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terragrunt - GitHub

Configuration in Mega-Linter

Variable Description Default value
TERRAFORM_TERRAGRUNT_ARGUMENTS User custom arguments to add in linter CLI call
Ex: -s --foo "bar"
Ex: (src\|lib)
Include every file
Ex: (test\|examples)
Exclude no file
TERRAFORM_TERRAGRUNT_FILE_EXTENSIONS Allowed file extensions. "*" matches any extension, "" matches empty extension. Empty list excludes all files
Ex: [".py", ""]
TERRAFORM_TERRAGRUNT_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
TERRAFORM_TERRAGRUNT_CONFIG_FILE terragrunt configuration file name
Use LINTER_DEFAULT to let the linter find it
TERRAFORM_TERRAGRUNT_RULES_PATH Path where to find linter configuration file Workspace folder, then Mega-Linter default rules
TERRAFORM_TERRAGRUNT_DISABLE_ERRORS Run linter but consider errors as warnings false

Mega-Linter Flavours

This linter is available in the following flavours

Flavor Description Embedded linters Info
all Default Mega-Linter Flavor 91 Docker Image Size (tag) Docker Pulls
terraform Optimized for TERRAFORM based projects 43 Docker Image Size (tag) Docker Pulls

Behind the scenes

How are identified applicable files

  • File extensions: .hcl
  • File name do not ends with: .tflint.hcl

Example calls

terragrunt hclfmt --terragrunt-check --terragrunt-hclfmt-file myfile.hcl
terragrunt hclfmt --terragrunt-check --terragrunt-config terragrunt.hcl --terragrunt-hclfmt-file myfile.hcl

Help content

   terragrunt - Terragrunt is a thin wrapper for Terraform that provides extra tools for working with multiple
   Terraform modules, remote state, and locking. For documentation, see

   terragrunt <COMMAND> [GLOBAL OPTIONS]

   run-all               Run a terraform command against a 'stack' by running the specified command in each subfolder. E.g., to run 'terragrunt apply' in each subfolder, use 'terragrunt run-all apply'.
   terragrunt-info       Emits limited terragrunt state on stdout and exits
   validate-inputs       Checks if the terragrunt configured inputs align with the terraform defined variables.
   graph-dependencies    Prints the terragrunt dependency graph to stdout
   hclfmt                Recursively find hcl files and rewrite them into a canonical format.
   aws-provider-patch    Overwrite settings on nested AWS providers to work around a Terraform bug (issue #13018)
   *                     Terragrunt forwards all other commands directly to Terraform

   terragrunt-config                            Path to the Terragrunt config file. Default is terragrunt.hcl.
   terragrunt-tfpath                            Path to the Terraform binary. Default is terraform (on PATH).
   terragrunt-no-auto-init                      Don't automatically run 'terraform init' during other terragrunt commands. You must run 'terragrunt init' manually.
   terragrunt-no-auto-retry                     Don't automatically re-run command in case of transient errors.
   terragrunt-non-interactive                   Assume "yes" for all prompts.
   terragrunt-working-dir                       The path to the Terraform templates. Default is current directory.
   terragrunt-download-dir                      The path where to download Terraform code. Default is .terragrunt-cache in the working directory.
   terragrunt-source                            Download Terraform configurations from the specified source into a temporary folder, and run Terraform in that temporary folder.
   terragrunt-source-update                     Delete the contents of the temporary folder to clear out any old, cached source code before downloading new source code into it.
   terragrunt-iam-role                          Assume the specified IAM role before executing Terraform. Can also be set via the TERRAGRUNT_IAM_ROLE environment variable.
   terragrunt-iam-assume-role-duration          Session duration for IAM Assume Role session. Can also be set via the TERRAGRUNT_IAM_ASSUME_ROLE_DURATION environment variable.
   terragrunt-ignore-dependency-errors          *-all commands continue processing components even if a dependency fails.
   terragrunt-ignore-dependency-order           *-all commands will be run disregarding the dependencies
   terragrunt-ignore-external-dependencies      *-all commands will not attempt to include external dependencies
   terragrunt-include-external-dependencies     *-all commands will include external dependencies
   terragrunt-parallelism <N>                   *-all commands parallelism set to at most N modules
   terragrunt-exclude-dir                       Unix-style glob of directories to exclude when running *-all commands
   terragrunt-include-dir                       Unix-style glob of directories to include when running *-all commands
   terragrunt-check                             Enable check mode in the hclfmt command.
   terragrunt-hclfmt-file                       The path to a single hcl file that the hclfmt command should run on.
   terragrunt-override-attr                     A key=value attribute to override in a provider block as part of the aws-provider-patch command. May be specified multiple times.
   terragrunt-debug                             Write terragrunt-debug.tfvars to working folder to help root-cause issues.
   terragrunt-log-level                         Sets the logging level for Terragrunt. Supported levels: panic, fatal, error, warn (default), info, debug, trace.


   Gruntwork <>

Installation on mega-linter Docker image

  • Dockerfile commands :
FROM alpine/terragrunt:latest as terragrunt
COPY --from=terragrunt /usr/local/bin/terragrunt /usr/bin/

Example success log

Results of terragrunt linter (version 0.26.7)
See documentation on

[SUCCESS] .automation/test/terraform_terragrunt/terragrunt_good_1.hcl
    [terragrunt] 2020/12/05 12:35:50 Formatting terragrunt.hcl file at: .automation/test/terraform_terragrunt/terragrunt_good_1.hcl.
    [terragrunt] 2020/12/05 12:35:50 Formatting .automation/test/terraform_terragrunt/terragrunt_good_1.hcl

Example error log

Results of terragrunt linter (version 0.26.7)
See documentation on

[ERROR] .automation/test/terraform_terragrunt/terragrunt_bad_1.hcl
    [terragrunt] 2020/12/05 12:35:49 Formatting terragrunt.hcl file at: .automation/test/terraform_terragrunt/terragrunt_bad_1.hcl.
    [terragrunt] 2020/12/05 12:35:49 Formatting .automation/test/terraform_terragrunt/terragrunt_bad_1.hcl
    [terragrunt] 2020/12/05 12:35:49 Invalid file format .automation/test/terraform_terragrunt/terragrunt_bad_1.hcl
    [terragrunt] 2020/12/05 12:35:49 Unable to determine underlying exit code, so Terragrunt will exit with error code 1