github.com/iaas-resource-provision/iaas-rpc@v1.0.7-0.20211021023331-ed21f798c408/website/docs/cli/commands/validate.html.md

---
layout: "docs"
page_title: "Command: validate"
sidebar_current: "docs-commands-validate"
description: |-
  The `terraform validate` command is used to validate the syntax of the terraform files.
---

# Command: validate

The `terraform validate` command validates the configuration files in a
directory, referring only to the configuration and not accessing any remote
services such as remote state, provider APIs, etc.

Validate runs checks that verify whether a configuration is syntactically
valid and internally consistent, regardless of any provided variables or
existing state. It is thus primarily useful for general verification of
reusable modules, including correctness of attribute names and value types.

It is safe to run this command automatically, for example as a post-save
check in a text editor or as a test step for a re-usable module in a CI
system.

Validation requires an initialized working directory with any referenced
plugins and modules installed. To initialize a working directory for
validation without accessing any configured remote backend, use:

```
$ terraform init -backend=false
```

To verify configuration in the context of a particular run (a particular
target workspace, input variable values, etc), use the `terraform plan`
command instead, which includes an implied validation check.

## Usage

Usage: `terraform validate [options]`

This command accepts the following options:

- `-json` - Produce output in a machine-readable JSON format, suitable for
  use in text editor integrations and other automated systems. Always disables
  color.

- `-no-color` - If specified, output won't contain any color.

## JSON Output Format

When you use the `-json` option, Terraform will produce validation results
in JSON format to allow using the validation result for tool integrations, such
as highlighting errors in a text editor.

As with all JSON output options, it's possible that Terraform will encounter
an error prior to beginning the validation task that will thus not be subject
to the JSON output setting. For that reason, external software consuming
Terraform's output should be prepared to find data on stdout that _isn't_ valid
JSON, which it should then treat as a generic error case.

**Note:** The output includes a `format_version` key, which currently has major
version zero to indicate that the format is experimental and subject to change.
A future version will assign a non-zero major version and make stronger
promises about compatibility. We do not anticipate any significant breaking
changes to the format before its first major version, however.

In the normal case, Terraform will print a JSON object to the standard output
stream. The top-level JSON object will have the following properties:

* `valid` (boolean): Summarizes the overall validation result, by indicating
  `true` if Terraform considers the current configuration to be valid or
  `false` if it detected any errors.

* `error_count` (number): A zero or positive whole number giving the count
  of errors Terraform detected. If `valid` is `true` then `error_count` will
  always be zero, because it is the presence of errors that indicates that
  a configuration is invalid.

* `warning_count` (number): A zero or positive whole number giving the count
  of warnings Terraform detected. Warnings do not cause Terraform to consider
  a configuration to be invalid, but they do indicate potential caveats that
  a user should consider and possibly resolve.

* `diagnostics` (array of objects): A JSON array of nested objects that each
  describe an error or warning from Terraform.

The nested objects in `diagnostics` have the following properties:

* `severity` (string): A string keyword, currently either `"error"` or
  `"warning"`, indicating the diagnostic severity.

    The presence of errors causes Terraform to consider a configuration to be
    invalid, while warnings are just advice or caveats to the user which do not
    block working with the configuration. Later versions of Terraform may
    introduce new severity keywords, so consumers should be prepared to accept
    and ignore severity values they don't understand.

* `summary` (string): A short description of the nature of the problem that
  the diagnostic is reporting.

    In Terraform's usual human-oriented diagnostic messages, the summary serves
    as a sort of "heading" for the diagnostic, printed after the "Error:" or
    "Warning:" indicator.

    Summaries are typically short, single sentences, but can sometimes be longer
    as a result of returning errors from subsystems that are not designed to
    return full diagnostics, where the entire error message therefore becomes the
    summary. In those cases, the summary might include newline characters which
    a renderer should honor when presenting the message visually to a user.

* `detail` (string): An optional additional message giving more detail about
  the problem.

    In Terraform's usual human-oriented diagnostic messages, the detail provides
    the paragraphs of text that appear after the heading and the source location
    reference.

    Detail messages are often multiple paragraphs and possibly interspersed with
    non-paragraph lines, so tools which aim to present detail messages to the
    user should distinguish between lines without leading spaces, treating them
    as paragraphs, and lines with leading spaces, treating them as preformatted
    text. Renderers should then soft-wrap the paragraphs to fit the width of the
    rendering container, but leave the preformatted lines unwrapped.

    Some Terraform detail messages currently contain an approximation of bullet
    lists using ASCII characters to mark the bullets. This is not currently a
    contractural formatting convention and so renderers should avoid depending on
    it and should instead treat those lines as either paragraphs or preformatted
    text per the rules above. A future version of this format may define some
    additional rules for processing other text conventions, but will do so within
    the bounds of the rules above to achieve backward-compatibility.

* `range` (object): An optional object referencing a portion of the configuration
  source code that the diagnostic message relates to. For errors, this will
  typically indicate the bounds of the specific block header, attribute, or
  expression which was detected as invalid.

    A source range is an object with a property `filename` which gives the
    filename as a relative path from the current working directory, and then
    two properties `start` and `end` which are both themselves objects
    describing source positions, as described below.

    Not all diagnostic messages are connected with specific portions of the
    configuration, so `range` will be omitted or `null` for diagnostic messages
    where it isn't relevant.

* `snippet` (object): An optional object including an excerpt of the
  configuration source code that the diagnostic message relates to.

    The snippet information includes:

    * `context` (string): An optional summary of the root context of the
      diagnostic. For example, this might be the resource block containing the
      expression which triggered the diagnostic. For some diagnostics this
      information is not available, and then this property will be `null`.

    * `code` (string): A snippet of Terraform configuration including the
      source of the diagnostic. This can be multiple lines and may include
      additional configuration source code around the expression which
      triggered the diagnostic.

    * `start_line` (number): A one-based line count representing the position
      in the source file at which the `code` excerpt begins. This is not
      necessarily the same value as `range.start.line`, as it is possible for
      `code` to include one or more lines of context before the source of the
      diagnostic.

    * `highlight_start_offset` (number): A zero-based character offset into the
      `code` string, pointing at the start of the expression which triggered
      the diagnostic.

    * `highlight_end_offset` (number): A zero-based character offset into the
      `code` string, pointing at the end of the expression which triggered the
      diagnostic.

    * `values` (array of objects): Contains zero or more expression values
      which may be useful in understanding the source of a diagnostic in a
      complex expression. These expression value objects are described below.

### Source Position

A source position object, as used in the `range` property of a diagnostic
object, has the following properties:

* `byte` (number): A zero-based byte offset into the indicated file.

* `line` (number): A one-based line count for the line containing the relevant
  position in the indicated file.

* `column` (number): A one-based count of _Unicode characters_ from the start
  of the line indicated in `line`.

A `start` position is inclusive while an `end` position is exclusive. The
exact positions used for particular error messages are intended for human
interpretation only and subject to change in future versions of Terraform due
either to improvements to the error reporting or changes in implementation
details of the language parser/evaluator.

### Expression Value

An expression value object gives additional information about a value which is
part of the expression which triggered the diagnostic. This is especially
useful when using `for_each` or similar constructs, in order to identify
exactly which values are responsible for an error. The object has two properties:

* `traversal` (string): An HCL-like traversal string, such as
  `var.instance_count`. Complex index key values may be elided, so this will
  not always be valid, parseable HCL. The contents of this string are intended
  to be human-readable and are subject to change in future versions of
  Terraform.

* `statement` (string): A short English-language fragment describing the value
  of the expression when the diagnostic was triggered. The contents of this
  string are intended to be human-readable and are subject to change in future
  versions of Terraform.