILD remoteBuild parameter when deploying to Flex
WEBSITE_CONTENTSHARE functionAppConfig's deployment section
WEBSITE_CONTENTAZUREFILECONNECTIONSTRING functionAppConfig's deployment section
WEBSITE_RUN_FROM_PACKAGE and VNet route-all settings Site networking properties

linuxFxVersion and FUNCTIONS_EXTENSION_VERSION are owned by check_flex_runtime_config and check_functions_extension_version respectively, so this rule never emits a duplicate finding for them. Non-Flex apps skip.

Why it matters

Flex Consumption ignores a set of legacy app settings; leaving them in place is a configuration smell that masks the correct functionAppConfig-based configuration and can confuse deployments.

Symptoms

Deprecated app settings are silently ignored on Flex Consumption, so settings such as FUNCTIONS_WORKER_RUNTIME or WEBSITE_RUN_FROM_PACKAGE have no effect and hide the real configuration.

Example finding

Deprecated app settings declared on a Flex Consumption app:
  - FUNCTIONS_WORKER_RUNTIME: replaced by 'name' under functionAppConfig.runtime.
  - SCM_DO_BUILD_DURING_DEPLOYMENT: replaced by the remoteBuild parameter
    when deploying to Flex Consumption.
Flex Consumption ignores these settings; remove them and use the listed
replacement mechanism.

How to fix

Remove legacy app settings on Flex Consumption; configure the runtime, deployment, scaling, and networking through functionAppConfig and site networking properties instead.

Reference