---
description: |
  There are various ways to configure Packer. By default Packer will use known folders,
  which can be changed by using environment variables.
page_title: Configuring Packer
---

# Configuring Packer

-> **Note:** There are a few configuration settings that affect Packer globally
by configuring the core of Packer. These settings all have reasonable defaults,
so you generally don't have to worry about it until you want to tweak a
configuration. If you're just getting started with Packer, don't worry about
core configuration for now.

## Packer's home directory

Plugins and core configuration files can exist in the home directory of Packer.
The home directory of Packer will be the first one of the following env values
to be set :

| unix                   | windows               |
| ---------------------- | --------------------- |
| `${PACKER_CONFIG_DIR}` | `%PACKER_CONFIG_DIR%` |
| `${APPDATA}`           | `%APPDATA%`           |
| `${HOME}`              | `%HOME%`              |
| user dir of `${USER}`  | user dir of `${USER}` |

-> Note: On this page "Packer's home directory" will be referenced as
`PACKER_HOME_DIR`.

## Packer's config file

Packer can optionally read a JSON file for the end user to set core settings.
The config file of Packer will be looked up on the following paths:

| unix                            | windows                          |
| ------------------------------- | -------------------------------- |
| `${PACKER_CONFIG}`              | `%PACKER_CONFIG%`                |
| `PACKER_HOME_DIR/.packerconfig` | `PACKER_HOME_DIR/packer.config/` |

It is not an error if no config file was found.

## Packer's config directory

Packer's configuration directory can potentially contain plugins and internal
Packer files. The config dir of Packer will be looked up on the following paths:

| unix                        | windows                     |
| --------------------------- | --------------------------- |
| `PACKER_HOME_DIR/.packer.d` | `PACKER_HOME_DIR/packer.d/` |

Examples:

- On a 'unix' system, if the `$PACKER_CONFIG_DIR` env var is set to
  `/home/packer`, the config directory will be: `/home/packer/.packer.d/` and
  other values will not be checked.
- On a 'unix' system, if the `HOME` env var is `/home/azr` or the `USER` env var
  is `azr`, then the config directory will default to `/home/azr/.packer.d/`.
- On a 'windows' system, if the `PACKER_CONFIG_DIR` env var is set to `C:/`,the
  config directory will be: `C:/packer.d/` and other values will not be checked.

## Packer's plugin directory

@include "plugins/plugin-location.mdx"

The format of the configuration file is basic JSON.

## Packer's cache directory

Packer uses a cache directory to download large files and for logistics around
large file download. By default, Packer caches things in the current directory,
under: `./packer_cache/`. This can be changed by setting the `PACKER_CACHE_DIR`
env var. It is recommended to share the same Packer cache dir across your
builds if you have multiple builds doing similar things to avoid downloading the
same ISO twice for example.

## Packer config file configuration Reference

Below is the list of all available configuration parameters for the core
configuration file. None of these are required, since all have defaults.

- `plugin_min_port` and `plugin_max_port` (number) - These are the minimum
  and maximum ports that Packer uses for communication with plugins, since
  plugin communication happens over TCP connections on your local host. By
  default these are 10,000 and 25,000, respectively. Be sure to set a fairly
  wide range here, since Packer can easily use over 25 ports on a single run.

- `builders`, `commands`, `post-processors`, and `provisioners` are objects
  that are used to install plugins. The details of how exactly these are set is
  covered in more detail in the [installing plugins documentation
  page](/docs/extending/plugins). It is instead recommended to use [HCL2
  `required_plugins`](/docs/templates/hcl_templates/blocks/packer#specifying-plugin-requirements)
  and the [`packer init`](/docs/commands/init) command to install plugins; if
  you are using both, the `required_plugin` config will take precedence.

## Full list of Environment Variables usable for Packer

Packer uses a variety of environmental variables. A listing and description of
each can be found below:

- `PACKER_CACHE_DIR` - The location of the Packer cache. This defaults to
  `./packer_cache/`. Relative paths can be used. Some plugins can cache large
  files like ISOs in the cache dir.

- `PACKER_CONFIG` - The location of the core configuration file. The format
  of the configuration file is basic JSON. See [Packer's Config
  file](#packer-s-config-file).

- `PACKER_CONFIG_DIR` - The location for the home directory of Packer. See
  [Packer's home directory](#packer-s-home-directory) for more.

- `PACKER_GITHUB_API_TOKEN` - When using Packer init on HCL2 templates, Packer
  queries the public API from Github which limits the amount of queries on can
  set the `PACKER_GITHUB_API_TOKEN` with a Github Token to make it higher.

- `PACKER_LOG` - Setting this to any value other than "" (empty string) or
  "0" will enable the logger. See the [debugging
  page](/docs/other/debugging).

- `PACKER_LOG_PATH` - The location of the log file. Note: `PACKER_LOG` must
  be set for any logging to occur. See the [debugging
  page](/docs/other/debugging).

- `PACKER_NO_COLOR` - Setting this to any value will disable color in the
  terminal.

- `PACKER_PLUGIN_MAX_PORT` - The maximum port that Packer uses for
  communication with plugins, since plugin communication happens over TCP
  connections on your local host. The default is 25,000. This can also be set
  using the Packer's config file, see the [config file configuration
  reference](#packer-config-file-configuration-reference) for more.

- `PACKER_PLUGIN_MIN_PORT` - The minimum port that Packer uses for
  communication with plugins, since plugin communication happens over TCP
  connections on your local host. The default is 10,000. This can also be set
  using the Packer's config file, see the [config file configuration
  reference](#packer-config-file-configuration-reference) for more.

- `PACKER_PLUGIN_PATH` - a PATH variable for finding third-party packer
  plugins. For example: `~/custom-dir-1:~/custom-dir-2`. Separate directories in
  the PATH string using a colon (`:`) on posix systems and a semicolon (`;`) on
  windows systems. The above example path would be able to find a provisioner
  named `packer-provisioner-foo` in either
  `~/custom-dir-1/packer-provisioner-foo` or
  `~/custom-dir-2/packer-provisioner-foo`. See the documentation on [plugin
  directories](#packer-s-plugin-directory) for more.

- `CHECKPOINT_DISABLE` - When Packer is invoked it sometimes calls out to
  [checkpoint.hashicorp.com](https://checkpoint.hashicorp.com/) to look for
  new versions of Packer. If you want to disable this for security or privacy
  reasons, you can set this environment variable to `1`.

- `TMPDIR` (Unix) / `TMP` `TEMP` `USERPROFILE` (Windows) - The
  location of the directory used for temporary files (defaults to `/tmp` on
  Linux/Unix and `%USERPROFILE%\AppData\Local\Temp` on Windows Vista and above).
  It might be necessary to customize it when working with large files since
  `/tmp` is a memory-backed filesystem in some Linux distributions in which case
  `/var/tmp` might be preferred.
