A way of setting the terraform version dynamically

Written for zsh on macOS, although could easily be written for bash or other shells.

Make sure you haven't already got terraform on your $PATH. That is, running terraform should not work.

1. Save the terraform file to a directory in your $PATH, for example, /usr/local/bin
2. Make the file executable: chmod +x /usr/local/bin/terraform

Either:

a) Create a file in your project called .tf_version which contains only the version of terraform you want to use:

% echo -n "0.12.3" > .tf_version
% terraform --version
Terraform v0.12.3

b) Set the environment variable TFENV_VER (Note: overrides value from .tf_version file):

% TFENV_VER=0.11.0 terraform --version
Terraform v0.11.0

The following variables can be overridden with environment variables

TFENV_URL default: https://releases.hashicorp.com
TFENV_VER default: contents of .tf_version
TFENV_ARCH default: darwin_amd64

For a list of releases and architectures, visit https://releases.hashicorp.com/terraform/