CloudWatch Logs examples using AWS SDK for .NET - AWS SDK for .NET
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CloudWatch Logs examples using AWS SDK for .NET

The following code examples show you how to perform actions and implement common scenarios by using the AWS SDK for .NET with CloudWatch Logs.

Actions are code excerpts from larger programs and must be run in context. While actions show you how to call individual service functions, you can see actions in context in their related scenarios.

Each example includes a link to the complete source code, where you can find instructions on how to set up and run the code in context.

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Actions

The following code example shows how to use AssociateKmsKey.

AWS SDK for .NET
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

    using System;
    using System.Threading.Tasks;
    using Amazon.CloudWatchLogs;
    using Amazon.CloudWatchLogs.Model;

    /// <summary>
    /// Shows how to associate an AWS Key Management Service (AWS KMS) key with
    /// an Amazon CloudWatch Logs log group.
    /// </summary>
    public class AssociateKmsKey
    {
        public static async Task Main()
        {
            // This client object will be associated with the same AWS Region
            // as the default user on this system. If you need to use a
            // different AWS Region, pass it as a parameter to the client
            // constructor.
            var client = new AmazonCloudWatchLogsClient();

            string kmsKeyId = "arn:aws:kms:us-west-2:<account-number>:key/7c9eccc2-38cb-4c4f-9db3-766ee8dd3ad4";
            string groupName = "cloudwatchlogs-example-loggroup";

            var request = new AssociateKmsKeyRequest
            {
                KmsKeyId = kmsKeyId,
                LogGroupName = groupName,
            };

            var response = await client.AssociateKmsKeyAsync(request);

            if (response.HttpStatusCode == System.Net.HttpStatusCode.OK)
            {
                Console.WriteLine($"Successfully associated KMS key ID: {kmsKeyId} with log group: {groupName}.");
            }
            else
            {
                Console.WriteLine("Could not make the association between: {kmsKeyId} and {groupName}.");
            }
        }
    }

The following code example shows how to use CancelExportTask.

AWS SDK for .NET
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

    using System;
    using System.Threading.Tasks;
    using Amazon.CloudWatchLogs;
    using Amazon.CloudWatchLogs.Model;

    /// <summary>
    /// Shows how to cancel an Amazon CloudWatch Logs export task.
    /// </summary>
    public class CancelExportTask
    {
        public static async Task Main()
        {
            // This client object will be associated with the same AWS Region
            // as the default user on this system. If you need to use a
            // different AWS Region, pass it as a parameter to the client
            // constructor.
            var client = new AmazonCloudWatchLogsClient();
            string taskId = "exampleTaskId";

            var request = new CancelExportTaskRequest
            {
                TaskId = taskId,
            };

            var response = await client.CancelExportTaskAsync(request);

            if (response.HttpStatusCode == System.Net.HttpStatusCode.OK)
            {
                Console.WriteLine($"{taskId} successfully canceled.");
            }
            else
            {
                Console.WriteLine($"{taskId} could not be canceled.");
            }
        }
    }

The following code example shows how to use CreateExportTask.

AWS SDK for .NET
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

    using System;
    using System.Threading.Tasks;
    using Amazon.CloudWatchLogs;
    using Amazon.CloudWatchLogs.Model;

    /// <summary>
    /// Shows how to create an Export Task to export the contents of the Amazon
    /// CloudWatch Logs to the specified Amazon Simple Storage Service (Amazon S3)
    /// bucket.
    /// </summary>
    public class CreateExportTask
    {
        public static async Task Main()
        {
            // This client object will be associated with the same AWS Region
            // as the default user on this system. If you need to use a
            // different AWS Region, pass it as a parameter to the client
            // constructor.
            var client = new AmazonCloudWatchLogsClient();
            string taskName = "export-task-example";
            string logGroupName = "cloudwatchlogs-example-loggroup";
            string destination = "amzn-s3-demo-bucket";
            var fromTime = 1437584472382;
            var toTime = 1437584472833;

            var request = new CreateExportTaskRequest
            {
                From = fromTime,
                To = toTime,
                TaskName = taskName,
                LogGroupName = logGroupName,
                Destination = destination,
            };

            var response = await client.CreateExportTaskAsync(request);

            if (response.HttpStatusCode == System.Net.HttpStatusCode.OK)
            {
                Console.WriteLine($"The task, {taskName} with ID: " +
                                  $"{response.TaskId} has been created successfully.");
            }
        }
    }

The following code example shows how to use CreateLogGroup.

AWS SDK for .NET
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

    using System;
    using System.Threading.Tasks;
    using Amazon.CloudWatchLogs;
    using Amazon.CloudWatchLogs.Model;

    /// <summary>
    /// Shows how to create an Amazon CloudWatch Logs log group.
    /// </summary>
    public class CreateLogGroup
    {
        public static async Task Main()
        {
            // This client object will be associated with the same AWS Region
            // as the default user on this system. If you need to use a
            // different AWS Region, pass it as a parameter to the client
            // constructor.
            var client = new AmazonCloudWatchLogsClient();

            string logGroupName = "cloudwatchlogs-example-loggroup";

            var request = new CreateLogGroupRequest
            {
                LogGroupName = logGroupName,
            };

            var response = await client.CreateLogGroupAsync(request);

            if (response.HttpStatusCode == System.Net.HttpStatusCode.OK)
            {
                Console.WriteLine($"Successfully create log group with ID: {logGroupName}.");
            }
            else
            {
                Console.WriteLine("Could not create log group.");
            }
        }
    }

  • For API details, see CreateLogGroup in AWS SDK for .NET API Reference.

The following code example shows how to use CreateLogStream.

AWS SDK for .NET
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

    using System;
    using System.Threading.Tasks;
    using Amazon.CloudWatchLogs;
    using Amazon.CloudWatchLogs.Model;

    /// <summary>
    /// Shows how to create an Amazon CloudWatch Logs stream for a CloudWatch
    /// log group.
    /// </summary>
    public class CreateLogStream
    {
        public static async Task Main()
        {
            // This client object will be associated with the same AWS Region
            // as the default user on this system. If you need to use a
            // different AWS Region, pass it as a parameter to the client
            // constructor.
            var client = new AmazonCloudWatchLogsClient();
            string logGroupName = "cloudwatchlogs-example-loggroup";
            string logStreamName = "cloudwatchlogs-example-logstream";

            var request = new CreateLogStreamRequest
            {
                LogGroupName = logGroupName,
                LogStreamName = logStreamName,
            };

            var response = await client.CreateLogStreamAsync(request);

            if (response.HttpStatusCode == System.Net.HttpStatusCode.OK)
            {
                Console.WriteLine($"{logStreamName} successfully created for {logGroupName}.");
            }
            else
            {
                Console.WriteLine("Could not create stream.");
            }
        }
    }

The following code example shows how to use DeleteLogGroup.

AWS SDK for .NET
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

    using System;
    using System.Threading.Tasks;
    using Amazon.CloudWatchLogs;
    using Amazon.CloudWatchLogs.Model;

    /// <summary>
    /// Uses the Amazon CloudWatch Logs Service to delete an existing
    /// CloudWatch Logs log group.
    /// </summary>
    public class DeleteLogGroup
    {
        public static async Task Main()
        {
            var client = new AmazonCloudWatchLogsClient();
            string logGroupName = "cloudwatchlogs-example-loggroup";

            var request = new DeleteLogGroupRequest
            {
                LogGroupName = logGroupName,
            };

            var response = await client.DeleteLogGroupAsync(request);

            if (response.HttpStatusCode == System.Net.HttpStatusCode.OK)
            {
                Console.WriteLine($"Successfully deleted CloudWatch log group, {logGroupName}.");
            }
        }
    }

  • For API details, see DeleteLogGroup in AWS SDK for .NET API Reference.

The following code example shows how to use DescribeExportTasks.

AWS SDK for .NET
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

    using System;
    using System.Threading.Tasks;
    using Amazon.CloudWatchLogs;
    using Amazon.CloudWatchLogs.Model;

    /// <summary>
    /// Shows how to retrieve a list of information about Amazon CloudWatch
    /// Logs export tasks.
    /// </summary>
    public class DescribeExportTasks
    {
        public static async Task Main()
        {
            // This client object will be associated with the same AWS Region
            // as the default user on this system. If you need to use a
            // different AWS Region, pass it as a parameter to the client
            // constructor.
            var client = new AmazonCloudWatchLogsClient();

            var request = new DescribeExportTasksRequest
            {
                Limit = 5,
            };

            var response = new DescribeExportTasksResponse();

            do
            {
                response = await client.DescribeExportTasksAsync(request);
                response.ExportTasks.ForEach(t =>
                {
                    Console.WriteLine($"{t.TaskName} with ID: {t.TaskId} has status: {t.Status}");
                });
            }
            while (response.NextToken is not null);
        }
    }

The following code example shows how to use DescribeLogGroups.

AWS SDK for .NET
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

    using System;
    using System.Threading.Tasks;
    using Amazon.CloudWatchLogs;
    using Amazon.CloudWatchLogs.Model;

    /// <summary>
    /// Retrieves information about existing Amazon CloudWatch Logs log groups
    /// and displays the information on the console.
    /// </summary>
    public class DescribeLogGroups
    {
        public static async Task Main()
        {
            // Creates a CloudWatch Logs client using the default
            // user. If you need to work with resources in another
            // AWS Region than the one defined for the default user,
            // pass the AWS Region as a parameter to the client constructor.
            var client = new AmazonCloudWatchLogsClient();

            bool done = false;
            string newToken = null;

            var request = new DescribeLogGroupsRequest
            {
                Limit = 5,
            };

            DescribeLogGroupsResponse response;

            do
            {
                if (newToken is not null)
                {
                    request.NextToken = newToken;
                }

                response = await client.DescribeLogGroupsAsync(request);

                response.LogGroups.ForEach(lg =>
                {
                    Console.WriteLine($"{lg.LogGroupName} is associated with the key: {lg.KmsKeyId}.");
                    Console.WriteLine($"Created on: {lg.CreationTime.Date.Date}");
                    Console.WriteLine($"Date for this group will be stored for: {lg.RetentionInDays} days.\n");
                });

                if (response.NextToken is null)
                {
                    done = true;
                }
                else
                {
                    newToken = response.NextToken;
                }
            }
            while (!done);
        }
    }

The following code example shows how to use StartLiveTail.

AWS SDK for .NET

Include the required files.

using Amazon;
using Amazon.CloudWatchLogs;
using Amazon.CloudWatchLogs.Model;

Start the Live Tail session.

            var client = new AmazonCloudWatchLogsClient();
            var request = new StartLiveTailRequest
            {
                LogGroupIdentifiers = logGroupIdentifiers,
                LogStreamNames = logStreamNames,
                LogEventFilterPattern = filterPattern,
            };

            var response = await client.StartLiveTailAsync(request);

            // Catch if request fails
            if (response.HttpStatusCode != System.Net.HttpStatusCode.OK)
            {
                Console.WriteLine("Failed to start live tail session");
                return;
            }

You can handle the events from the Live Tail session in two ways:

            /* Method 1
            * 1). Asynchronously loop through the event stream
            * 2). Set a timer to dispose the stream and stop the Live Tail session at the end.
            */
            var eventStream = response.ResponseStream;
            var task = Task.Run(() => 
            {
                foreach (var item in eventStream)
                {
                    if (item is LiveTailSessionUpdate liveTailSessionUpdate)
                    {
                        foreach (var sessionResult in liveTailSessionUpdate.SessionResults)
                        {
                            Console.WriteLine("Message : {0}", sessionResult.Message);
                        }
                    }
                    if (item is LiveTailSessionStart)
                    {
                        Console.WriteLine("Live Tail session started");
                    }
                    // On-stream exceptions are processed here
                    if (item is CloudWatchLogsEventStreamException)
                    {
                        Console.WriteLine($"ERROR: {item}");
                    }
                }
            });
            // Close the stream to stop the session after a timeout
            if (!task.Wait(TimeSpan.FromSeconds(10))){
                eventStream.Dispose();
                Console.WriteLine("End of line");
            }


            /* Method 2
            * 1). Add event handlers to each event variable
            * 2). Start processing the stream and wait for a timeout using AutoResetEvent
            */
            AutoResetEvent endEvent = new AutoResetEvent(false);
            var eventStream = response.ResponseStream;
            using (eventStream) // automatically disposes the stream to stop the session after execution finishes
            {
                eventStream.SessionStartReceived += (sender, e) =>
                {
                    Console.WriteLine("LiveTail session started");
                };
                eventStream.SessionUpdateReceived += (sender, e) =>
                {   
                    foreach (LiveTailSessionLogEvent logEvent in e.EventStreamEvent.SessionResults){
                        Console.WriteLine("Message: {0}", logEvent.Message);
                    }
                };
                // On-stream exceptions are captured here
                eventStream.ExceptionReceived += (sender, e) => 
                {
                    Console.WriteLine($"ERROR: {e.EventStreamException.Message}");
                };

                eventStream.StartProcessing();
                // Stream events for this amount of time.
                endEvent.WaitOne(TimeSpan.FromSeconds(10));
                Console.WriteLine("End of line");
            }

  • For API details, see StartLiveTail in AWS SDK for .NET API Reference.