#r "Newtonsoft.Json"
using System;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
using Newtonsoft.Json;
// The input json
public class InputObject {
public String stringValue1 {get; set;}
public String stringValue2 {get; set;}
public String stringValue3 {get; set;}
public String stringValue4 {get; set;}
}
// Class for what should be sent to Log Analytics
public class InputJson
{
public string StringField1 { get; set; }
public string StringField2 { get; set; }
public string StringField3 { get; set; }
public string StringField4 { get; set; }
}
public static void Run(InputObject req, TraceWriter log)
{
log.Info("Start function to add information to Log Analytics");
// Update customerId to your Operations Management Suite workspace ID
string customerId = "LogAnalyticsWorkspaceId";
// For sharedKey, use either the primary or the secondary Connected Sources client authentication key
string sharedKey = "LogAnalyticsWorkspaceKey
// LogName is name of the event type that is being submitted to Log Analytics
string LogName = "AzureFunctionLog";
// Creates the JSON object, with key/value pairs
InputJson jsonObj = new InputJson();
jsonObj.StringField1 = req?.stringValue1;
jsonObj.StringField2 = req?.stringValue2;
jsonObj.StringField3 = req?.stringValue3;
jsonObj.StringField4 = req?.stringValue4;
// Convert object to json
var json = JsonConvert.SerializeObject(jsonObj);
log.Info("json file sent to Log Analytics: " + json);
// Create a hash for the API signature
var datestring = DateTime.UtcNow.ToString("r");
string stringToHash = "POST\n" + json.Length + "\napplication/json\n" + "x-ms-date:" + datestring + "\n/api/logs";
string hashedString = BuildSignature(stringToHash, sharedKey);
string signature = "SharedKey " + customerId + ":" + hashedString;
PostData(signature, datestring, json, customerId, LogName);
}
// Build the API signature
public static 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 static void PostData(string signature, string date, string json, string customerId, string LogName)
{
// You can use an optional field to specify the timestamp from the data. If the time field is not specified, Log Analytics assumes the time is the message ingestion time
string TimeStampField = "";
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", TimeStampField);
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);
}
}
