» Command: init

The terraform init command is used to initialize a working directory containing Terraform configuration files. This is the first command that should be run after writing a new Terraform configuration or cloning an existing one from version control. It is safe to run this command multiple times.

» Usage

Usage: terraform init [options] [DIR]

This command performs several different initialization steps in order to prepare a working directory for use. More details on these are in the sections below, but in most cases it is not necessary to worry about these individual steps.

This command is always safe to run multiple times, to bring the working directory up to date with changes in the configuration. Though subsequent runs may give errors, this command will never delete your existing configuration or state.

If no arguments are given, the configuration in the current working directory is initialized. It is recommended to run Terraform with the current working directory set to the root directory of the configuration, and omit the DIR argument.

» General Options

The following options apply to all of (or several of) the initialization steps:

  • -input=true Ask for input if necessary. If false, will error if input was required.

  • -lock=false Disable locking of state files during state-related operations.

  • -lock-timeout=<duration> Override the time Terraform will wait to acquire a state lock. The default is 0s (zero seconds), which causes immediate failure if the lock is already held by another process.

  • -no-color Disable color codes in the command output.

  • -upgrade Opt to upgrade modules and plugins as part of their respective installation steps. See the sections below for more details.

» Copy a Source Module

By default, terraform init assumes that the working directory already contains a configuration and will attempt to initialize that configuration.

Optionally, init can be run against an empty directory with the -from-module=MODULE-SOURCE option, in which case the given module will be copied into the target directory before any other initialization steps are run.

This special mode of operation supports two use-cases:

  • Given a version control source, it can serve as a shorthand for checking out a configuration from version control and then initializing the work directory for it.

  • If the source refers to an example configuration, it can be copied into a local directory to be used as a basis for a new configuration.

For routine use it is recommended to check out configuration from version control separately, using the version control system's own commands. This way it is possible to pass extra flags to the version control system when necessary, and to perform other preparation steps (such as configuration generation, or activating credentials) before running terraform init.

» Backend Initialization

During init, the root configuration directory is consulted for backend configuration and the chosen backend is initialized using the given configuration settings.

Re-running init with an already-initalized backend will update the working directory to use the new backend settings. Depending on what changed, this may result in interactive prompts to confirm migration of workspace states. The -force-copy option suppresses these prompts and answers "yes" to the migration questions. The -reconfigure option disregards any existing configuration, preventing migration of any existing state.

To skip backend configuration, use -backend=false. Note that some other init steps require an initialized backend, so it is recommended to use this flag only when the working directory was already previously initialized for a particular backend.

The -backend-config=... option can be used for partial backend configuration, in situations where the backend settings are dynamic or sensitive and so cannot be statically specified in the configuration file.

» Child Module Installation

During init, the configuration is searched for module blocks, and the source code for referenced modules is retrieved from the locations given in their source arguments.

Re-running init with modules already installed will install the sources for any modules that were added to configuration since the last init, but will not change any already-installed modules. Use -upgrade to override this behavior, updating all modules to the latest available source code.

To skip child module installation, use -get=false. Note that some other init steps can complete only when the module tree is complete, so it's recommended to use this flag only when the working directory was already previously initialized with its child modules.

» Plugin Installation

During init, Terraform searches the configuration for both direct and indirect references to providers and attempts to load the required plugins.

For providers distributed by HashiCorp, init will automatically download and install plugins if necessary. Plugins can also be manually installed in the user plugins directory, located at ~/.terraform.d/plugins on most operating systems and <APPLICATION DATA>\plugins on Windows.

For more information about configuring and installing providers, see Configuration: Providers.

On subsequent runs, init only installs providers without acceptable versions installed. (This includes newly added providers, and providers whose installed versions can't meet the current version constraints.) Use -upgrade if you want to update all providers to the newest acceptable version.

You can modify terraform init's plugin behavior with the following options:

  • -upgrade — Update all previously installed plugins to the newest version that complies with the configuration's version constraints. This option does not apply to manually installed plugins.
  • -get-plugins=false — Skips plugin installation. Terraform will use plugins installed in the user plugins directory, and any plugins already installed for the current working directory. If the installed plugins aren't sufficient for the configuration, init fails.
  • -plugin-dir=PATH — Skips plugin installation and loads plugins only from the specified directory. This ignores the user plugins directory and any plugins already installed in the current working directory. To restore the default behavior after using this option, run init again and pass an empty string to -plugin-dir.
  • -verify-plugins=false — Skips release signature validation when installing downloaded plugins (not recommended). Official plugin releases are digitally signed by HashiCorp, and Terraform verifies these signatures when automatically downloading plugins. This option disables that verification. (Terraform does not check signatures for manually installed plugins.)

» Running terraform init in automation

For teams that use Terraform as a key part of a change management and deployment pipeline, it can be desirable to orchestrate Terraform runs in some sort of automation in order to ensure consistency between runs, and provide other interesting features such as integration with version control hooks.

There are some special concerns when running init in such an environment, including optionally making plugins available locally to avoid repeated re-installation. For more information, see Running Terraform in Automation.