Add install etcd script

bin/install-etcd-system

@@ -0,0 +1,64 @@
+#!/usr/bin/env bash
+set -x
+
+set -e
+
+VERSION=${VERSION:-v3.4.4}
+
+PREFIX_DIR=/usr/local
+BIN_DIR=${PREFIX_DIR}/bin
+
+APP=etcd
+
+APP_PREFIX_DIR=${PREFIX_DIR}/${APP}
+APP_DEST_DIR=${APP_PREFIX_DIR}/${VERSION}
+APP_CURRENT=${APP_PREFIX_DIR}/current
+
+OS=
+if [[ $OSTYPE =~ linux ]]; then
+    OS=linux
+elif [[  $OSTYPE =~ darwin ]]; then
+    OS=darwin
+else
+    echo unknown os: $OSTYPE
+    exit 1
+fi
+
+ARCH=
+if [[ $(uname -m) == x86_64 ]]; then
+    ARCH=amd64
+else
+    echo arch not yet supported: $(uname -m)
+    exit 1
+fi
+URL=https://github.com/etcd-io/etcd/releases/download/${VERSION}/etcd-${VERSION}-${OS}-${ARCH}.tar.gz
+
+[[ -d ${APP_DEST_DIR} ]] || sudo mkdir -p ${APP_DEST_DIR}
+
+TMP_DIR=
+if [[ ! -d ${APP_DEST_DIR}/bin ]]; then
+    TMP_DIR=$(mktemp --directory)
+    DEST_FILE=$TMP_DIR/${APP}.tar.gz
+    echo downloading ${APP} ${VERSION} to temp directory ${TMP_DIR}
+    curl --silent --location --output ${DEST_FILE} ${URL}
+
+    sudo tar xf ${DEST_FILE} --directory ${APP_DEST_DIR} --strip-components 1
+    sudo chown --recursive root:root ${APP_DEST_DIR}
+else
+    echo ${APP} ${VERSION} already installed
+fi
+
+cd ${APP_PREFIX_DIR}
+[[ -s current ]] && sudo unlink current
+sudo ln --symbolic ${APP_DEST_DIR} current
+echo current version set to ${VERSION}
+
+cd ${BIN_DIR}
+for bin in $(find ${APP_CURRENT}/ -maxdepth 1 -executable -type f -exec basename {} \;); do
+    [[ -s $bin ]] || sudo ln --symbolic ${APP_CURRENT}/$bin
+done
+
+if [[ $TMP_DIR != "" ]]; then
+    rm -rf ${TMP_DIR}
+    echo removed up temp directory ${TMP_DIR}
+fi