diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..5ee4e38
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,17 @@
+# Copyright 2018 The Openstack-Helm Authors.
+#
+# 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
+#
+#     http://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.
+
+.PHONY: lint
+lint:
+	shellcheck assets/*.sh
diff --git a/assets/update_mirror_debian.sh b/assets/update_mirror_debian.sh
deleted file mode 100755
index 1523fe3..0000000
--- a/assets/update_mirror_debian.sh
+++ /dev/null
@@ -1,75 +0,0 @@
-#! /usr/bin/env bash
-set -e
-
-# Automate the initial creation and update of a Debian package mirror in aptly
-
-# The variables (as set below) will create a mirror of the Debian jessie repo 
-# with the main and update components. If you do mirror these, you'll want to
-# include "deb http://security.debian.org jessie/updates main" in your sources.list
-# file or mirror it similarly as done below to keep up with security updates.
-
-DEBIAN_RELEASE=stretch
-UPSTREAM_URL="http://deb.debian.org/debian/"
-COMPONENTS=( main )
-REPOS=( ${DEBIAN_RELEASE} ${DEBIAN_RELEASE}-updates )
-
-# Create repository mirrors if they don't exist
-set +e
-for component in ${COMPONENTS[@]}; do
-  for repo in ${REPOS[@]}; do
-    aptly mirror list -raw | grep "^${repo}$"
-    if [[ $? -ne 0 ]]; then
-      echo "Creating mirror of ${repo} repository."
-      aptly mirror create \
-        -architectures=amd64 ${repo} ${UPSTREAM_URL} ${repo} ${component}
-    fi
-  done
-done
-set -e
-
-# Update all repository mirrors
-for component in ${COMPONENTS[@]}; do
-  for repo in ${REPOS[@]}; do
-    echo "Updating ${repo} repository mirror.."
-    aptly mirror update ${repo}
-  done
-done
-
-# Create snapshots of updated repositories
-for component in ${COMPONENTS[@]}; do
-  for repo in ${REPOS[@]}; do
-    echo "Creating snapshot of ${repo} repository mirror.."
-    SNAPSHOTARRAY+="${repo}-`date +%Y%m%d%H` "
-    aptly snapshot create ${repo}-`date +%Y%m%d%H` from mirror ${repo}
-  done
-done
-
-echo ${SNAPSHOTARRAY[@]}
-
-# Merge snapshots into a single snapshot with updates applied
-echo "Merging snapshots into one.." 
-aptly snapshot merge -latest                 \
-  ${DEBIAN_RELEASE}-merged-`date +%Y%m%d%H`  \
-  ${SNAPSHOTARRAY[@]}
-
-# Publish the latest merged snapshot
-set +e
-aptly publish list -raw | awk '{print $2}' | grep "^${DEBIAN_RELEASE}$"
-if [[ $? -eq 0 ]]; then
-  aptly publish switch            \
-    -passphrase="${GPG_PASSWORD}" \
-    ${DEBIAN_RELEASE} ${DEBIAN_RELEASE}-merged-`date +%Y%m%d%H`
-else
-  aptly publish snapshot \
-    -passphrase="${GPG_PASSWORD}" \
-    -distribution=${DEBIAN_RELEASE} ${DEBIAN_RELEASE}-merged-`date +%Y%m%d%H`
-fi
-set -e
-
-# Export the GPG Public key
-if [[ ! -f /opt/aptly/public/aptly_repo_signing.key ]]; then
-  gpg --export --armor > /opt/aptly/public/aptly_repo_signing.key
-fi
-
-# Generate Aptly Graph
-aptly graph -output /opt/aptly/public/aptly_graph.png
diff --git a/assets/update_mirror_ubuntu.sh b/assets/update_mirror_ubuntu.sh
index 35787db..aa27bdf 100755
--- a/assets/update_mirror_ubuntu.sh
+++ b/assets/update_mirror_ubuntu.sh
@@ -16,65 +16,65 @@ if [ "$MODE" = "packages" ]; then
         echo "File with a package list is not found"
         exit 1
     fi
-    FILTER_OPTS=(-filter="$(cat /opt/packages/$PACKAGE_FILE | paste -sd \| -)" -filter-with-deps)
+    FILTER_VAL=$(paste -sd \| "/opt/packages/$PACKAGE_FILE")
+    FILTER_OPTS=("-filter=$FILTER_VAL" "-filter-with-deps")
 else
     FILTER_OPTS=()
 fi
 
+REPO_DATE=$(date +%Y%m%d%H)
+
 # Create repository mirrors if they don't exist
-set +e
 for component in ${COMPONENTS}; do
   for repo in ${REPOS}; do
-    aptly mirror list -raw | grep "^${repo}-${component}$"
-    if [[ $? -ne 0 ]]; then
+    if ! aptly mirror list -raw | grep "^${repo}-${component}$"
+    then
       echo "Creating mirror of ${repo}-${component} repository."
       aptly mirror create \
-        -architectures=amd64 "${FILTER_OPTS[@]}" ${repo}-${component} ${UPSTREAM_URL} ${repo} ${component}
+        -architectures=amd64 "${FILTER_OPTS[@]}" "${repo}-${component}" "${UPSTREAM_URL}" "${repo}" "${component}"
     fi
   done
 done
-set -e
 
 # Update all repository mirrors
 for component in ${COMPONENTS}; do
   for repo in ${REPOS}; do
     echo "Updating ${repo}-${component} repository mirror.."
-    aptly mirror update ${repo}-${component}
+    aptly mirror update "${repo}-${component}"
   done
 done
 
+SNAPSHOTARRAY=()
 # Create snapshots of updated repositories
 for component in ${COMPONENTS}; do
   for repo in ${REPOS}; do
     echo "Creating snapshot of ${repo}-${component} repository mirror.."
-    SNAPSHOTARRAY+="${repo}-${component}-`date +%Y%m%d%H` "
-    aptly snapshot create ${repo}-${component}-`date +%Y%m%d%H` from mirror ${repo}-${component}
+    SNAPSHOTARRAY+=("${repo}-${component}-$REPO_DATE")
+    aptly snapshot create "${repo}-${component}-$REPO_DATE" from mirror "${repo}-${component}"
   done
 done
 
-echo ${SNAPSHOTARRAY[@]}
+echo "${SNAPSHOTARRAY[@]}"
 
 # Merge snapshots into a single snapshot with updates applied
 echo "Merging snapshots into one.."
 aptly snapshot merge -latest                 \
-  ${UBUNTU_RELEASE}-merged-`date +%Y%m%d%H`  \
-  ${SNAPSHOTARRAY[@]}
+  "${UBUNTU_RELEASE}-merged-$REPO_DATE"  \
+  "${SNAPSHOTARRAY[@]}"
 
 # Publish the latest merged snapshot
-set +e
-aptly publish list -raw | awk '{print $2}' | grep "^${UBUNTU_RELEASE}$"
-if [[ $? -eq 0 ]]; then
+if aptly publish list -raw | awk '{print $2}' | grep "^${UBUNTU_RELEASE}$"
+then
   aptly publish switch            \
     -batch=true \
     -passphrase="${GPG_PASSWORD}" \
-    ${UBUNTU_RELEASE} ${UBUNTU_RELEASE}-merged-`date +%Y%m%d%H`
+    "${UBUNTU_RELEASE}" "${UBUNTU_RELEASE}-merged-$REPO_DATE"
 else
   aptly publish snapshot \
     -batch=true \
     -passphrase="${GPG_PASSWORD}" \
-    -distribution=${UBUNTU_RELEASE} ${UBUNTU_RELEASE}-merged-`date +%Y%m%d%H`
+    -distribution="${UBUNTU_RELEASE}" "${UBUNTU_RELEASE}-merged-$REPO_DATE"
 fi
-set -e
 
 # Export the GPG Public key
 if [[ ! -f /opt/aptly/public/aptly_repo_signing.key ]]; then