diff --git a/containers/zammad/docker-entrypoint.sh b/containers/zammad/docker-entrypoint.sh
index 124e429..0a14ae8 100644
--- a/containers/zammad/docker-entrypoint.sh
+++ b/containers/zammad/docker-entrypoint.sh
@@ -30,22 +30,22 @@ function check_zammad_ready {
 # zammad init
 if [ "$1" = 'zammad-init' ]; then
   # install / update zammad
-  test -f ${ZAMMAD_READY_FILE} && rm ${ZAMMAD_READY_FILE}
-  rsync -a --delete --exclude 'public/assets/images/*' --exclude 'storage/fs/*' ${ZAMMAD_TMP_DIR}/ ${ZAMMAD_DIR}
-  rsync -a ${ZAMMAD_TMP_DIR}/public/assets/images/ ${ZAMMAD_DIR}/public/assets/images
+  test -f "${ZAMMAD_READY_FILE}" && rm "${ZAMMAD_READY_FILE}"
+  rsync -a --delete --exclude 'public/assets/images/*' --exclude 'storage/fs/*' "${ZAMMAD_TMP_DIR}/ ${ZAMMAD_DIR}"
+  rsync -a "${ZAMMAD_TMP_DIR}"/public/assets/images/ "${ZAMMAD_DIR}"/public/assets/images
 
-  until (echo > /dev/tcp/${POSTGRESQL_HOST}/${POSTGRESQL_PORT}) &> /dev/null; do
+  until (echo > /dev/tcp/"${POSTGRESQL_HOST}"/"${POSTGRESQL_PORT}") &> /dev/null; do
     echo "zammad railsserver waiting for postgresql server to be ready..."
     sleep 5
   done
 
-  cd ${ZAMMAD_DIR}
+  cd "${ZAMMAD_DIR}"
 
   # configure database
-  sed -e "s#.*adapter:.*#  adapter: postgresql#g" -e "s#.*database:.*#  database: ${POSTGRESQL_DB}#g" -e "s#.*username:.*#  username: ${POSTGRESQL_USER}#g" -e "s#.*password:.*#  password: ${POSTGRESQL_PASS}\n  host: ${POSTGRESQL_HOST}\n#g" < contrib/packager.io/database.yml.pkgr > config/database.yml
+  sed -e "s#.*adapter:.*#  adapter: postgresql#g" -e "s#.*database:.*#  database: ${POSTGRESQL_DB}#g" -e "s#.*username:.*#  username: ${POSTGRESQL_USER}#g" -e "s#.*password:.*#  password: ${POSTGRESQL_PASS}\\n  host: ${POSTGRESQL_HOST}\\n#g" < contrib/packager.io/database.yml.pkgr > config/database.yml
 
   # configure memcache
-  sed -i -e "s/.*config.cache_store.*file_store.*cache_file_store.*/    config.cache_store = :dalli_store, '${MEMCACHED_HOST}:${MEMCACHED_PORT}'\n    config.session_store = :dalli_store, '${MEMCACHED_HOST}:${MEMCACHED_PORT}'/" config/application.rb
+  sed -i -e "s/.*config.cache_store.*file_store.*cache_file_store.*/    config.cache_store = :dalli_store, '${MEMCACHED_HOST}:${MEMCACHED_PORT}'\\n    config.session_store = :dalli_store, '${MEMCACHED_HOST}:${MEMCACHED_PORT}'/" config/application.rb
 
   echo "initialising / updating database..."
 
@@ -62,7 +62,7 @@ if [ "$1" = 'zammad-init' ]; then
   set -e
 
   # create database if not exists
-  if [ "${DB_MIGRATE}" != "0" -a "${POSTGRESQL_DB_CREATE}" == "true" ]; then
+  if [ "${DB_MIGRATE}" != "0" ] && [ "${POSTGRESQL_DB_CREATE}" == "true" ]; then
       echo "creating database..."
       bundle exec rake db:create
   fi
@@ -91,17 +91,17 @@ if [ "$1" = 'zammad-init' ]; then
     sleep 5
   done
 
-  if [ -z "$(curl -s ${ELASTICSEARCH_HOST}:${ELASTICSEARCH_PORT}/_cat/indices | grep zammad)" ]; then
+  if curl -s ${ELASTICSEARCH_HOST}:${ELASTICSEARCH_PORT}/_cat/indices | grep -q zammad; then
     curl -s ${ELASTICSEARCH_HOST}:${ELASTICSEARCH_PORT}/_cat/indices
     echo "rebuilding es searchindex..."
     bundle exec rake searchindex:rebuild
   fi
 
   # chown everything to zammad user
-  chown -R ${ZAMMAD_USER}:${ZAMMAD_USER} ${ZAMMAD_DIR}
+  chown -R "${ZAMMAD_USER}":"${ZAMMAD_USER}" "${ZAMMAD_DIR}"
 
   # create install ready file
-  su -c "echo 'zammad-init' > ${ZAMMAD_READY_FILE}" ${ZAMMAD_USER}
+  su -c "echo 'zammad-init' > ${ZAMMAD_READY_FILE}" "${ZAMMAD_USER}"
 fi
 
 
@@ -110,7 +110,7 @@ if [ "$1" = 'zammad-nginx' ]; then
   check_zammad_ready
 
   # configure nginx
-  if [ -z "$(env|grep KUBERNETES)" ]; then
+  if env | grep -q KUBERNETES; then
     sed -e "s#server .*:3000#server ${ZAMMAD_RAILSSERVER_HOST}:${ZAMMAD_RAILSSERVER_PORT}#g" -e "s#server .*:6042#server ${ZAMMAD_WEBSOCKET_HOST}:${ZAMMAD_WEBSOCKET_PORT}#g" -e "s#server_name .*#server_name ${NGINX_SERVER_NAME};#g" -e 's#/var/log/nginx/zammad.\(access\|error\).log#/dev/stdout#g' < contrib/nginx/zammad.conf > /etc/nginx/sites-enabled/default
   fi
 
@@ -126,11 +126,11 @@ if [ "$1" = 'zammad-railsserver' ]; then
 
   check_zammad_ready
 
-  cd ${ZAMMAD_DIR}
+  cd "${ZAMMAD_DIR}"
 
   echo "starting railsserver..."
 
-  exec gosu ${ZAMMAD_USER}:${ZAMMAD_USER} bundle exec rails server puma -b [::] -p ${ZAMMAD_RAILSSERVER_PORT} -e ${RAILS_ENV}
+  exec gosu "${ZAMMAD_USER}":"${ZAMMAD_USER}" bundle exec rails server puma -b [::] -p "${ZAMMAD_RAILSSERVER_PORT}" -e "${RAILS_ENV}"
 fi
 
 
@@ -138,11 +138,11 @@ fi
 if [ "$1" = 'zammad-scheduler' ]; then
   check_zammad_ready
 
-  cd ${ZAMMAD_DIR}
+  cd "${ZAMMAD_DIR}"
 
   echo "starting scheduler..."
 
-  exec gosu ${ZAMMAD_USER}:${ZAMMAD_USER} bundle exec script/scheduler.rb run
+  exec gosu "${ZAMMAD_USER}":"${ZAMMAD_USER}" bundle exec script/scheduler.rb run
 fi
 
 
@@ -150,9 +150,9 @@ fi
 if [ "$1" = 'zammad-websocket' ]; then
   check_zammad_ready
 
-  cd ${ZAMMAD_DIR}
+  cd "${ZAMMAD_DIR}"
 
   echo "starting websocket server..."
 
-  exec gosu ${ZAMMAD_USER}:${ZAMMAD_USER} bundle exec script/websocket-server.rb -b 0.0.0.0 -p ${ZAMMAD_WEBSOCKET_PORT} start
+  exec gosu "${ZAMMAD_USER}":"${ZAMMAD_USER}" bundle exec script/websocket-server.rb -b 0.0.0.0 -p "${ZAMMAD_WEBSOCKET_PORT}" start
 fi