add --version option

Add a --version option as alternative to the $VERSION environment variable;

    ./install.sh --version 20.10
    # Executing docker install script, commit:
    + sh -c apt-get update -qq >/dev/null
    + sh -c DEBIAN_FRONTEND=noninteractive apt-get install -y -qq apt-transport-https ca-certificates curl gnupg >/dev/null
    debconf: delaying package configuration, since apt-utils is not installed
    + sh -c install -m 0755 -d /etc/apt/keyrings
    + sh -c curl -fsSL "https://download.docker.com/linux/ubuntu/gpg" | gpg --dearmor --yes -o /etc/apt/keyrings/docker.gpg
    + sh -c chmod a+r /etc/apt/keyrings/docker.gpg
    + sh -c echo "deb [arch=arm64 signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu jammy stable" > /etc/apt/sources.list.d/docker.list
    + sh -c apt-get update -qq >/dev/null
    INFO: Searching repository for VERSION '20.10'
    INFO: apt-cache madison docker-ce | grep '20.10' | head -1 | awk '{$1=$1};1' | cut -d' ' -f 3
    INFO: apt-cache madison docker-ce-cli | grep '20.10' | head -1 | awk '{$1=$1};1' | cut -d' ' -f 3
    + sh -c DEBIAN_FRONTEND=noninteractive apt-get install -y -qq docker-ce=5:20.10.24~3-0~ubuntu-jammy docker-ce-cli=5:20.10.24~3-0~ubuntu-jammy containerd.io docker-compose-plugin docker-ce-rootless-extras=5:20.10.24~3-0~ubuntu-jammy >/dev/null

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

install.sh

@@ -55,6 +55,10 @@ while [ $# -gt 0 ]; do
 			mirror="$2"
 			shift
 			;;
+		--version)
+			VERSION="${2#v}"
+			shift
+			;;
 		--*)
 			echo "Illegal option $1"
 			;;