install_golang.sh

#!/bin/bash

export install_dir="/usr/local/golang"

if [ -z $VERSION ]
then
    VERSION=$(curl -Ls https://go.dev/dl/?mode=json | jq -r '.[0].version')
    echo "No version specified, using latest version: $VERSION"
fi

if [ -d "$install_dir/$VERSION" ]
then
    echo "Go version $VERSION already installed"
    echo "Symlinks for Go binaries in $install_dir/bin/:"
    ls -l $install_dir/bin/
    exit 0
fi

OS="linux"
ARCH="amd64"

go_file_json=$(curl -Ls "https://go.dev/dl/?mode=json" \
    | VERSION="$VERSION" ARCH="$ARCH" OS="$OS" \
    jq '
    .[0].files[] 
        | select(.version | test(env.VERSION))
        | select(.os | test(env.OS))
        | select(.arch | test(env.ARCH))')

go_file_name=$(echo $go_file_json | jq -r '.filename')
echo "Downloading Go version $VERSION for $OS/$ARCH from $go_file_name"

tmp_dir=$(mktemp -d /tmp/go_install.XXXXXX)

echo "Downloading $go_file_name to $tmp_dir"
curl -s -Lo "$tmp_dir/$go_file_name" "https://go.dev/dl/$go_file_name"

echo "Checking checksum for $go_file_name"

go_file_sha256=$(echo $go_file_json | jq -r '.sha256')
shasum_res=$(echo "$go_file_sha256  $tmp_dir/$go_file_name" | sha256sum --check --status)

if [ ! $shasum_res ]; then
    echo "Checksum verified for $go_file_name"
else
    echo "Checksum verification failed for $go_file_name"
    exit 1
fi

echo "Extracting $go_file_name"

install_dir_version="$install_dir/$VERSION"

sudo mkdir -p -v "$install_dir_version"

sudo tar -C $install_dir/$VERSION -xzf "$tmp_dir/$go_file_name"

echo "Adding go path"

sudo mkdir -p -v $install_dir/bin

function set_go_bin_link() {
    echo "Creating symlink for $(basename $1) to $install_dir/bin/$(basename $1)"
    sudo ln -sf "$1" $install_dir/bin/$(basename $1)

}

export -f set_go_bin_link

find $install_dir/$VERSION/go/bin/ -type f -executable -exec bash -c "set_go_bin_link {}" \;

if [ -f ~/.bashrc ]; then
    echo "export GOROOT=$install_dir/$VERSION/go" >> ~/.bashrc
    echo "export GOPATH=$HOME/go" >> ~/.bashrc
    echo "export PATH=\$PATH:$install_dir/bin" >> ~/.bashrc
fi
if [ -f ~/.zshrc ]; then
    echo "export GOROOT=$install_dir/$VERSION/go" >> ~/.zshrc
    echo "export GOPATH=$HOME/go" >> ~/.zshrc
    echo "export PATH=\$PATH:$install_dir/bin" >> ~/.zshrc
fi

rm -rf "$tmp_dir"

echo "Go version $VERSION for $OS/$ARCH installed successfully"