Add healthcheck script and mechanism to make unhealthy if WP install integrity is compromised

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

@@ -16,6 +16,10 @@ function scriptExitHandler() {
   exit "${LAST_EXIT_CODE}"
 }
 
+function reportUnhealthy() {
+    echo "${1:?REASON is required}" > "/tmp/.wp-unhealthy"
+}
+
 # Main function
 function main() {
   # Removes trailing zero if found
@@ -28,8 +32,11 @@ function main() {
 
   set -e
 
+  rm -f "/tmp/.wp-unhealthy"
   if [ -z "${WP_INSTALLED_VERSION}" ]; then
     echo "> ERROR! WordPress installation does not seem to be present or valid. Continuing anyway..."
+
+    reportUnhealthy "WP_NOT_PRESENT"
     return 0
   elif [ "${WP_INSTALLED_VERSION}" != "${WP_VERSION}" ]; then
     echo "> WARNING! WordPress version mismatch"
@@ -39,6 +46,7 @@ function main() {
     echo "  - This is dangerous as changes will not persist when container is recreated which might lead to inconsistencies between installation and the database."
     echo "  - You should assume that recreating the container will render the website inoperable."
     echo "  - Please make sure that you're running image: nlss/wordpress:${WP_VERSION}"
+    reportUnhealthy "WP_VERSION_MISMATCH"
     return 0
   else
     echo "> Identified 'WordPress ${WP_VERSION}'"

rootfs/usr/local/bin/healthcheck

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+
+function main() {
+    FULL_CHECK="${1:-false}"
+
+    if [ -f "/tmp/.wp-unhealthy" ]; then
+        echo "Error: WordPress health is compromised: $(cat "/tmp/.wp-unhealthy")"
+        return 1
+    fi
+
+    # If FULL_CHECK is not requested, site functionality check with curl is skipped
+    if [ "${FULL_CHECK}" = "false" ]; then
+        return 0
+    fi
+
+    curl -sSf --output "/dev/null" "http://localhost/"
+    return $?
+}
+
+main "${@}"
+exit $?