variable¶

The variable block defines a variable which will be used in another blocks. The variables can be set from environment variables (J_VAR_name=value) or the command argument (--variables='["name=value"]').

Example¶

variable "disable_frontend" {
  type = "bool"
  default = false
}

process "frontend" {
  command  = "yarn start"
  tty      = true
  disabled = "${var.disable_frontend}"
}

Description¶

type (str | optional | default: undefined)

The type of the variable. Available types are ‘str’, ‘bool’, ‘int’, ‘float’, ‘list’ and ‘dict’.
default (object | optional | default: undefined)

The default value of the variable. If it is not defined, the value must be provided at runtime from an environment variable or the command-line argument.

If type is not provided, it will be inferred based on default. If default is not provided, it is assumed to be str.

Embedding Variables¶

The variable embedding can be used only in a string:

disabled = "${var.disable_frontend}" # OK

It cannot be used outside of a string even though the target attribute requires bool or int because it is not a valid HCL:

disabled = ${var.disable_frontend} # NG

In Jaffle, the following strings can be treated as boolean values:

'true' and '1' => true
'false' and '0' => false

disabled = false

Setting Variables¶

Your can set values to the variables from environment variables (J_VAR_name=value) or the command argument (--variables='["name=value"]').

Example: Setting true to disable_frontend from an environment variable:

$ J_VAR_disable_frontend=true jaffle start

Example: Setting true to disable_frontend from the command-line argument:

$ jaffle start --variables='["disable_frontend=true"]'