String-based headers/content sanitizer implementation

It would be convenient if we provide a simple headers/content sanitizer which filters the stringified headers/content. For example, a user had to implement a sanitizer like the following:

   @Nonnull
   public static String changeLogWithoutSensitiveData(@Nonnull Object request) {
       String requestMessage = request.toString();

       if(!isRequireFiltering(requestMessage)) {
           return requestMessage;
       }

       return filterSensitiveData(requestMessage);
   }

   private static boolean isRequireFiltering(@Nonnull String message) {
       if(removeContentNames.stream().noneMatch(message::contains)) {
           return false;
       }

       return true;
   }

   @Nonnull
   private static String filterSensitiveData(@Nonnull String message) {
       Matcher matcher;

       for(Pattern pattern : removeContentRegxs) {
           matcher = pattern.matcher(message);
           message = matcher.replaceAll("");
       }

       return message;
   }

We could make the following changes:

• Change the return type of header sanitizers from HttpHeaders to ? so that a user can return any object such as String.

• Provide an abstract sanitizer implementation that converts headers or content to a String and filters it as instructed by its abstract methods such as boolean needsSanitization() and String sanitize(String).

  • Provide a concrete implementation that implements needsSanitization() and sanitize() to filter the String using regular expression(s).

• Add some convenience methods to LoggingClient/ServiceBuilder and RequestLog.toString*():

  new LoggingClientBuilder()
          .requestContentSanitizer(Pattern.compile(...),
                                   Pattern.compile(...))
          ....
  

[amitvc]

@trustin I can implement this. I am new to the project but I am interested in contributing. Can I take this please?

[amitvc]

@trustin There is a PR for this issue https://github.com/line/armeria/pull/2721