Go Updater (go-updater.sh) - bash script that automatically downloads and installs the latest stable version of Golang

go-updater.sh

#!/bin/bash
#
# Checks if a new stable version of Go is available. If a new version is available, it will download and install it.

set -o pipefail

######################################
#             Constants              #
######################################
OS="linux"
ARCH="amd64"
GO_GIT_URL="https://go.googlesource.com/go"
GO_INSTALL_DIR="/usr/local"
DEPENDENCIES="git,tar,sed,sort,grep,cut,tail,wget"

function is_root() {
	if [ "$EUID" -ne 0 ]; then
		echo "Please run as root"
		exit 3
	fi
}

function dependency_check() {
	for dependency in $(echo $DEPENDENCIES | tr "," " "); do
		if ! command -v "$dependency" &>/dev/null; then
			echo "Dependency '$dependency' not found. Please install it and try again."
			exit 2
		fi
	done
}

function identify_latest_version() {
	latest_version=$(git ls-remote --tags $GO_GIT_URL 2>/dev/null |
		sed "s/\t/ /g" |
		cut -d ' ' -f 2 |
		grep -F "refs/tags/go" |
		sed "s/^.*\///g" |
		grep -vi rc |
		sort -V |
		tail -1) 2>/dev/null || exit 1
	echo "$latest_version" && return 0
}

function download_and_install() {
	# Download the latest version of Go
	download_url="https://go.dev/dl/$1.$OS-$ARCH.tar.gz"
	echo "Downloading Go version $latest_version..."
	wget -qO "/tmp/$1.$OS-$ARCH.tar.gz" "$download_url" 2>/dev/null
	if [[ $? != 0 ]]; then
		echo "error occurred downloading go from '$download_url'."
		exit 1
	fi

	echo "Installing Go version $latest_version..."
	# Remove the old existing Go installation
	rm -rf "$GO_INSTALL_DIR/go" 2>/dev/null

	# Install the latest version of Go
	tar -C "$GO_INSTALL_DIR" -xzf "/tmp/$1.$OS-$ARCH.tar.gz" 2>/dev/null
	if [[ $? != 0 ]]; then
		echo "error occurred extracting '/tmp/$1.$OS-$ARCH.tar.gz' to '$GO_INSTALL_DIR/go'."
		exit 1
	fi

	# fix permissions
	chmod a+x "$GO_INSTALL_DIR"/go/bin/*

	# cleaning up
	rm "/tmp/$1.$OS-$ARCH.tar.gz"

	if echo "$PATH" | grep -q "$GO_INSTALL_DIR/go/bin"; then
		echo "Go version $latest_version installed successfully."
	else
		echo -e "Go version $latest_version installed successfully.\nPlease add '$GO_INSTALL_DIR/go/bin' to your PATH."
	fi
}

is_root

dependency_check

latest_version=$(identify_latest_version) || exit 1

download_and_install $latest_version