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Yandex Cloud Functions
  • Comparison with other Yandex Cloud services
  • Getting started
    • Overview
    • Creating a function
      • Overview
      • Node.js
      • Python
      • Go
      • PHP
      • Bash
      • Java
    • Creating a trigger
      • Overview
      • Timer
      • Trigger for Message Queue
      • Trigger for Object Storage
      • Trigger for Container Registry
      • Trigger for Cloud Logs
      • Trigger for Cloud Logging
      • Trigger for Yandex IoT Core
      • Trigger for budgets
      • Trigger for Data Streams
  • Step-by-step instructions
    • All instructions
    • Using functions to get an IAM token for a service account
    • Connecting to managed databases from functions
    • Managing rights to access functions
    • Managing functions
      • Creating a function
      • Managing function versions
      • Working in the code editor
      • Invoking a function
      • Updating a function
      • Scaling a function
      • Function monitoring
      • Viewing the execution log
      • Deleting a function
    • Managing triggers
      • Getting information about a trigger
      • Creating a timer
      • Creating a trigger for Message Queue
      • Creating a trigger for Object Storage
      • Creating a trigger for Container Registry
      • Creating a trigger for Cloud Logs
      • Creating a trigger for Cloud Logging
      • Creating a trigger for Yandex IoT Core
      • Creating a trigger for budgets
      • Creating a trigger for Data Streams
      • Updating a trigger
      • Trigger monitoring
      • Deleting a trigger
  • Concepts
    • Overview
    • Function
    • Invoking a function
    • Runtime environment
      • Overview
      • Environment
      • Execution context
      • Preloaded runtime environment
    • Builder
    • Trigger
      • Overview
      • Timer
      • Trigger for Message Queue
      • Trigger for Object Storage
      • Trigger for Container Registry
      • Trigger for Cloud Logs
      • Trigger for Cloud Logging
      • Trigger for Yandex IoT Core
      • Trigger for budgets
      • Trigger for Data Streams
    • Dead Letter Queue
    • Log groups
    • Backups
    • Quotas and limits
  • Developing in Node.js
    • Overview
    • Managing dependencies
    • Request handler
    • Invocation context
    • Logging
    • Handling errors
    • Using the SDK
  • Developing in Python
    • Overview
    • Managing dependencies
    • Request handler
    • Invocation context
    • Logging
    • Handling errors
    • Using the SDK
  • Developing in Go
    • Overview
    • Managing dependencies
    • Request handler
    • Invocation context
    • Logging
    • Handling errors
    • Using the SDK
  • Developing in PHP
    • Overview
    • Managing dependencies
    • Request handler
    • Invocation context
    • Logging
    • Handling errors
  • Developing in Bash
    • Overview
    • Request handler
    • Logging
    • Handling errors
    • Using the SDK
  • Developing in Java
    • Overview
    • Programming model
      • Overview
      • Function interface
      • YcFunction interface
      • HttpServlet class
      • Spring Boot
    • Managing dependencies
    • Request handler
    • Invocation context
    • Logging
    • Handling errors
    • Using the SDK
  • Developing in R
    • Overview
    • Programming model
    • Managing dependencies
    • Request handler
    • Invocation context
    • Logging
    • Handling errors
  • Developing in C#
    • Overview
    • Programming model
      • Overview
      • Function interface
      • YcFunction interface
    • Managing dependencies
    • Request handler
    • Invocation context
    • Logging
    • Handling errors
    • Using the SDK
  • Practical guidelines
    • Creating skills for Alice
    • Deploying a web application
    • Developing a skill for Alice and a website with authorization
    • Writing data from a device to Managed Service for PostgreSQL
    • Developing a Slack bot
    • Developing a Telegram bot
    • Connecting to a YDB database from a Python function
    • Connecting to a YDB database from a function in Node.js
    • Converting a video to a GIF in Python
    • Creating a Node.js function using TypeScript
  • Pricing policy
  • Access management
  • API Functions reference
    • Authentication in the API
    • gRPC
      • Overview
      • FunctionService
      • OperationService
    • REST
      • Overview
      • Function
        • Overview
        • create
        • createVersion
        • delete
        • get
        • getVersion
        • getVersionByTag
        • list
        • listAccessBindings
        • listOperations
        • listRuntimes
        • listScalingPolicies
        • listTagHistory
        • listVersions
        • removeScalingPolicy
        • removeTag
        • setAccessBindings
        • setScalingPolicy
        • setTag
        • update
        • updateAccessBindings
  • API Triggers reference
    • Authentication in the API
    • gRPC
      • Overview
      • TriggerService
      • OperationService
    • REST
      • Overview
      • Trigger
        • Overview
        • create
        • delete
        • get
        • list
        • listOperations
        • pause
        • resume
        • update
  • Questions and answers
  1. Developing in Go
  2. Invocation context

Go function invocation context

Written by
Yandex Cloud

    Invocation context is an object that is optionally accepted by the request handler. The object type is context.Context. It provides an interface for getting more information about Go function version properties:

    • lambdaRuntimeFunctionName: The function ID (string).
    • lambdaRuntimeFunctionVersion: The function version ID (string).
    • lambdaRuntimeMemoryLimit: The amount of memory specified when creating the function version, MB (int).
    • lambdaRuntimeRequestID: The ID of the request being handled (string).

    To extract information from the invocation context, use its Value(key) method and pass it in the key parameter as a string with one of the keys described above.

    Authentication in the Yandex Cloud API

    If a function has a specified service account, you can use the SDK to obtain information that is necessary for authentication on behalf of this service account. To get this information, use the following methods:

    creds := ycsdk.InstanceServiceAccount()
    token, err := creds.IAMToken(ctx)
    

    The token.IamToken field contains the required IAM token.
    The code above works via the metadata service that is available in the function environment with the specified service account.

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