All log files need to be written per day in a rolling mode.
However, I have a question how can I implement the rolling log file for the current file without date,
we need the following logic:
.log => current log file
.log.date => old log files,
This the code what I implement however after executing I found the current file with the date.
var log = new LoggerConfiguration()
.MinimumLevel.Debug()
.WriteTo.RollingFile(#"C:\project\SerilogFile.txt", retainedFileCountLimit: 7)
.CreateLogger();
Related
I am writing an uwp app with C# and I would like to use serilog to write logfiles.
When I do it in a .NET Core Console application it creates the file with the wanted content.
In the uwp I can show the log messages on the GUI, but no log file is created (yes, I have broadFileSystemAccess).
My code:
Log.Logger = new LoggerConfiguration().WriteTo.File("log.txt").CreateLogger();
Log.Debug("TEST");
Log.CloseAndFlush();
I would expect that it creates log.txt file in the directory which can be get with Windows.Storage.ApplicationData.Current.LocalFolder like
storageFolder.CreateFileAsync("test.txt", CreationCollisionOption.ReplaceExisting);
does.
Can anyone tell me what I have to change or to consider to log to a file with serilog in my uwp app?
One of the great things about Serilog is that it's open-source and you can look at its source code and see what it is doing / how it works.
If you peek at the source code of the File sink, you'll notice that it is simply opening a file via System.IO.File.Open on the same folder where your app is running, which running from Visual Studio is probably going to be something like C:\Users\augustoproiete\MyApp\MyUwpApp\bin\x64\Debug\AppX\ where you don't have access to write file.
That means you have to be explicit about where to store the file, for example in the application data folder of your app. E.g.:
var logFilePath = Path.Combine(ApplicationData.Current.LocalFolder.Path, "log.txt");
Log.Logger = new LoggerConfiguration().WriteTo.File(logFilePath).CreateLogger();
Log.Debug("TEST");
Log.CloseAndFlush();
I'd recommend you read the Debugging and Diagnostics page on Serilog's docs, as it explains how you see error messages from Serilog - which you'd have seen that it was failing to create a file and the path it was using.
Thank yu for your answer!
I thought that the local folder path is automatically used, so I did not try that.
I jus had to modify the code as follows
var logFilePath = Path.Combine(ApplicationData.Current.LocalFolder.Path, "log.txt");
Log.Logger = new LoggerConfiguration()
.MinimumLevel.Verbose() //otherwise Debug is not logged
.WriteTo.File(logFilePath)
.CreateLogger();
Log.Debug("TEST");
Log.CloseAndFlush();
then it woked and wrote the Debug message to the log file :)
Thank you very much!
I am using Serilog library in a C# Console Application to build a Scheduler, which logs messages in a Log File for each day. The filenames are created dynamically using below code.
Log.Logger = new LoggerConfiguration()
.WriteTo.Console()
.WriteTo.File("logs\\log-scheduler-.txt", rollingInterval: RollingInterval.Day)
.CreateLogger();
How can I get to know the Name of File that my Console application has created? At the end of my program, I want to email the log file as attachment.
Serilog doesn't expose a way to inspect the name of the file(s) that were created, as of this writing.
If you don't use a RollingInterval and have the log messages be written to a single file, then you know exactly what the name of the file is, because you already specified it in the log pipeline configuration: logs\\log-scheduler-.txt.
But if you want to use a RollingInterval then you what you could do, is to inspect the folder where your log files are being written to, and find the log file(s) that were updated since your application started, by capturing the current timestamp when your app starts, and then looking at the LastWriteTimeUtc attribute of the log files in the file system to see anything that has changed since that time.
e.g.
DateTime appStartTime = DateTime.UtcNow;
// ... (app code)
// Ensure that all messages are flushed to the file
Log.CloseAndFlush();
// Get all log files modified since the app started
var logFilesUpdatedInThisSession = new DirectoryInfo(#"C:\Temp\logs\")
.EnumerateFileSystemInfos("log-scheduler-*.txt")
.Where(f => f.LastWriteTimeUtc >= appStartTime)
.OrderBy(f => f.LastWriteTimeUtc)
.ToList();
if (logFilesUpdatedInThisSession.Any())
{
// Send all files via e-mail ...
}
Another alternative (better IMO) would be to not send e-mails at all from your app, and just ship the logs to a server, such as a Seq server which allows you to easily browse the logs, apply filters, etc., which is a much better experience than opening a log file attached to an e-mail on a text editor.
I have an ASP.NET Core 2.0 Application. I'm creating a Dev only page that allows me to download the Serilog log file(s).
The log files are on a day rolling interval. I cannot download the current day's file. An IOException is thrown stating the file is being used by another process.
It seems only the log file for the current day is blocked.
Is there a way to release whatever has control on the file, download it, and then re-attach it?
public FileContentResult DownloadLog(string name){
string path = Directory.GetCurrentDirectory() + $"\\Logs\{name}"
byte[] = System.IO.File.ReadAllBytes(path); //Exception thrown here
return File(...);
}
When you configure Serilog with WriteTo.File(), you need to pass shared: true to allow other processes to read it concurrently. I.e.:
.WriteTo.File("logs.txt", shared: true)
I want to be able to send application logs to Cloud Watch Log. and I got to know that there is a Cloud Watch Agent service that runs in the background and reads logs from log file and send only the delta (extra logs) to Cloud Watch Log. All this makes sense to me. Then I got to know about NLog a C# logging framework, and wrote below POC to send logs.
static void Main(string[] args)
{
ConfigureNLog();
var logger = NLog.LogManager.GetCurrentClassLogger();
logger.Info("Hello World");
logger.Log(LogLevel.Info, "Sample informational message");
}
static void ConfigureNLog()
{
var accessKey = ConfigurationManager.AppSettings.Get("AWSAccessKey");
var secretKey = ConfigurationManager.AppSettings.Get("AWSSecretKey");
var config = new LoggingConfiguration();
var awsTarget = new AWSTarget()
{
LogGroup = "NLog.ProgrammaticConfigurationExample",
Region = "us-east-1",
Credentials = new BasicAWSCredentials(accessKey, secretKey)
};
config.AddTarget("aws", awsTarget);
config.LoggingRules.Add(new LoggingRule("*", LogLevel.Debug, awsTarget));
LogManager.Configuration = config;
}
Now when I run above code, I am able to send log to Cloud Watch. But I am confused now, where is the significance of Cloud Watch Agent?
Since I am directly sending log data, does that mean I don't need Cloud Watch Agent in my scenario?
In case I want to use Cloud Watch Agent then I need to use FILE as a target for logs by NLog and then tell Cloud Watch Agent to send that log file to Cloud Watch Log??
Is my understanding correct? Please help me in understanding the flow.
Is below flow correct?
NLog write log to File -> Cloud Agent read log from there -> Send log
to Cloud Watch
Question: How to use Cloud Watch Agent in above POC to send data via NLog?
Cloud Watch Agent runs on your server and can watch logs files that are produced. These log files can be anything, IIS Logs, Time Logs, Event Log, Etc. When the log file is updated, CWA will grab the updates and send to Cloud Watch. This is the generic behavior of the CWA and is great for Event Logs and OS logging.
By modifying the AWS.EC2.Windows.CloudWatch.json CWA json file, you can configure it to watch log files for certain formats and send changes to CW outside the standard/example ones it does by default. You can update the json to your NLog entry layout format and have it watch for that specific format in the file. CW Does have a delay sending.
Now you have Nlog which writes log files. You can have NLog send the log entries to a file and have the Cloud Watch Agent watch that file, pick up the change and send it or you can have NLog send the entries directly to CW. Since you are writing directly to CW through a NLog target, you don't need the Cloud Agent for your NLog files. I suggest keeping CWA for other log files like IIS or event logs.
I guess it is a matter a preference on how you do it. I think NLog Targets with layouts is easier than dealing with the CloudWatch json file to try and match the log format. I only use CWA to send log files I have no control over and use a NLog Target to send my NLog entries.
I can post an example CWA json snippet for a 3rd party log file I monitor with CWA if you need an example.
When an application just have to write to a file, then it lives a very simple life with few problems.
When an application suddenly have to handle network traffic (with timeouts, disconnects, retries, connectivity, latency, etc.) then it suddenly will have issues with things queuing up, taking memory, using sockets, causing garbage collections, stalls, etc. (And loosing all pending logevents on crash)
Depending on the lifetime of your application and the critically of your applications, then it can be useful to give it a simple life. And let a friend like Cloud Watch Agent worry about the network-stuff.
See also https://github.com/NLog/NLog.Extensions.Logging/wiki/NLog-cloud-logging-with-Azure-function-or-AWS-lambda
I know it's possible to log in both file and database and also in more than one resource,but is there any way to configure log4net if it failed to log in the database it log to the file automatically?