@@ -105,6 +105,14 @@ rpm_import_repository_key() {

 	rm -rf "$tmpdir"

 }

+semverParse() {

+	major="${1%%.*}"

+	minor="${1#$major.}"

+	minor="${minor%%.*}"

+	patch="${1#$major.$minor.}"

+	patch="${patch%%[-.]*}"

+}

+

 do_install() {

 	case "$(uname -m)" in

 		*64)

@@ -119,6 +127,21 @@ do_install() {

 	esac

 	if command_exists docker; then

+		version="$(docker -v | awk -F '[ ,]+' '{ print $3 }')"

+		MAJOR_W=1

+		MINOR_W=10

+

+		semverParse $version

+

+		shouldWarn=0

+		if [ $major -lt $MAJOR_W ]; then

+			shouldWarn=1

+		fi

+

+		if [ $major -le $MAJOR_W ] && [ $minor -lt $MINOR_W ]; then

+			shouldWarn=1

+		fi

+

 		cat >&2 <<-'EOF'

 			Warning: the "docker" command appears to already exist on this system.

@@ -127,7 +150,23 @@ do_install() {

 			installation.

 			If you installed the current Docker package using this script and are using it

+		EOF

+

+		if [ $shouldWarn -eq 1 ]; then

+			cat >&2 <<-'EOF'

+			again to update Docker, we urge you to migrate your image store before upgrading

+			to v1.10+.

+

+			You can find instructions for this here:

+			https://github.com/docker/docker/wiki/Engine-v1.10.0-content-addressability-migration

+			EOF

+		else

+			cat >&2 <<-'EOF'

 			again to update Docker, you can safely ignore this message.

+			EOF

+		fi

+

+		cat >&2 <<-'EOF'

 			You may press Ctrl+C now to abort this script.

 		EOF