Template `template`

The Template resource allows the processing of templates, outputing the result as a file.

Templating uses the Handlebars language which is Mustache template language can be found at the following location: Mustache templating language details

Properties

Name
source
Type
(string: "")
Required
required
Readonly
Description
Local path to the template source file
Local path
source = "myfile.txt"
HereDoc
source = <<-EOF My inline content EOF
Name
destination
Type
(string: "")
Required
required
Readonly
Description
The destination to write the processed template to.
Name
variables
Type
(map[string]interface: map[]{})
Required
Readonly
Description
Variables to use with the template, variables are available to be used within the template using the go template syntax.
variables = { data_dir = "/tmp" }
Given the above variables, these could be used within a template with the following convention.
data_dir = "{{data_dir}}"

In addition to the main properties, all resources have meta properties, such as the id of the resource. To see the list of these properties please see the Meta Properties section in the documentation /docs/resources/meta.

Examples

Template using HereDoc

The following example shows how the template can be embedded into the resource stanza using HereDoc syntax.

resource "template" "consul_config" {

  source = <<-EOF
  data_dir = "{{data_dir}}"
  log_level = "DEBUG"

  datacenter = "dc1"
  primary_datacenter = "dc1"

  server = true

  bootstrap_expect = 1
  ui = true

  bind_addr = "0.0.0.0"
  client_addr = "0.0.0.0"
  advertise_addr = "10.6.0.200"

  ports {
    grpc = 8502
  }

  connect {
    enabled = true
  }
  EOF

  destination = "./consul_config/consul.hcl"

  variables = {
    data_dir = "/tmp"
  }
}

The file produced from this example would look like the following

data_dir = "/tmp"
log_level = "DEBUG"

datacenter = "dc1"
primary_datacenter = "dc1"

server = true

bootstrap_expect = 1
ui = true

bind_addr = "0.0.0.0"
client_addr = "0.0.0.0"
advertise_addr = "10.6.0.200"

ports {
  grpc = 8502
}

connect {
  enabled = true
}

External Files

To leverage external files you can use the file function which loads a file returning a string. This example also shows how interpolation can be used to ensure a template is processed before it is consumed.

resource "template "consul_config" {

  source = file("./mytemplate.hcl") 
  destination = "./consul_config/consul.hcl"

  variables = {
    data_dir = "/tmp"
  }
}

container "consul" {
  depends_on = ["template.consul_config"]

  image   {
    name = "consul:${variable.consul_version}"
  }

  command = ["consul", "agent", "-config-file=/config/consul.hcl"]

  volume {
    source      = resource.template.consul_config.destination
    destination = "/config/consul.hcl"
  }
}

Inline variables

resource "template" "consul_config" {

  source = <<-EOF
  data_dir = "${data("test")}"
  log_level = "DEBUG"

  datacenter = "${variable.datacenter}"

  server = ${variable.server}
  EOF

  destination = "./consul_config/consul.hcl"

}

Template Functions

The template resource provides custom functions that can be used inside your templates as shown in the example below.

resource "template" "consul_config" {

  source = <<-EOF

  file_content = "{{ file "./myfile.txt" }}"
  quote = {{quote something}} 
  trim = {{quote (trim with_whitespace)}}

  EOF

  destination = "./consul_config/consul.hcl"
}

quote [string]

Returns the original string wrapped in quotations, quote can be used with the Go template pipe modifier.

// given the string abc

quote "abc" // would return the value "abc"

trim [string]

Removes whitespace such as carrige returns and spaces from the begining and the end of the string, can be used with the Go template pipe modifier.

// given the string abc

trim " abc " // would return the value "abc"

Template template

Template `template`