I have a GCS bucket where I upload .tar.gz files. A notification to the app in Kubernetes Engine is sent by Google PUB-SUB whenever there is a new file upload. App has listener that listens to the notification and has to read the .tar.gz file.

I have set up topic/subscribesr notification from GCS to the APP. I am unable to determine how to read .tar.gz file when notification comes.

I tried below code to read .tar.gz but its not what I should be doing. It gave non readable characters & i am not unzipping it. I used google-cloud-storage lib.

if(map.containsValue("OBJECT_FINALIZE") ){
           Storage storage = StorageOptions.newBuilder()
                    .setProjectId(projectId)
                    .setCredentials(creaCredentialsProvider.getCredentials()).build().getService();


           try(ReadChannel reader = storage.reader(archiveMessage.getBucket(), archiveMessage.getName())){
               ByteBuffer bytes = ByteBuffer.allocate(64 * 1024);
               while (reader.read(bytes) > 0) {
                   bytes.flip();
                   System.out.println((char)bytes.get());
                   bytes.clear();
               }

           }


        }

I looked at persistent disks & transcoding which doesn't look straight forward. Any help with direction I should be going or code samples are really appreciated.