tfvar

tfvar is a Terraform's variable definitions template generator. It scans your Terraform configurations or modules and extracts the variables into formats of your choice for editing, e.g., tfvar, environment variables, etc.

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

MacPorts (macOS)

sudo port install 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