Environment Variables

OpenTofu refers to a number of environment variables to customize various aspects of its behavior. None of these environment variables are required when using OpenTofu, but they can be used to change some of OpenTofu's default behaviors in unusual situations, or to increase output verbosity for debugging.

TF_LOG​

Enables detailed logs to appear on stderr which is useful for debugging. For example:

export TF_LOG=trace

To disable, either unset it, or set it to off. For example:

export TF_LOG=off

For more on debugging OpenTofu, check out the section on Debugging.

TF_LOG_PATH​

This specifies where the log should persist its output to. Note that even when TF_LOG_PATH is set, TF_LOG must be set in order for any logging to be enabled. For example, to always write the log to the directory you're currently running tofu from:

export TF_LOG_PATH=./terraform.log

For more on debugging OpenTofu, check out the section on Debugging.

TF_INPUT​

If set to "false" or "0", causes tofu commands to behave as if the -input=false flag was specified. This is used when you want to disable prompts for variables that haven't had their values specified. For example:

export TF_INPUT=0

TF_VAR_name​

Environment variables can be used to set variables. The environment variables must be in the format TF_VAR_name and this will be checked last for a value. For example:

export TF_VAR_region=us-west-1
export TF_VAR_ami=ami-049d8641
export TF_VAR_alist='[1,2,3]'
export TF_VAR_amap='{ foo = "bar", baz = "qux" }'

For more on how to use TF_VAR_name in context, check out the section on Variable Configuration.

TF_CLI_ARGS and TF_CLI_ARGS_name​

The value of TF_CLI_ARGS will specify additional arguments to the command-line. This allows easier automation in CI environments as well as modifying default behavior of OpenTofu on your own system.

These arguments are inserted directly after the subcommand (such as plan) and before any flags specified directly on the command-line. This behavior ensures that flags on the command-line take precedence over environment variables.

For example, the following command: TF_CLI_ARGS="-input=false" tofu apply -force is the equivalent to manually typing: tofu apply -input=false -force.

The flag TF_CLI_ARGS affects all OpenTofu commands. If you specify a named command in the form of TF_CLI_ARGS_name then it will only affect that command. As an example, to specify that only plans never refresh, you can set TF_CLI_ARGS_plan="-refresh=false".

The value of the flag is parsed as if you typed it directly to the shell. Double and single quotes are allowed to capture strings and arguments will be separated by spaces otherwise.

TF_DATA_DIR​

TF_DATA_DIR changes the location where OpenTofu keeps its per-working-directory data, such as the current backend configuration.

By default this data is written into a .terraform subdirectory of the current directory, but the path given in TF_DATA_DIR will be used instead if non-empty.

In most cases it should not be necessary to set this variable, but it may be useful to do so if e.g. the working directory is not writable.

The data directory is used to retain data that must persist from one command to the next, so it's important to have this variable set consistently throughout all of the OpenTofu workflow commands (starting with tofu init) or else OpenTofu may be unable to find providers, modules, and other artifacts.

TF_WORKSPACE​

For multi-environment deployment, in order to select a workspace, instead of doing tofu workspace select your_workspace, it is possible to use this environment variable. Using TF_WORKSPACE allow and override workspace selection.

For example:

export TF_WORKSPACE=your_workspace

Using this environment variable is recommended only for non-interactive usage, since in a local shell environment it can be easy to forget the variable is set and apply changes to the wrong state.

For more information regarding workspaces, check out the section on Using Workspaces.

TF_IN_AUTOMATION​

If TF_IN_AUTOMATION is set to any non-empty value, OpenTofu adjusts its output to avoid suggesting specific commands to run next. This can make the output more consistent and less confusing in workflows where users don't directly execute OpenTofu commands, like in CI systems or other wrapping applications.

This is a purely cosmetic change to OpenTofu's human-readable output, and the exact output differences can change between minor OpenTofu versions.

TF_REGISTRY_DISCOVERY_RETRY​

Set TF_REGISTRY_DISCOVERY_RETRY to configure the max number of request retries the remote registry client will attempt for client connection errors or 500-range responses that are safe to retry.

TF_REGISTRY_CLIENT_TIMEOUT​

The default client timeout for requests to the remote registry is 10s. TF_REGISTRY_CLIENT_TIMEOUT can be configured and increased during exceptional circumstances.

export TF_REGISTRY_CLIENT_TIMEOUT=15

TF_CLI_CONFIG_FILE​

The location of the OpenTofu CLI configuration file.

export TF_CLI_CONFIG_FILE="$HOME/.tofurc-custom"

TF_PLUGIN_CACHE_DIR​

The TF_PLUGIN_CACHE_DIR environment variable is an alternative way to set the plugin_cache_dir setting in the CLI configuration.

You can also use TF_PLUGIN_CACHE_MAY_BREAK_DEPENDENCY_LOCK_FILE to activate the transitional compatibility setting plugin_cache_may_break_dependency_lock_file.

TF_IGNORE​

If TF_IGNORE is set to "trace", OpenTofu will output debug messages to display ignored files and folders. This is useful when debugging large repositories with .terraformignore files.

export TF_IGNORE=trace

For more details on .terraformignore, please see Excluding Files from Upload with .terraformignore.

Cloud Backend CLI Integration​

The CLI integration with cloud backends lets you use them on the command line. The integration requires including a cloud block in your OpenTofu configuration. You can define its arguments directly in your configuration file or supply them through environment variables, which can be useful for non-interactive workflows like Continuous Integration (CI).

Refer to Cloud Backend Settings for a full list of cloud block environment variables.

TF_ENCRYPTION​

The TF_ENCRYPTION environment variable is an alternate method of specifying the contents of the terraform { encryption {} } block. If provided, it will be parsed as either HCL or JSON and override configuration present in the .tf config files.

# Add/Override encryption key_provider.static.mykp
export TF_ENCRYPTION='key_provider "static" "mykp" { key = "6f6f706830656f67686f6834616872756f3751756165686565796f6f72653169" }'