Upload Trace Log Files Directly to Azure

Question

I'm using System Diagnostics trace writing to do logging in my application. I want to upload my log files to Azure Storage. I'm able to do so but only by uploading logs that are stored in my project folder. I created a custom Trace Listener to direct where the file is uploaded.

public TextLogTraceListener(string filePath, string db)
    {
        filePath = filePath + db + "\\" + DateTime.Now.ToString("MMddyyyy") + "_mylog.log";
        logFileLocation = filePath;
        traceWriter = new StreamWriter(filePath, true);
        traceWriter.AutoFlush = true;
    }

In a separate function I'm using the following code to upload the log file stored in my project folder to the Azure storage

using (var fileStream = File.OpenRead(path))
{
     blockBlob.UploadFromStream(fileStream);
}

However, I want to cut out the middle-man and upload the logs directly to the Azure storage. How do I go about that?

Answer 1

If you want to use Azure blob storage as your log file system, we can use Azure append blob to store log file.

For example

1. Create a custom Trace Listener

public class BlobWriterStorageListener : TraceListener
    {
// Install package Microsoft.Azure.Storage.Blob
        protected override string[] GetSupportedAttributes()
        {
            return new[] { "StorageConnectionString", "LogsContainerName", "LogFileName" };
        }

        public override void Write(string message, string category) {
            string stroageConnectionString = Attributes["StorageConnectionString"];
            string logsContainerName = Attributes["LogsContainerName"];
            string logFileName = Attributes["LogFileName"];
            CloudStorageAccount storageAccount = CloudStorageAccount.Parse(stroageConnectionString);

            CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

            CloudBlobContainer container = blobClient.GetContainerReference(logsContainerName);
            container.CreateIfNotExists();

            CloudAppendBlob appendBlob = container.GetAppendBlobReference(logFileName);

            // when the blob does not exist, create it.
            if (!appendBlob.Exists()) {
                appendBlob.CreateOrReplace();
            }
            appendBlob.AppendText(String.Format("[Timestamp: {2:u}] Message:{0} Category:{1}", message, category, DateTime.UtcNow));

        }

        public override void WriteLine(string message, string category)
        {
            Write(message, category +"\n");
        }

        public override void Write(string message)
        {
            Write(message, null);
        }

        public override void WriteLine(string message)
        {
            Write(message + "\n");
        }

2. Test

 static void Main(string[] args)
        {
            TraceListener ooblistener = new BlobWriterStorageListener();

            ooblistener.Name = "AzureBlobStorageListener";
            ooblistener.Attributes.Add("type", "BlobTrace.BlobWriterStorageListener");
            ooblistener.Attributes.Add("StorageConnectionString", "<your storage connection string>");
            ooblistener.Attributes.Add("LogsContainerName", "logs");
            ooblistener.Attributes.Add("LogFileName", "application.log");

            Trace.Listeners.Add(ooblistener);

            Trace.WriteLine("Hey There!!", EventLogEntryType.Information.ToString());
            Thread.Sleep(60000);

            Trace.WriteLine("Hey Here!!", EventLogEntryType.Information.ToString());
            Console.ReadLine();
        }