Drupal 8 automatic deployment git hook with changed config protection

post-receive

#!/bin/bash

# Script for automatic Drupal 8 deployment with checking current site configuration state.
# If site has any unexported configuration changes, the deployment is not executed.

GIT_DIR="path_to_repo.git"
TARGET="path_to_destination_dir"
BRANCH="production"

while read oldrev newrev ref
do
      # only checking out the specified branch you would like to deploy
      if [[ $ref = refs/heads/$BRANCH ]]; then
        # Check current config state.
        cd ${TARGET}
        CEX_EXPORT=$(drush cex --no |& grep identical)
        # Continue only if site config has no uncommitted changes.
        if [[ $CEX_EXPORT =~ "The active configuration is identical" ]]; then
	  # Deploy files.
          echo "Ref $ref received. Deploying ${BRANCH} branch to ${TARGET}..."
          git --git-dir=$GIT_DIR --work-tree=$TARGET checkout ${BRANCH} -f

          # Deployment command block starts HERE...
          cd ${TARGET}
          composer install --no-dev
#          cd ${TARGET}/web
          drush cr
          drush updb -y
          drush cim -y
          drush cr
	  # Deployment command block ends here.

          echo "Finished."
        else
          echo "WARNING! Site configuration has been changed. Deployment is stopped due to protect the changes."
          echo "  Export and commit configuration first or reset it with 'drush cim' manually."
          fi

        else
          echo "Ref $ref received. Only the ${BRANCH} branch may be deployed on this server."
        fi
done