bschaatsbergen / terraform-plugin-docs

Generate and validate Terraform plugin/provider documentation.

terraform-plugin-docs

This repository contains tools and packages for creating Terraform plugin docs (currently only provider plugins). The primary way users will interact with this is the tfplugindocs CLI tool to generate and validate plugin documentation.

tfplugindocs

The tfplugindocs CLI has two main commands, validate and generate (generate is the default). This tool will let you generate documentation for your provider from live example .tf files and markdown templates. It will also export schema information from the provider (using terraform providers schema -json), and sync the schema with the reference documents.

If your documentation only consists of simple examples and schema information, the tool can also generate missing template files to make website creation extremely simple for most providers.

Installation

You can install a copy of the binary manually from the releases, or you can optionally use the tools.go model for tool installation.

Usage

$ tfplugindocs --help
Usage: tfplugindocs [--version] [--help] <command> [<args>]

Available commands are:
                the generate command is run by default
    generate    generates a plugin website from code, templates, and examples
    validate    validates a plugin website for the current directory
       

generate command:

$ tfplugindocs generate --help

Usage: tfplugindocs generate [<args>]

    --examples-dir <ARG>             examples directory based on provider-dir                                                                                           (default: "examples")
    --ignore-deprecated <ARG>        don't generate documentation for deprecated resources and data-sources                                                             (default: "false")
    --provider-dir <ARG>             relative or absolute path to the root provider code directory when running the command outside the root provider code directory  
    --provider-name <ARG>            provider name, as used in Terraform configurations                                                                               
    --providers-schema <ARG>         path to the providers schema JSON file, which contains the output of the terraform providers schema -json command. Setting this flag will skip building the provider and calling Terraform CLI                                                                               
    --rendered-provider-name <ARG>   provider name, as generated in documentation (ex. page titles, ...)                                                              
    --rendered-website-dir <ARG>     output directory based on provider-dir                                                                                             (default: "docs")
    --tf-version <ARG>               terraform binary version to download                                                                                             
    --website-source-dir <ARG>       templates directory based on provider-dir                                                                                          (default: "templates")
    --website-temp-dir <ARG>         temporary directory (used during generation)  

validate command:

$ tfplugindocs validate --help

Usage: tfplugindocs validate [<args>]

How it Works

When you run tfplugindocs, by default from the root directory of a provider codebase, the tool takes the following actions:

• Copy all the templates and static files to a temporary directory
• Build (go build) a temporary binary of the provider source code
• Collect schema information using terraform providers schema -json
• Generate a default provider template file, if missing (index.md)
• Generate resource template files, if missing
• Generate data source template files, if missing
• Copy all non-template files to the output website directory
• Process all the remaining templates to generate files for the output website directory

For inspiration, you can look at the templates and output of the terraform-provider-random and terraform-provider-tls. You can browse their respective docs on the Terraform Registry, here and here.

About the id attribute

If the provider schema didn't set id for the given resource/data-source, the documentation generated will place it under the "Read Only" section and provide a simple description.

Otherwise, the provider developer can set an arbitrary description like this:

    // ...
    Schema: map[string]*schema.Schema{
        // ...
        "id": {
            Type:     schema.TypeString,
            Computed: true,
            Description: "Unique identifier for this resource",
		},
        // ...
    }
    // ...

Conventional Paths

The generation of missing documentation is based on a number of assumptions / conventional paths.

NOTE: In the following conventional paths, <data source name> and <resource name> include the provider prefix as well. For example, the data source caller_identity in the aws provider would have an "example" conventional path of: examples/data-sources/aws_caller_identity/data-source.tf

For templates:

Path	Description
templates/	Root of templated docs
templates/index.md[.tmpl]	Docs index page (or template)
templates/data-sources.md[.tmpl]	Generic data source page (or template)
templates/data-sources/<data source name>.md[.tmpl]	Data source page (or template)
templates/resources.md[.tmpl]	Generic resource page (or template)
templates/resources/<resource name>.md[.tmpl]	Resource page (or template)

Note: the .tmpl extension is necessary, for the file to be correctly handled as a template.

For examples:

Path	Description
examples/	Root of examples
examples/provider/provider.tf	Provider example config
examples/data-sources/<data source name>/data-source.tf	Data source example config
examples/resources/<resource name>/resource.tf	Resource example config
examples/resources/<resource name>/import.sh	Resource example import command

Templates

The templates are implemented with Go text/template using the following data fields and functions:

Data fields

Provider

Field	Type	Description
.Description	string	Provider description
.HasExample	bool	Is there an example file?
.ExampleFile	string	Path to the file with the terraform configuration example
.ProviderName	string	Canonical provider name (ex. terraform-provider-random)
.ProviderShortName	string	Short version of the provider name (ex. random)
.RenderedProviderName	string	Value provided via argument --rendered-provider-name, otherwise same as .ProviderName
.SchemaMarkdown	string	a Markdown formatted Provider Schema definition

Resources / Data Source

Field	Type	Description
.Name	string	Name of the resource/data-source (ex. tls_certificate)
.Type	string	Either Resource or Data Source
.Description	string	Resource / Data Source description
.HasExample	bool	Is there an example file?
.ExampleFile	string	Path to the file with the terraform configuration example
.HasImport	bool	Is there an import file?
.ImportFile	string	Path to the file with the command for importing the resource
.ProviderName	string	Canonical provider name (ex. terraform-provider-random)
.ProviderShortName	string	Short version of the provider name (ex. random)
.RenderedProviderName	string	Value provided via argument --rendered-provider-name, otherwise same as .ProviderName
.SchemaMarkdown	string	a Markdown formatted Resource / Data Source Schema definition

Functions

Function	Description
codefile	Create a Markdown code block with the content of a file. Path is relative to the repository root.
lower	Equivalent to strings.ToLower.
plainmarkdown	Render Markdown content as plaintext.
prefixlines	Add a prefix to all (newline-separated) lines in a string.
printf	Equivalent to fmt.Printf.
split	Split string into sub-strings, by a given separator (ex. split .Name "_").
title	Equivalent to cases.Title.
tffile	A special case of the codefile function, designed for Terraform files (i.e. .tf).
trimspace	Equivalent to strings.TrimSpace.
upper	Equivalent to strings.ToUpper.

Disclaimer

This is still under development: while it's being used for production-ready providers, you might still find bugs and limitations. In those cases, please report issues or, if you can, submit a pull-request.

Your help and patience is truly appreciated.

Contributing

License Headers

All source code files in this repository (excluding autogenerated files like go.mod, prose, and files excluded in .copywrite.hcl) must have a license header at the top.

This can be autogenerated by running make generate or running go generate ./... in the /tools directory.

Acceptance Tests

This repo uses the testscript package for acceptance testing.

There are two types of acceptance tests: full provider build tests in tfplugindocs/testdata/scripts/provider-build and provider schema json tests in tfplugindocs/testdata/scripts/schema-json.

Provider build tests run the default tfplugindocs command which builds the provider source code and runs Terraform to retrieve the schema. These tests require the full provider source code to build a valid provider binary.

Schema json tests run the tfplugindocs command with the --providers-schema=<arg> flag to specify a provider schemas json file. This allows the test to skip the provider build and Terraform CLI call, instead using the specified file to generate docs.

You can run make testacc to run the full suite of acceptance tests. By default, the provider build acceptance tests will create a temporary directory in /tmp/tftmp for testing, but you can change this location in cmd/tfplugindocs/main_test.go. The schema json tests uses the testscript package's default work directory.

The test scripts are defined in the tfplugindocs/testdata/scripts directory. Each script includes the test, golden files, and the provider source code or schema JSON file needed to run the test.

Each script is a text archive. You can install the txtar CLI locally by running go install golang.org/x/exp/cmd/txtar@latest to extract the files in the test script for debugging. You can also use txtar CLI archive files into the .txtar format to create new tests or modify existing ones.