terraform/website/source/docs/configuration/environment-variables.html.md

---
layout: "docs"
page_title: "Environment Variables"
sidebar_current: "docs-config-environment-variables"
description: |-
  Terraform uses different environment variables that can be used to configure various aspects of how Terraform behaves. this section documents those variables, their potential values, and how to use them.
---

# Environment Variables

## TF_LOG

If set to any value, 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 empty. When unset, logging will default to stderr. For example:

```
export TF_LOG=
```

For more on debugging Terraform, check out the section on [Debugging](/docs/internals/debugging.html).

## 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 terraform from:

```
export TF_LOG_PATH=./terraform.log
```

For more on debugging Terraform, check out the section on [Debugging](/docs/internals/debugging.html).

## TF_INPUT

If set to "false" or "0", causes terraform 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_MODULE_DEPTH

When given a value, causes terraform commands to behave as if the `-module-depth=VALUE` flag was specified. By setting this to 0, for example, you enable commands such as [plan](/docs/commands/plan.html) and [graph](/docs/commands/graph.html) to display more compressed information.

```
export TF_MODULE_DEPTH=0
```

For more information regarding modules, check out the section on [Using Modules](/docs/modules/usage.html).

## 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
```

For more on how to use `TF_VAR_name` in context, check out the section on [Variable Configuration](/docs/configuration/variables.html).

## TF_SKIP_REMOTE_TESTS

This can be set prior to running the unit tests to opt-out of any tests
requiring remote network connectivity. The unit tests make an attempt to
automatically detect when connectivity is unavailable and skip the relevant
tests, but by setting this variable you can force these tests to be skipped.

```
export TF_SKIP_REMOTE_TESTS=1
make test
```