Fix exit code handling in auto-renew function

The original code had a critical bug where exit codes from certificate
renewal failures were not properly captured due to bash subshell issues
with pipelines. When using a pipeline with '|', each command runs in a
subshell, so changes to variables inside the while loop don't persist
to the parent shell.

This fix:
- Replaces the pipeline approach with a temporary file to avoid subshell issues
- Properly captures and reports failures during certificate renewal
- Ensures that if any app fails to renew, the function will correctly
  report failure instead of always reporting success

This is particularly important for automated renewal processes where
proper error reporting is critical for monitoring and alerting.

Author: devopswithnaman

command-functions

@@ -38,19 +38,23 @@ cmd-letsencrypt-auto-renew() {
     # For all apps, sorted by ascending time left until renewal.
     # This way, we'll prioritize apps that need to be renewed soon
     # if we should hit a rate limit along the way.
-    fn-letsencrypt-list-apps-with-expiry \
-      | sort -nk5 \
-      | while IFS=$'\t' read -r -a appExpiry; do
-
-        if [[ ${appExpiry[4]} -lt 0 ]]; then
-          dokku_log_info1 "${appExpiry[0]} needs renewal"
-          dokku letsencrypt:enable "${appExpiry[0]}" || EXIT_CODE=$?
-        else
-          days_left=$(fn-letsencrypt-format-timediff "${appExpiry[4]}")
-          dokku_log_verbose "${appExpiry[0]} still has $days_left days left before renewal"
+    # Store the list in a temporary file to avoid subshell issues with pipelines
+    local temp_file=$(mktemp)
+    fn-letsencrypt-list-apps-with-expiry | sort -nk5 > "$temp_file"
+    
+    while IFS=$'\t' read -r -a appExpiry; do
+      if [[ ${appExpiry[4]} -lt 0 ]]; then
+        dokku_log_info1 "${appExpiry[0]} needs renewal"
+        if ! dokku letsencrypt:enable "${appExpiry[0]}"; then
+          EXIT_CODE=1
         fi
-
-      done
+      else
+        days_left=$(fn-letsencrypt-format-timediff "${appExpiry[4]}")
+        dokku_log_verbose "${appExpiry[0]} still has $days_left days left before renewal"
+      fi
+    done < "$temp_file"
+    
+    rm -f "$temp_file"
 
     dokku_log_info2 "Finished auto-renewal"
     if [[ "$EXIT_CODE" != 0 ]]; then