Salt

Type: salt

The Salt Packer provisioner executes Salt's "masterless" or "local" mode on the guest operating system of the image that Packer is building. Salt state files that exist on the guest operating system are used to customize the image to meet a defined desired state. This means the Salt Minion package must be installed on the guest operating system. State files can be uploaded from your local build machine (the one running Packer) by this plugin. Salt is then invoked on the guest machine in masterless mode via the salt-call command.

Basic Example

The example below is fully functional.

HCL2

packer {
  required_plugins {
    salt = {
      version = ">= 0.1.2"
      source  = "github.com/mpoore/salt"
    }
  }
}

variable "topping" {
  type    = string
  default = "mushroom"
}

source "docker" "example" {
  image       = "mpoore/salt-example:latest"
  export_path = "packer_example"
  run_command = ["-d", "-i", "-t", "--entrypoint=/bin/bash", "{{.Image}}"]
}

build {
  sources = [
    "source.docker.example"
  ]

  provisioner "salt" {
    state_files      = [ "example.sls" ]
    environment_vars = [ "TOPPINGS=${ var.topping }" ]
  }
}

where example.sls contains

echo_toppings:
  cmd.run:
    - name: 'echo $TOPPINGS'

Configuration Reference

The reference of available configuration options is listed below.

Required (one, not both, of):

• state_files (array of strings) - The individual state files to be applied by Salt. These files must exist on your local system where Packer is executing. State files are applied in the order in which they appear in the state_files parameter.

• state_tree (array of strings) - A path to the complete Salt State Tree on your local system to be copied to the remote machine. The structure of the State Tree is flexible, however the use of this option assumes that a top.sls file is present at the top of the State Tree. The plugin assumes that Salt will evaluate the top.sls file and match expressions to determine which individual states should be applied. This action is referred to as a "highstate".

Optional:

• target_os (string) - The target OS that the workload is using. This value is used to determine whether a Windows or Linux OS is in use. If not specified, this value defaults to linux. Supported values for the selection are:

  linux - This denotes that the target runs a Linux or Unix operating system. windows - This denotes that the target runs a Windows operating system.

  Presently this option determines some of the defaults used by the provisioner.

• state_files ([]string) - The individual state files to be applied by Salt. These files must exist on your local system where Packer is executing. State files are applied in the order in which they appear in the parameter. This option is exclusive with state_tree.

• state_tree (string) - A path to the complete Salt State Tree on your local system to be copied to the remote machine as the staging_directory. The structure of the State Tree is flexible, however the use of this option assumes that a top.sls file is present at the top of the State Tree. The plugin assumes that Salt will evaluate the top.sls file and match expressions to determine which individual states should be applied. This action is referred to as a "highstate". This option is exclusive with state_files.

  For more details about states and highstates, refer to the Salt documentation.

• staging_directory (string) - The directory where files will be uploaded to on the target system. Packer requires write permissions in this directory. Default values are used if this option is not set. The default value used will depend on the value of target_os. The default for Linux systems is:

  /tmp/packer-provisioner-salt
  

  For Windows systems the default is:

  C:/Windows/Temp/packer-provisioner-salt
  

  Windows paths are recommended to be set using / as the delimiter owing to more conventional characters causing issues when this plugin is executed on a Linux system.

• clean (bool) - If set to true, the contents uploaded to the target system will be removed after applying Salt states. By default this is set to false.

• environment_vars ([]string) - A collection of environment variables that will be made available to the Salt process when it is executed. The intended purpose of this facility is to enable secrets or environment-specific information to be consumed when applying Salt states.

  For example:

  environment_vars = [ "SECRET_VALUE=${ var.build_secret }",
                       "CONFIG_VALUE=${ var.config_value }" ]
  

  This would expose the environment variables SECRET_VALUE and CONFIG_VALUE to the Salt process. These environment variables can then be consumed within Salt states, for example:

  {% set secret_value = salt['environ.get']('SECRET_VALUE', 'default_value') %}
  {% set config_value = salt['environ.get']('CONFIG_VALUE', 'default_value') %}
  # Echo config value
  echo config value:
  cmd.run:
   - name: echo {{ config_value }}
  

• env_var_format (string) - An advanced option used to customize the format of the environment_vars supplied to the Salt process. The default format for environment variables is:

  "VARNAME='VARVALUE' "
  

  Note: There is a trailing space in the default value that is required to separate environment varables from each other.

Parameters common to all provisioners:

• pause_before (duration) - Sleep for duration before execution.

• max_retries (int) - Max times the provisioner will retry in case of failure. Defaults to zero (0). Zero means an error will not be retried.

• only (array of string) - Only run the provisioner for listed builder(s) by name.

• override (object) - Override the builder with different settings for a specific builder, eg :

  In HCL2:

  source "null" "example1" {
    communicator = "none"
  }
  
  source "null" "example2" {
    communicator = "none"
  }
  
  build {
    sources = ["source.null.example1", "source.null.example2"]
    provisioner "shell-local" {
      inline = ["echo not overridden"]
      override = {
        example1 = {
          inline = ["echo yes overridden"]
        }
      }
    }
  }
  

  In JSON:

  {
    "builders": [
      {
        "type": "null",
        "name": "example1",
        "communicator": "none"
      },
      {
        "type": "null",
        "name": "example2",
        "communicator": "none"
      }
    ],
    "provisioners": [
      {
        "type": "shell-local",
        "inline": ["echo not overridden"],
        "override": {
          "example1": {
            "inline": ["echo yes overridden"]
          }
        }
      }
    ]
  }
  

• timeout (duration) - If the provisioner takes more than for example 1h10m1s or 10m to finish, the provisioner will timeout and fail.