terraform/docs
Martin Atkins 6b4ed241d3 docs: Provider protocol wire format for values
Although we have in this same directory the protocol buffers schemas for
the static parts of the provider wire protocol, many of the protocol
messages include DynamicValue messages that are presented in a nested
dynamic serialization format.

That format was previously not documented, and was thus defined only by
the implementation. Terraform happens to use a third-party library to
implement parts of this encoding, which means that the rules were even
harder to track down from reading the code.

Regardless of how Terraform happens to implement its serialization and
deserialization of DynamicValue, it's the wire format that is contractual
and so this document is an implementation-agnostic description of the
mapping rules for serializing any Terraform Language value by reference to
a provider-defined schema.

All future changes to the rules described in here must be backward
compatible until protocol major version 6, which is not currently planned.
2020-09-01 10:40:36 -07:00
..
images make all unnecessary edges dotted 2020-07-02 14:22:52 -04:00
plugin-protocol docs: Provider protocol wire format for values 2020-09-01 10:40:36 -07:00
README.md docs: README for the plugin-protocol directory 2019-06-11 14:29:35 -07:00
architecture.md Fix spelling mistakes/typos in documentation 2020-07-22 18:24:32 +02:00
destroying.md make all unnecessary edges dotted 2020-07-02 14:22:52 -04:00
maintainer-etiquette.md Fix spelling mistakes/typos in documentation 2020-07-22 18:24:32 +02:00
resource-instance-change-lifecycle.md Fix spelling mistakes/typos in documentation 2020-07-22 18:24:32 +02:00

README.md

Terraform Core Codebase Documentation

This directory contains some documentation about the Terraform Core codebase, aimed at readers who are interested in making code contributions.

If you're looking for information on using Terraform, please instead refer to the main Terraform CLI documentation.

Terraform Core Architecture Documents

  • Terraform Core Architecture Summary: an overview of the main components of Terraform Core and how they interact. This is the best starting point if you are diving in to this codebase for the first time.

  • Resource Instance Change Lifecycle: a description of the steps in validating, planning, and applying a change to a resource instance, from the perspective of the provider plugin RPC operations. This may be useful for understanding the various expectations Terraform enforces about provider behavior, either if you intend to make changes to those behaviors or if you are implementing a new Terraform plugin SDK and so wish to conform to them.

    (If you are planning to write a new provider using the official SDK then please refer to the Extend documentation instead; it presents similar information from the perspective of the SDK API, rather than the plugin wire protocol.)

  • Plugin Protocol: gRPC/protobuf definitions for the plugin wire protocol and information about its versioning strategy.

    This documentation is for SDK developers, and is not necessary reading for those implementing a provider using the official SDK.

Contribution Guides

  • Maintainer Etiquette: guidelines and expectations for those who serve as Pull Request reviewers, issue triagers, etc.