VIA-601 AJ/MD Update readme and minor rename refactor

Author: ankur-jain-nhs

infrastructure/README.md

@@ -37,7 +37,7 @@ The following secrets need to be created and set before running the application:
 
 ### Setting up Cloudfront error pages
 
-Manually create the following error routes.
+Manually create the following error routes. The current library we use doesn't update once created due to lifecycle rules, hence manual.
 
 - Go to AWS service "Cloudfront"
 - Select the distribution that serves VitA website (vaccinations.nhs.uk)
@@ -49,6 +49,12 @@ Manually create the following error routes.
   - Response page path: /service-failure
   - HTTP Response code: 500
 - Repeat the previous step for all other 5xx codes.
+- Click "Create custom error response" button
+    - HTTP error code: 403
+    - Error caching minimum TTL: 0
+    - Customise error response: yes
+    - Response page path: /assets/static/service-failure.html
+    - HTTP Response code: 403
 
 ### Setting default limits and settings
 

public/assets/static/service-failure.html

@@ -111,32 +111,33 @@ <h2 class="nhsuk-u-visually-hidden">Support links</h2>
       </div>
     </div>
   </footer>
+
   <script>
     function showComponentsBasedOnDevice() {
       window.onload = () => {
-        const handleClick = (event) => {
+        const handleBackLinkClick = (event) => {
           event.preventDefault();
           window.nhsapp.navigation.goToPage(window.nhsapp.navigation.AppPage.SERVICES);
         }
 
-        const handleSkipLink = (event) => {
+        const handleSkipLinkClick = (event) => {
           event.preventDefault();
           const contentTitle = document.getElementsByTagName("h1").item(0);
           contentTitle?.setAttribute("tabindex", "-1");
           contentTitle?.focus();
         }
 
         const skipLink = document.querySelector('.nhsuk-skip-link');
-        skipLink.addEventListener('click', handleSkipLink);
+        skipLink.addEventListener('click', handleSkipLinkClick);
 
         const guidance = document.getElementById('guidance');
         if (window.nhsapp.tools.isOpenInNHSApp()) {
           // mobile
           const backLink = document.querySelector('.nhsuk-back-link');
           backLink.style.display = 'block';
 
-          window.nhsapp.navigation.setBackAction(handleClick);
-          backLink.addEventListener('click', handleClick);
+          window.nhsapp.navigation.setBackAction(handleBackLinkClick);
+          backLink.addEventListener('click', handleBackLinkClick);
 
           guidance.innerHTML = 'Go back and try logging in again. If you cannot log in, try again later.';
         } else {