source block

This topic providers reference information about the source block.

Description

The source block defines reusable builder configuration blocks. Builders are commonly used in custom plugins.

Example

The following example defines a source for a builder type called happycloud with the name foo:

# sources.pkr.hcl
source "happycloud" "foo" {
    // ...
}

There is only one source.happycloud.foo top-level source block, but it can be used more than once.

You can start builders by referring to source blocks from a build block :

build {
  sources = [
    # Here Packer will use a default ami_name when saving the image.
    "source.happycloud.example",
    "source.happycloud.foo",
  ]
}

The build-level source block allows to set specific source fields. Each field must be defined only once and it is currently not allowed to override a value.

build {
  source "source.happycloud.example" {
    # Here Packer will use the provided image_name instead of defaulting it.
    # Note that fields cannot be overwritten, in other words, you cannot
    # set the 'image_name' field in the top-level source block and here at the
    # same time
    image_name = "build_specific_field"
  }
}

Source Variables

Use the following syntax to access the name and type of your source from provisioners and post-processors:

<build-name>.<source-type>.<source-name>

The following example queries source names used in the build:

source "null" "first-example" {
  communicator = "none"
}

build {
  name = "roles"

  source "null.first-example" {
    name = "consul"
  }
  source "null.first-example" {
    name = "nomad"
  }
  source "null.first-example" {
    name = "vault"
  }
  sources = ["null.first-example"]

  provisioner "shell-local" {
    inline = ["echo ${source.name} and ${source.type}"]
  }
}

The example returns the following values:

• roles.null.consul: Returns consul and null
• roles.null.nomad: Returns nomad and null
• roles.null.vault: Returns vault and null
• roles.null.first-example: Returns first-example and null

Related

• The list of available builders can be found in the builders section.

• A list of community builders is available.

• Create your own custom builder !