get-packer.sh

#!/bin/bash
###########################################################################
# Fetch and install the latest Packer version
# curl -Ls https://gist.githubusercontent.com/kitos9112/2252c54fff5bde6638b340fcade9076b/raw/777667f390965c6ad79e8b4e2a0c1a1ad70e2801/get-packer.sh  | bash
##########################################################################

function get_latest_github_release {
	curl -s https://api.github.com/repos/$1/$2/releases/latest | grep -oP '"tag_name": "[v]\K(.*)(?=")'
}

INSTALL_DIR='/usr/local/bin'
REGEX="^PATH=.*\K$INSTALL_DIR(?=.*)"
if [[ $(env | grep -oP $REGEX) != $INSTALL_DIR ]]; then 
   echo "Looks like your install directory $INSTALL_DIR is not in your PATH. Make sure you export it"; fi
   
INSTALLED_PACKER_VERSION=$(packer --version | grep -Poie '\d+.\d+.\d+')
LATEST_PACKER_RELEASE=$(get_latest_github_release hashicorp packer)

# Download and install Packer if there is a version mismatch
if [[ ${LATEST_PACKER_RELEASE} != ${INSTALLED_PACKER_VERSION} ]]; then
   echo "Installing Packer ${LATEST_PACKER_RELEASE}..."
   wget https://releases.hashicorp.com/packer/${LATEST_PACKER_RELEASE}/packer_${LATEST_PACKER_RELEASE}_linux_amd64.zip
   unzip -o packer_${LATEST_PACKER_RELEASE}_linux_amd64.zip
   rm packer_${LATEST_PACKER_RELEASE}_linux_amd64.zip
   sudo install packer ${INSTALL_DIR}/packer
   rm -rf packer
else
   echo "Nothing done. The Latest Packr version is already installed."
fi