Add script to dl and extract verible tarball

Change-Id: I3048d374cbdf0710b2928317ac9453fd947eae41

install-verible.sh

diff --git a/install-verible.sh b/install-verible.sh
new file mode 100755
index 0000000..9fc445a
--- /dev/null
+++ b/install-verible.sh
@@ -0,0 +1,63 @@
+#!/bin/bash
+#
+# Copyright 2022 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Install prebuilt verible linter/formatter
+
+function clean {
+  if [[ ! -f "${PREINSTALL_DIR}/${VERIBLE_TARBALL}" ]]; then
+    rm "${DOWNLOAD_DIR}/${VERIBLE_TARBALL}"
+    rmdir "${DOWNLOAD_DIR}"
+  fi
+}
+
+if [[ -z "${ROOTDIR}" ]]; then
+  echo "Source build/setup.sh first"
+  exit 1
+fi
+
+# TODO Check where this full name belongs (e.g. build folder?)
+VERIBLE_TARBALL="verible.tar.gz"
+
+trap clean EXIT
+
+# Used by the CI shodan docker image
+PREINSTALL_DIR=/usr/src
+
+if [[ -f "${PREINSTALL_DIR}/${VERIBLE_TARBALL}" ]]; then
+  echo "${VERIBLE_TARBALL} stored in the machine at ${PREINSTALL_DIR}"
+  DOWNLOAD_DIR="${PREINSTALL_DIR}"
+else
+  echo "Download ${VERIBLE_TARBALL} from GCS..."
+  DOWNLOAD_URL="https://storage.googleapis.com/shodan-public-artifacts/verible.tar.gz"
+  DOWNLOAD_DIR="${OUT}/tmp/verible"
+
+  if [[ ! -d "${DOWNLOAD_DIR}" ]]; then
+    mkdir -p "${DOWNLOAD_DIR}"
+  fi
+
+  wget -P "${DOWNLOAD_DIR}" "${DOWNLOAD_URL}"
+fi
+
+if [[ ! -d "${OUT}/host/verible" ]]; then
+  mkdir -p "${OUT}/host/verible"
+fi
+
+tar -C "${OUT}/host/verible" --strip-components 1 -xf "${DOWNLOAD_DIR}/${VERIBLE_TARBALL}"
+
+if [[ -d "${OUT}/host/verible/bin" ]]; then
+  echo "Verible binaries now available in ${OUT}/host/verible/bin"
+fi
+