Logging Output of Azure Startup Tasks to the Event Log

This can come in handy when troubleshooting:

using System;

using System.Diagnostics;

using System.Text;

 

namespace Thinktecture.Azure

{

    class Program

    {

        static EventLog _eventLog = new EventLog(“Application”, “.”, “StartupTaskShell”);

        static StringBuilder _out = new StringBuilder(64);

        static StringBuilder _err = new StringBuilder(64);

 

        static int Main(string[] args)

        {

            if (args.Length != 1)

            {

                Console.WriteLine(“Invalid arguments: “ + String.Join(“, “, args));

                _eventLog.WriteEntry(“Invalid arguments: “ + String.Join(“, “, args));

               

                return -1;

            }

 

            var task = args[0];

 

            ProcessStartInfo info = new ProcessStartInfo()

            {

                FileName = task,

                WorkingDirectory = Environment.CurrentDirectory,

                UseShellExecute = false,

                ErrorDialog = false,

                CreateNoWindow = true,

                RedirectStandardOutput = true,

                RedirectStandardError = true

            };

 

            var process = new Process();

            process.StartInfo = info;

 

            process.OutputDataReceived += (s, e) =>

                {

                    if (e.Data != null)

                    {

                        _out.AppendLine(e.Data);

                    }

                };

            process.ErrorDataReceived += (s, e) =>

                {

                    if (e.Data != null)

                    {

                        _err.AppendLine(e.Data);

                    }

                };

 

            process.Start();

            process.BeginOutputReadLine();

            process.BeginErrorReadLine();

            process.WaitForExit();

 

            var outString = _out.ToString();

            var errString = _err.ToString();

 

            if (!string.IsNullOrWhiteSpace(outString))

            {

                outString = String.Format(“Standard Out for {0}nn{1}”, task, outString);

                _eventLog.WriteEntry(outString, EventLogEntryType.Information);

            }

 

            if (!string.IsNullOrWhiteSpace(errString))

            {

                errString = String.Format(“Standard Err for {0}nn{1}”, task, errString);

                _eventLog.WriteEntry(errString, EventLogEntryType.Error);

            }

 

            return 0;

        }

    }

}

You then wrap your startup tasks with the StartupTaskShell and you’ll be able to see stdout and stderr in the application event log.

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