Fix: [AEA-4388] - delete old cname records (#1227)

## Summary

- Routine Change

### Details

- use new delete stacks script
- delete old cname records

---------

Co-authored-by: Kris Szlapa <kris.szlapa1@nhs.net>

.github/scripts/delete_stacks.sh

@@ -1,18 +1,39 @@
 #!/usr/bin/env bash
 
+# generic script for removing cloudformation stacks and old CNAME records where the pull request is closed
+
+# the name of the repo this is running in
+REPO_NAME=prescriptionsforpatients
+
+# regex used in jq command that parses the output from aws cloudformation list-stacks and just captures stacks we are interested in
+CAPTURE_REGEX="^pfp-pr-(\\d+)(-sandbox)?$"
+
+# regex that is used to get the pull request id from the cloud formation stack name
+# this is used in a replace command to replace the stack name so what is left is just the pull request id
+PULL_REQUEST_STACK_REGEX=pfp-pr-
+
+# this should be a query to get old CNAME records to delete
+CNAME_QUERY=pfp-pr-
+
+main() {
+  delete_cloudformation_stacks
+  delete_cname_records
+}
+
+delete_cloudformation_stacks() {
+  echo "checking cloudformation stacks"
+  echo
+  ACTIVE_STACKS=$(aws cloudformation list-stacks | jq -r --arg CAPTURE_REGEX "${CAPTURE_REGEX}" '.StackSummaries[] | select ( .StackStatus != "DELETE_COMPLETE" ) | select( .StackName | capture($CAPTURE_REGEX) ) | .StackName ')
 
-delete_stacks () {
-  ACTIVE_STACKS="$1"
   mapfile -t ACTIVE_STACKS_ARRAY <<< "$ACTIVE_STACKS"
+
   for i in "${ACTIVE_STACKS_ARRAY[@]}"
   do 
     echo "Checking if stack $i has open pull request"
-    PULL_REQUEST=${i//pfp-pr-/}
-    PULL_REQUEST=${PULL_REQUEST//pr-}
-    PULL_REQUEST=${PULL_REQUEST//sandbox-/}
+    PULL_REQUEST=${i//${PULL_REQUEST_STACK_REGEX}/}
     PULL_REQUEST=${PULL_REQUEST//-sandbox/}
     echo "Checking pull request id ${PULL_REQUEST}"
-    URL="https://api.github.com/repos/NHSDigital/prescriptionsforpatients/pulls/${PULL_REQUEST}"
+    URL="https://api.github.com/repos/NHSDigital/${REPO_NAME}/pulls/${PULL_REQUEST}"
     RESPONSE=$(curl "${URL}" 2>/dev/null)
     STATE=$(echo "${RESPONSE}" | jq -r .state)
     if [ "$STATE" == "closed" ]; then
@@ -26,9 +47,38 @@ delete_stacks () {
   done
 }
 
+delete_cname_records() {
+  HOSTED_ZONE_ID=$(aws route53 list-hosted-zones-by-name --dns-name dev.eps.national.nhs.uk. | jq -r ".HostedZones[0] | .Id")
+  CNAME_RECORDS=$(aws route53 list-resource-record-sets --hosted-zone-id "${HOSTED_ZONE_ID}" \
+    --query "ResourceRecordSets[?Type == 'CNAME' && contains(Name, '${CNAME_QUERY}')]" \
+    | jq -r " .[] | .Name")
+
+  mapfile -t CNAME_RECORDS_ARRAY <<< "$CNAME_RECORDS"
 
-ACTIVE_STACKS=$(aws cloudformation list-stacks | jq -r '.StackSummaries[] | select ( .StackStatus != "DELETE_COMPLETE" ) | select( .StackName | capture("^pfp-pr-(\\d+)(-sandbox)?$") ) | .StackName ')
-OLD_ACTIVE_STACKS=$(aws cloudformation list-stacks | jq -r '.StackSummaries[] | select ( .StackStatus != "DELETE_COMPLETE" ) | select( .StackName | capture("^pr-(sandbox-)?(\\d+)$") ) | .StackName ')
+  for i in "${CNAME_RECORDS_ARRAY[@]}"
+  do
+    echo "Checking if CNAME record $i has open pull request"
+
+    PULL_REQUEST=$(echo "$i" | grep -Po '(?<=-pr-)\d+')
+    echo "Checking pull request id ${PULL_REQUEST}"
+    URL="https://api.github.com/repos/NHSDigital/${REPO_NAME}/pulls/${PULL_REQUEST}"
+    RESPONSE=$(curl --url "${URL}" --header "Authorization: Bearer ${GITHUB_TOKEN}" 2>/dev/null)
+    STATE=$(echo "${RESPONSE}" | jq -r .state)
+    if [ "$STATE" == "closed" ]; then
+      echo "** going to delete CNAME record $i as state is ${STATE} **"
+      record_set=$(aws route53 list-resource-record-sets --hosted-zone-id "${HOSTED_ZONE_ID}" \
+        --query "ResourceRecordSets[?Name == '$i']" --output json | jq .[0])
+
+      jq -n --argjson record_set "${record_set}" \
+          '{Changes: [{Action: "DELETE", ResourceRecordSet: $record_set}]}' > /tmp/payload.json
+
+      aws route53 change-resource-record-sets --hosted-zone-id "${HOSTED_ZONE_ID}" --change-batch file:///tmp/payload.json
+
+      echo "CNAME record $i deleted"
+      else
+        echo "not going to delete CNAME record $i as state is ${STATE} **"
+      fi
+  done
+}
 
-delete_stacks "${ACTIVE_STACKS}"
-delete_stacks "${OLD_ACTIVE_STACKS}"
+main

.github/workflows/delete_old_cloudformation_stacks.yml

@@ -36,3 +36,5 @@ jobs:
         shell: bash
         working-directory: .github/scripts
         run: ./delete_stacks.sh
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}