Cleanup the code and use strict environment variables

rootfs/etc/cont-init.d/10-init-wordpress

@@ -1,15 +1,10 @@
 #!/usr/bin/with-contenv bash
-DISABLE_WP_UPDATES="${ENFORCE_DISABLE_WP_UPDATES:-true}"
-
 # Designed to replace original, overcomplicated entrypoint script from official wordpress docker repository
 # Why not use already available tools instead?!
 
-# Removes trailing zero if found
+# Applies patch for making WordPress updates impossible
-# This is required due to inconsistencies between WodPress docker image versioning and wp-cli core download
-# If patch version is 0, it is not considered by wp-cli.
-WP_VERSION=$(echo "${WP_VERSION}" | sed --expression='s/.0$//g');
-
 function disableUpdatesPatch() {
+  DISABLE_WP_UPDATES="${ENFORCE_DISABLE_WP_UPDATES:-true}"
   if [ "${DISABLE_WP_UPDATES}" != "false" ]; then
     echo "> Disabling WordPress updates..."
     patch /var/www/html/wp-admin/update-core.php </etc/wp-mods/wp-admin-update-core.patch
@@ -18,6 +13,7 @@ function disableUpdatesPatch() {
   fi
 }
 
+# Deletes known WordPress files
 function deleteWordPress() {
   echo "> Deleting WordPress installation (core files)"
 
@@ -27,9 +23,19 @@ function deleteWordPress() {
   rm -rf "/var/www/${WEB_ROOT}/"{.htaccess,index.php,license.txt,readme.html,wp-activate.php,wp-blog-header.php,wp-comments-post.php,wp-config-sample.php.php,wp-cron.php,wp-links-opml.php,wp-load.php,wp-login.php,wp-mail.php,wp-settings.php,wp-signup.php,wp-trackback.php,xmlrpc.php}
 }
 
+# Main function
+function main() {
+  # Removes trailing zero if found
+  # This is required due to inconsistencies between WodPress docker image versioning and wp-cli core download
+  # If patch version is 0, it is not considered by wp-cli.
+  WP_VERSION=$(echo "${WP_VERSION:?}" | sed --expression='s/.0$//g')
+  WP_LOCALE="${WP_LOCALE:?}"
+
   echo "> Verifying 'WordPress ${WP_VERSION}' installation..."
   WP_INSTALLED_VERSION="$(wp core version)"
 
+  set -e
+
   if [ -z "${WP_INSTALLED_VERSION}" ]; then
     echo "> WordPress is not present"
     echo "> Downloading 'WordPress ${WP_VERSION}'..."
@@ -48,3 +54,7 @@ elif [ "${WP_INSTALLED_VERSION}" != "${WP_VERSION}" ]; then
   else
     echo "> Identified 'WordPress ${WP_VERSION}'"
   fi
+}
+
+main "${@}"
+exit $?