LAWorkspace.cs

using System.Text;
using System.Net.Http.Headers;
using System.Security.Cryptography;

namespace AzureMySQLMetricsCollector
{
    class LAWorkspace
    {
        //ref: https://docs.microsoft.com/en-us/azure/azure-monitor/logs/data-collector-api

        // You can use an optional field to specify the timestamp from the data. 
        // If the time field is not specified, Azure Monitor assumes the time is the message ingestion time
        //public string TimeStampField { get; set; }

        // Update customerId to your Log Analytics workspace ID
        public string CustomerId { get; set; }

        // For sharedKey, use either the primary or the secondary Connected Sources client authentication key   
        public string SharedKey { get; set; }

        // LogName is name of the event type that is being submitted to Azure Monitor
        //public string LogName { get; set; }
        public string LogName = "AzMySQLMetricsCollector";

        // An example JSON object, with key/value pairs
        //private readonly string  strJson = @"[{""DemoField1"":""DemoValue1"",""DemoField2"":""DemoValue2""},{""DemoField3"":""DemoValue3"",""DemoField4"":""DemoValue4""}]";

        public LAWorkspace()
        {
        }

        public void InjestLog(string strJsonPayload, string strLogName)
        {
            // Create a hash for the API signature
            var datestring = DateTime.UtcNow.ToString("r");
            var jsonBytes = Encoding.UTF8.GetBytes(strJsonPayload);
            string stringToHash = "POST\n" + jsonBytes.Length + "\napplication/json\n" + "x-ms-date:" + datestring + "\n/api/logs";
            string hashedString = BuildSignature(stringToHash, SharedKey);
            string signature = "SharedKey " + CustomerId + ":" + hashedString;

            PostData(signature, datestring, strJsonPayload, strLogName);
        }
        // Build the API signature
        public string BuildSignature(string message, string secret)
        {
            var encoding = new System.Text.ASCIIEncoding();
            byte[] keyByte = Convert.FromBase64String(secret);
            byte[] messageBytes = encoding.GetBytes(message);
            using (var hmacsha256 = new HMACSHA256(keyByte))
            {
                byte[] hash = hmacsha256.ComputeHash(messageBytes);
                return Convert.ToBase64String(hash);
            }
        }

        // Send a request to the POST API endpoint
        public void PostData(string signature, string date, string json, string logName)
        {
            try
            {
                string url = "https://" + CustomerId + ".ods.opinsights.azure.com/api/logs?api-version=2016-04-01";

                System.Net.Http.HttpClient client = new System.Net.Http.HttpClient();
                client.DefaultRequestHeaders.Add("Accept", "application/json");
                client.DefaultRequestHeaders.Add("Log-Type", logName);
                client.DefaultRequestHeaders.Add("Authorization", signature);
                client.DefaultRequestHeaders.Add("x-ms-date", date);
                client.DefaultRequestHeaders.Add("time-generated-field", date);

                System.Net.Http.HttpContent httpContent = new StringContent(json, Encoding.UTF8);
                httpContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");
                Task<System.Net.Http.HttpResponseMessage> response = client.PostAsync(new Uri(url), httpContent);

                System.Net.Http.HttpContent responseContent = response.Result.Content;
                string result = responseContent.ReadAsStringAsync().Result;
                Console.WriteLine("Return Result: " + result);
            }
            catch (Exception excep)
            {
                Console.WriteLine("API Post Exception: " + excep.Message);
            }
        }
    }
}