rootfs: Install yq if not found instead of error

When building rootfs, yq is needed to parse
the version from versions.yaml file. If yq
is not found, it fails. In this PR, we install
yq if not found.

Fixes: #363

Signed-off-by: Nitesh Konkar <niteshkonkar@in.ibm.com>

scripts/install-yq.sh

@@ -0,0 +1,72 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) 2019 IBM
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+# If we fail for any reason a message will be displayed
+die() {
+	msg="$*"
+	echo "ERROR: $msg" >&2
+	exit 1
+}
+
+# Install the yq yaml query package from the mikefarah github repo
+# Install via binary download, as we may not have golang installed at this point
+function install_yq() {
+	GOPATH=${GOPATH:-${HOME}/go}
+	local yq_path="${GOPATH}/bin/yq"
+	local yq_pkg="github.com/mikefarah/yq"
+	[ -x  "${GOPATH}/bin/yq" ] && return
+
+	read -r -a sysInfo <<< "$(uname -sm)"
+
+	case "${sysInfo[0]}" in
+	"Linux" | "Darwin")
+		goos="${sysInfo[0],}"
+		;;
+	"*")
+		die "OS ${sysInfo[0]} not supported"
+		;;
+	esac
+
+	case "${sysInfo[1]}" in
+	"aarch64")
+		goarch=arm64
+		;;
+	"ppc64le")
+		goarch=ppc64le
+		;;
+	"x86_64")
+		goarch=amd64
+		;;
+	"s390x")
+		goarch=s390x
+		;;
+	"*")
+		die "Arch ${sysInfo[1]} not supported"
+		;;
+	esac
+
+	mkdir -p "${GOPATH}/bin"
+
+	# Check curl
+	if ! command -v "curl" >/dev/null; then
+		die "Please install curl"
+	fi
+
+	local yq_version=2.3.0
+
+	local yq_url="https://${yq_pkg}/releases/download/${yq_version}/yq_${goos}_${goarch}"
+	curl -o "${yq_path}" -LSsf ${yq_url}
+	[ $? -ne 0 ] && die "Download ${yq_url} failed"
+	chmod +x ${yq_path}
+
+	if ! command -v "${yq_path}" >/dev/null; then
+		die "Cannot not get ${yq_path} executable"
+	fi
+}
+
+install_yq
+

scripts/lib.sh

@@ -12,6 +12,7 @@ GO_RUNTIME_PKG=${GO_RUNTIME_PKG:-github.com/kata-containers/runtime}
 # Give preference to variable set by CI
 KATA_BRANCH=${branch:-}
 KATA_BRANCH=${KATA_BRANCH:-master}
+yq_file="${script_dir}/../scripts/install-yq.sh"
 
 error()
 {
@@ -273,7 +274,9 @@ detect_go_version()
 {
 	info "Detecting agent go version"
 	typeset -r yq=$(command -v yq || command -v ${GOPATH}/bin/yq)
-	[ -z "$yq" ] && die "'yq' application not found (needed to parsing minimum Go version required)"
+	if [ -z "$yq" ]; then
+		source "$yq_file"
+	fi
 
 	local runtimeRevision=""