tfvar

tfvar is a Terraform's variable definitions template generator.

For Terraform configuration that has input variables declared, e.g.,

variable "image_id" {
  type = string
}

variable "availability_zone_names" {
  type    = list(string)
  default = ["us-west-1a"]
}

variable "docker_ports" {
  type = list(object({
    internal = number
    external = number
    protocol = string
  }))
  default = [
    {
      internal = 8300
      external = 8300
      protocol = "tcp"
    }
  ]
}

• tfvar will search for all input variables and generate template that helps user populates those variables easily:

  $ tfvar .
  availability_zone_names = ["us-west-1a"]
  docker_ports            = [{ external = 8300, internal = 8300, protocol = "tcp" }]
  image_id                = null
  

• Note that default values are assigned to the definitions by default as shown above. Use the --ignore-default options to ignore the default values.

  $ tfvar . --ignore-default
  availability_zone_names = null
  docker_ports            = null
  image_id                = null
  

• tfvar also provides other output formats:

  • In environment variable formats with -e flag:

    $ tfvar . -e
    export TF_VAR_availability_zone_names='["us-west-1a"]'
    export TF_VAR_docker_ports='[{ external = 8300, internal = 8300, protocol = "tcp" }]'
    export TF_VAR_image_id=''
    

  • The -r, --resource flag outputs all variables as tfe_variable resource of Terraform Enterprise (tfe) provider.

  • The -w, --workspace flag outputs all variables in the payload format for the Workspace Variables API https://www.terraform.io/docs/cloud/api/workspace-variables.html#sample-payload which can used together with jq to filter variables by key name.

    $ tfvar -w . | jq '. | select(.data.attributes.key == "region")'
    {
      "data": {
        "type": "vars",
        "attributes": {
          "key": "region",
          "value": "",
          "description": "",
          "category": "terraform",
          "hcl": false,
          "sensitive": false
        }
      }
    }
    

• There is also --auto-assign option for those who wants the values from terraform.tfvars[.json], *.auto.tfvars[.json], and environment variables (TF_VAR_ followed by the name of a declared variable) to be assigned to the generated definitions automatically.

  $ export TF_VAR_availability_zone_names='["custom_zone"]'
  $ tfvar . --auto-assign
  availability_zone_names = ["custom_zone"]
  docker_ports            = [{ external = 8300, internal = 8300, protocol = "tcp" }]
  image_id                = null
  

• Like the terraform (plan|apply) CLI tool, individual vairables can also be specified via --var option.

  $ tfvar . --var=availability_zone_names='["custom_zone"]' --var=image_id=abc123
  availability_zone_names = ["custom_zone"]
  docker_ports            = [{ external = 8300, internal = 8300, protocol = "tcp" }]
  image_id                = "abc123"
  

• Variables in file can also be specified via --var-file option.

  $ cat my.tfvars
  image_id = "xyz"
  $ tfvar . --var-file my.tfvars
  availability_zone_names = ["us-west-1a"]
  docker_ports            = [{ external = 8300, internal = 8300, protocol = "tcp" }]
  image_id                = "xyz"
  

• Multiple files can be specified via providing more --var-file options, variables overrides as for terraform command.

  $ cat my.tfvars
  image_id = "xyz"
  
  $ cat other.tfvars
  image_id = "abc"
  
  $ tfvar . --var-file my.tfvars --var-file other.tfvars
  image_id = "abc"
  

For more info, checkout the --help page:

$ tfvar --help
Generate variable definitions template for Terraform module as
one would write it in variable definitions files (.tfvars).

Usage:
  tfvar [DIR] [flags]

Flags:
  -a, --auto-assign            Use values from environment variables TF_VAR_* and
                               variable definitions files e.g. terraform.tfvars[.json] *.auto.tfvars[.json]
  -d, --debug                  Print debug log on stderr
  -e, --env-var                Print output in export TF_VAR_image_id=ami-abc123 format
  -h, --help                   help for tfvar
      --ignore-default         Do not use defined default values
  -r, --resource               Print output in Terraform Enterprise (tfe) provider's tfe_variable resource format
      --var stringArray        Set a variable in the generated definitions.
                               This flag can be set multiple times.
      --var-file stringArray   Set variables from a file.
                               This flag can be set multiple times.
  -v, --version                version for tfvar
  -w, --workspace              Print output variables as payloads for Workspace Variables API

Installation

Homebrew (macOS)

brew install shihanng/tfvar/tfvar

Debian, Ubuntu

curl -sLO https://github.com/shihanng/tfvar/releases/latest/download/tfvar_linux_amd64.deb
dpkg -i tfvar_linux_amd64.deb

RedHat, CentOS

rpm -ivh https://github.com/shihanng/tfvar/releases/latest/download/tfvar_linux_amd64.rpm

Binaries

The release page contains binaries built for various platforms. Download the version matches your environment (e.g. linux_amd64) and place the binary in the executable $PATH e.g. /usr/local/bin:

curl -sL https://github.com/shihanng/tfvar/releases/latest/download/tfvar_linux_amd64.tar.gz | \
    tar xz -C /usr/local/bin/ tfvar

For Gophers

With Go already installed in your system, use go get

go get github.com/shihanng/tfvar

or clone this repo and make install

git clone https://github.com/shihanng/tfvar.git
cd tfvar
make install

Contributing

Want to add missing feature? Found bug 🐛? Pull requests and issues are welcome. For major changes, please open an issue first to discuss what you would like to change ❤️.

make lint
make test

should help with the idiomatic Go styles and unit-tests.

License

MIT