title	description
v8r configuration in MegaLinter	How to use v8r (configure, ignore files, ignore errors, help & version documentations) to analyze YAML files

v8r

v8r is a command-line validator for JSON, YAML, and TOML files that automatically detects and applies appropriate schemas from the Schema Store based on filename patterns, providing intelligent validation without manual schema configuration.

Key Features:

Automatic Schema Detection: Uses Schema Store to intelligently match files with appropriate schemas based on filename patterns
Multi-Format Support: Validates JSON, YAML, and TOML files with consistent interface across formats
Zero Configuration: Works out-of-the-box for common configuration files without requiring explicit schema specification
Schema Store Integration: Leverages the extensive collection of schemas from schemastore.org for popular tools and frameworks
Detailed Error Reporting: Provides clear, actionable validation error messages with line and column information

v8r documentation

Version in MegaLinter: 5.1.0
Visit Official Web Site{target=_blank}
See Index of problems detected by v8r{target=_blank}

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Configuration in MegaLinter

Enable v8r by adding YAML_V8R in ENABLE_LINTERS variable
Disable v8r by adding YAML_V8R in DISABLE_LINTERS variable

Variable	Description	Default value
YAML_V8R_ARGUMENTS	User custom arguments to add in linter CLI call Ex: `-s --foo "bar"`
YAML_V8R_COMMAND_REMOVE_ARGUMENTS	User custom arguments to remove from command line before calling the linter Ex: `-s --foo "bar"`
YAML_V8R_FILTER_REGEX_INCLUDE	Custom regex including filter Ex: `(src\|lib)`	Include every file
YAML_V8R_FILTER_REGEX_EXCLUDE	Custom regex excluding filter Ex: `(test\|examples)`	Exclude no file
YAML_V8R_CLI_LINT_MODE	Override default CLI lint mode - `file`: Calls the linter for each file - `list_of_files`: Call the linter with the list of files as argument - `project`: Call the linter from the root of the project	`list_of_files`
YAML_V8R_FILE_EXTENSIONS	Allowed file extensions. `"*"` matches any extension, `""` matches empty extension. Empty list excludes all files Ex: `[".py", ""]`	`[".yml", ".yaml"]`
YAML_V8R_FILE_NAMES_REGEX	File name regex filters. Regular expression list for filtering files by their base names using regex full match. Empty list includes all files Ex: `["Dockerfile(-.+)?", "Jenkinsfile"]`	Include every file
YAML_V8R_PRE_COMMANDS	List of bash commands to run before the linter	None
YAML_V8R_POST_COMMANDS	List of bash commands to run after the linter	None
YAML_V8R_UNSECURED_ENV_VARIABLES	List of env variables explicitly not filtered before calling YAML_V8R and its pre/post commands	None
YAML_V8R_CONFIG_FILE	v8r configuration file name Use `LINTER_DEFAULT` to let the linter find it	`.v8rrc.yml`
YAML_V8R_RULES_PATH	Path where to find linter configuration file	Workspace folder, then MegaLinter default rules
YAML_V8R_DISABLE_ERRORS	Run linter but consider errors as warnings	`false`
YAML_V8R_DISABLE_ERRORS_IF_LESS_THAN	Maximum number of errors allowed	`0`
YAML_V8R_CLI_EXECUTABLE	Override CLI executable	`['v8r']`

IDE Integration

Use v8r in your favorite IDE to catch errors before MegaLinter !

IDE	Extension Name	Install
Eclipse	native support	Visit Web Site{target=_blank}
IDEA	native support	Visit Web Site{target=_blank}
vim	vison	Visit Web Site{target=_blank}
Visual Studio Code	native support	Visit Web Site{target=_blank}

MegaLinter Flavors

This linter is available in the following flavors

Flavor	Description	Embedded linters
all	Default MegaLinter Flavor	126
c_cpp	Optimized for pure C/C++ projects	56
ci_light	Optimized for CI items (Dockerfile, Jenkinsfile, JSON/YAML schemas,XML	22
cupcake	MegaLinter for the most commonly used languages	87
documentation	MegaLinter for documentation projects	49
dotnet	Optimized for C, C++, C# or VB based projects	64
dotnetweb	Optimized for C, C++, C# or VB based projects with JS/TS	73
go	Optimized for GO based projects	51
java	Optimized for JAVA based projects	54
javascript	Optimized for JAVASCRIPT or TYPESCRIPT based projects	59
php	Optimized for PHP based projects	54
python	Optimized for PYTHON based projects	65
ruby	Optimized for RUBY based projects	50
rust	Optimized for RUST based projects	50
salesforce	Optimized for Salesforce based projects	54
swift	Optimized for SWIFT based projects	50
terraform	Optimized for TERRAFORM based projects	54

Behind the scenes

How are identified applicable files

File extensions: .yml, .yaml

How the linting is performed

v8r is called once with the list of files as arguments (list_of_files CLI lint mode)

Example calls

v8r --ignore-errors myfile.yml

v8r --ignore-errors myfile.yaml

Help content

ℹ No config file found
v8r <patterns..>

Validate local json/json5/toml/yaml files against schema(s)

Positionals:
  patterns  One or more filenames or glob patterns describing local file or
            files to validate

Options:
      --help                  Show help                                [boolean]
      --version               Show version number                      [boolean]
  -v, --verbose               Run with verbose logging. Can be stacked e.g: -vv
                              -vvv                                       [count]
  -s, --schema                Local path or URL of a schema to validate against.
                              If not supplied, we will attempt to find an
                              appropriate schema on schemastore.org using the
                              filename. If passed with glob pattern(s) matching
                              multiple files, all matching files will be
                              validated against this schema             [string]
  -c, --catalogs              A list of local paths or URLs of custom catalogs
                              to use prior to schemastore.org            [array]
      --ignore-errors         Exit with code 0 even if an error was encountered.
                              Passing this flag means a non-zero exit code is
                              only issued if validation could be completed
                              successfully and one or more files were invalid
                                                      [boolean] [default: false]
      --ignore-pattern-files  A list of files containing glob patterns to ignore
                                  [array] [default: [".v8rignore",".gitignore"]]
      --no-ignore             Disable all ignore files                 [boolean]
      --cache-ttl             Remove cached HTTP responses older than
                              <cache-ttl> seconds old. Passing 0 clears and
                              disables cache completely  [number] [default: 600]
      --output-format         Output format for validation results
                            [string] [choices: "text", "json"] [default: "text"]

Examples:
  v8r file.json                 Validate a single file
  v8r file1.json file2.json     Validate multiple files
  v8r 'dir/*.yml' 'dir/*.yaml'  Specify files to validate with glob patterns

Installation on mega-linter Docker image

Dockerfile commands :

# renovate: datasource=npm depName=v8r
ARG NPM_V8R_VERSION=5.1.0

NPM packages (node.js):
- v8r@5.1.0

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