AWS Lambda Audit a Function's Versions, Aliases, and Event Sources

arazzo: 1.0.1
info:
  title: AWS Lambda Audit a Function's Versions, Aliases, and Event Sources
  summary: Walk the account's functions, then drill into one to inventory its configuration, published versions, aliases, and attached event sources.
  description: >-
    A read-only sweep for governance, cost review, and incident triage. Nothing
    here mutates state, so it is safe to run against production on a schedule.
    The flow lists the account's functions in a region, then pivots to a single
    function and gathers the four facts an auditor actually needs: how it is
    configured right now, which immutable versions exist, which aliases point at
    which versions, and what event sources are invoking it. Together these answer
    what is deployed, what is reachable, and what is still triggering it. Every
    step spells out its request inline so the flow can be read and executed
    without opening the underlying OpenAPI description.
  version: 1.0.0
sourceDescriptions:
- name: lambdaApi
  url: ../openapi/aws-lambda-api-openapi.yml
  type: openapi
workflows:
- workflowId: function-inventory-audit
  summary: Inventory a function's configuration, versions, aliases, and event source mappings.
  description: >-
    Enumerates functions in the region, then reads the live configuration,
    published versions, alias-to-version bindings, and event source mappings for
    one named function.
  inputs:
    type: object
    required:
    - functionName
    properties:
      functionName:
        type: string
        description: The name or ARN of the function to audit in depth.
      maxItems:
        type: integer
        description: Maximum number of items returned per list call (1-10000).
  steps:
  - stepId: listAccountFunctions
    description: >-
      List the functions in the region to establish the account-level inventory
      the audited function sits in. FunctionVersion is left unset so the response
      carries the unpublished $LATEST configuration of each function rather than
      an entry per published version.
    operationId: listFunctions
    parameters:
    - name: MaxItems
      in: query
      value: $inputs.maxItems
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      functions: $response.body#/Functions
      nextMarker: $response.body#/NextMarker
  - stepId: auditConfiguration
    description: >-
      Read the live configuration of the audited function — runtime, role,
      memory, timeout, layers, and state. This is the $LATEST configuration,
      which is what the next published version will snapshot.
    operationId: getFunctionConfiguration
    parameters:
    - name: FunctionName
      in: path
      value: $inputs.functionName
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      functionArn: $response.body#/FunctionArn
      runtime: $response.body#/Runtime
      role: $response.body#/Role
      memorySize: $response.body#/MemorySize
      timeout: $response.body#/Timeout
      layers: $response.body#/Layers
      state: $response.body#/State
      lastModified: $response.body#/LastModified
      codeSha256: $response.body#/CodeSha256
  - stepId: auditVersions
    description: >-
      List the published versions. Each is an immutable snapshot of code and
      configuration, so this is the deployment history an auditor can roll back
      to.
    operationId: listVersionsByFunction
    parameters:
    - name: FunctionName
      in: path
      value: $inputs.functionName
    - name: MaxItems
      in: query
      value: $inputs.maxItems
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      versions: $response.body#/Versions
      nextMarker: $response.body#/NextMarker
  - stepId: auditAliases
    description: >-
      List the aliases and the versions they point at. This is what reveals which
      version is actually serving production traffic, and whether any alias is
      mid-canary with a weighted routing config.
    operationId: listAliases
    parameters:
    - name: FunctionName
      in: path
      value: $inputs.functionName
    - name: MaxItems
      in: query
      value: $inputs.maxItems
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      aliases: $response.body#/Aliases
  - stepId: auditEventSources
    description: >-
      List the event sources invoking this function, completing the picture of
      what can trigger it. LastProcessingResult on each mapping is the fastest
      signal that a source is failing.
    operationId: listEventSourceMappings
    parameters:
    - name: FunctionName
      in: query
      value: $inputs.functionName
    - name: MaxItems
      in: query
      value: $inputs.maxItems
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      eventSourceMappings: $response.body#/EventSourceMappings
  outputs:
    accountFunctions: $steps.listAccountFunctions.outputs.functions
    functionArn: $steps.auditConfiguration.outputs.functionArn
    runtime: $steps.auditConfiguration.outputs.runtime
    state: $steps.auditConfiguration.outputs.state
    versions: $steps.auditVersions.outputs.versions
    aliases: $steps.auditAliases.outputs.aliases
    eventSourceMappings: $steps.auditEventSources.outputs.eventSourceMappings