Configuring Packer

This topic describes how to configure Packer. The default configurations are suitable for learning how to get started, but you should refer to this topic for guidance as you become more familiar with Packer.

Overview

You can set Packer-specific environment variables in a configuration file to configure Packer behavior globally. Install configuration files in the Packer configuration directory to implement the configurations. You can also install plugin files and their SHA256SUM files to the plugins subdirectory under the configuration directory. Refer to Installing Plugins for instructions.

You can also define Packer settings in a JSON configuration file and add it to the execution path. This configuration method is deprecated.

Install a configuration file

You can place internal configuration files into Packer's config directory. Packer checks the following paths for configuration files:

Examples

• Unix: If $PACKER_CONFIG_DIR is set to /home/packer, then the configuration directory is /home/packer/.packer.d/. Packer does not check other values.
• Windows: If PACKER_CONFIG_DIR is set to C:/, then the configuration directory is C:/packer.d/. Packer does not check other values.

Install a JSON configuration file

This installation method is deprecated since 1.7. Instead, use the HCL2 required_plugins block to configure how Packer installs plugins.

You use a JSON file to set core Packer settings. Packer checks the following paths for the configuration file:

JSON configuration file reference

Use basic JSON to configure the file. You can specify the configuration parameters for the core configuration file. All parameters are optional. None of these are required, since all have defaults.

• plugin_min_port: Number that specifies the lowest port that Packer can use for communicating with plugins. Packer communicates with plugins over TCP or Unix sockets on your local host. Default is 10000. We recommend setting a wide range between plugin_min_port and plugin_max_port so that Packer has access to at least 25 ports on a single run.
• plugin_max_port: Number that specifies highest port that Packer can for communicating with plugins. Packer communicates with plugins over TCP connections on your local Unix host. Default is 25000. We recommend setting a wide range between plugin_min_port and plugin_max_port so that Packer has access to at least 25 ports on a single run.

The packer init command takes precedence over JSON-configure settings when installing plugins.

Configure the cache directory

Packer uses a cache directory to download large files and for logistics around large file download. By default, Packer caches files in the .packer_cache folder of the current directory. Use the PACKER_CACHE_DIR environment variable to configure the cache directory. Refer to PACKER_CACHE_DIR for details.

We recommend using the same Packer cache directory across your builds if multiple builds perform similar actions. This is to avoid downloading the same large file, such as an ISO, multiple times.

Configuration reference

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_CONFIG_DIR - The location for the home directory of Packer. See 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 has rate-limits on its APIs. You can set the PACKER_GITHUB_API_TOKEN environment variable 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.

• PACKER_LOG_PATH - The location of the log file. Note: PACKER_LOG must be set for any logging to occur. See the debugging page.

• 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 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 for more.

• PACKER_PLUGIN_PATH - a PATH variable for finding packer plugins. This takes precedence over PACKER_CONFIG_DIR/plugins for plugin discovery if defined. Plugin installation requires access to temporary files under TMPDIR. If the system's temp directory is non-writable or non-executable, refer to TMPDIR to override the location of the temporary file store used by Packer.

• CHECKPOINT_DISABLE - When Packer is invoked it sometimes calls out to 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) - This specifies the directory for temporary files (defaulting to /tmp on Linux/Unix and %USERPROFILE%\AppData\Local\Temp on Windows Vista and later). Customizing this setting might be necessary for systems where the default temporary directory is either non-writable or non-executable.