diff --git a/docker/headscale/start.sh b/docker/headscale/start.sh
index 918b714..4d39d03 100644
--- a/docker/headscale/start.sh
+++ b/docker/headscale/start.sh
@@ -17,21 +17,18 @@ replace_config_values() {
     fi
 
     # Read the template and replace variables
-    local temp_file=$(mktemp)
-    cp "$config_template" "$temp_file"
-    while read -r line; do
-        while [[ "$line" =~ (\$\{[a-zA-Z_][a-zA-Z_0-9]*\}) ]]; do
-            LHS=${BASH_REMATCH[1]}
-            RHS="$(eval echo "\"$LHS\"")"
-            line=${line//$LHS/$RHS}
+    while IFS= read -r line || [[ -n "$line" ]]; do
+        while [[ "$line" =~ \$\{([a-zA-Z_][a-zA-Z_0-9]*)\} ]]; do
+            var_name=${BASH_REMATCH[1]}
+            var_value=$(eval echo "\$$var_name")
+            line=${line//\$\{$var_name\}/$var_value}
         done
         echo "$line"
-    done < "$temp_file" > "$config_output"
-    rm "$temp_file"
+    done < "$config_template" > "$config_output"
 
     echo "Config file generated at $config_output"
 }
 
-# Example usage in your startup script
+# Run the function to replace variables and start headscale
 replace_config_values
-headscale
\ No newline at end of file
+headscale