packer-cn/website/source/docs/other/environmental-variables.html.md

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description: 'Packer uses a variety of environmental variables.'
layout: docs
page_title: Environmental Variables for Packer
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# Environmental Variables 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.

-   `PACKER_CONFIG` - The location of the core configuration file. The format of
    the configuration file is basic JSON. See the [core configuration
    page](/docs/other/core-configuration.html).

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

-   `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.html).

-   `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. See the [core
    configuration page](/docs/other/core-configuration.html).

-   `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. See the [core
    configuration page](/docs/other/core-configuration.html).

-   `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` (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.