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Shell Provisioner

Type: shell

The shell provisioner provisions machines built by Packer using shell scripts. Shell provisioning is the easiest way to get software installed and configured on a machine.

Basic Example

The example below is fully functional.

{
  "type": "shell",
  "inline": ["echo foo"]
}

Configuration Reference

The reference of available configuratin options is listed below. The only required element is either "inline" or "script". Every other option is optional.

Exactly one of the following is required:

• inline (array of strings) - This is an array of commands to execute. The commands are concatenated by newlines and turned into a single file, so they are all executed within the same context. This allows you to change directories in one command and use something in the directory in the next and so on. Inline scripts are the easiest way to pull of simple tasks within the machine.

• script (string) - The path to a script to upload and execute in the machine. This path can be absolute or relative. If it is relative, it is relative to the working directory when Packer is executed.

• scripts (array of strings) - An array of scripts to execute. The scripts will be uploaded and executed in the order specified. Each script is executed in isolation, so state such as variables from one script won't carry on to the next.

Optional parameters:

• environment_vars (array of strings) - An array of key/value pairs to inject prior to the execute_command. The format should be key=value.

• execute_command (string) - The command to use to execute the script. By default this is {{ .Vars }} sh {{ .Path }}. The value of this is treated as [configuration template](/docs/templates/configuration- templates.html). There are two available variables: Path, which is the path to the script to run, and Vars, which is the list of environment_vars, if configured.

• remote_path (string) - The path where the script will be uploaded to in the machine. This defaults to "/tmp/script.sh". This value must be a writable location and any parent directories must already exist.

Execute Command Example

To many new users, the execute_command is puzzling. However, it provides an important function: customization of how the command is executed. The most common use case for this is dealing with sudo password prompts.

For example, if the default user of an installed operating system is "packer" and has the password "packer" for sudo usage, then you'll likely want to change execute_command to be:

"echo 'packer' | sudo -S sh '{{ .Path }}'"

The -S flag tells sudo to read the password from stdin, which in this case is being piped in with the value of "packer".

By setting the execute_command to this, your script(s) can run with root privileges without worrying about password prompts.