| --- |
| page_title: 'Command: 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 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. |
| |
| The output includes a `format_version` key, which as of Terraform 1.1.0 has |
| value `"1.0"`. The semantics of this version are: |
| |
| * We will increment the minor version, e.g. `"1.1"`, for backward-compatible |
| changes or additions. Ignore any object properties with unrecognized names to |
| remain forward-compatible with future minor versions. |
| * We will increment the major version, e.g. `"2.0"`, for changes that are not |
| backward-compatible. Reject any input which reports an unsupported major |
| version. |
| |
| We will introduce new major versions only within the bounds of |
| [the Terraform 1.0 Compatibility Promises](/language/v1-compatibility-promises). |
| |
| 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, 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 contain an approximation of bullet |
| lists using ASCII characters to mark the bullets. This is not a |
| contractural formatting convention, so renderers should avoid depending on |
| it and should instead treat those lines as either paragraphs or preformatted |
| text. Future versions of this format may define additional rules for other text conventions, but will maintain 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. |
| |
| ### 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. |
| |
| - `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. |