CloudWatch Logs examples using AWS CLI

The following code examples show you how to perform actions and implement common scenarios by using the AWS Command Line Interface 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.

Actions

create-log-group

The following code example shows how to use create-log-group.

AWS CLI

To create a log group

The following create-log-group example creates a log group named my-logs.

aws logs create-log-group \
    --log-group-name my-logs

This command produces no output.

For more information, see Working with log groups and log streams in the Amazon CloudWatch Logs User Guide.

• For API details, see CreateLogGroup in AWS CLI Command Reference.

create-log-stream

The following code example shows how to use create-log-stream.

AWS CLI

To create a log stream

The following create-log-stream example creates a log stream named 20150601 in the log group my-logs.

aws logs create-log-stream \
    --log-group-name my-logs \
    --log-stream-name 20150601

This command produces no output.

For more information, see Working with log groups and log streams in the Amazon CloudWatch Logs User Guide.

• For API details, see CreateLogStream in AWS CLI Command Reference.

delete-log-group

The following code example shows how to use delete-log-group.

AWS CLI

To delete a log group

The following delete-log-group example deletes a log group named my-logs.

aws logs delete-log-group \
    --log-group-name my-logs

This command produces no output.

For more information, see Working with log groups and log streams in the Amazon CloudWatch Logs User Guide.

• For API details, see DeleteLogGroup in AWS CLI Command Reference.

delete-log-stream

The following code example shows how to use delete-log-stream.

AWS CLI

To delete a log stream

The following delete-log-stream example deletes a log stream named 20150531 from a log group named my-logs.

aws logs delete-log-stream \
    --log-group-name my-logs \
    --log-stream-name 20150531

This command produces no output.

For more information, see Working with log groups and log streams in the Amazon CloudWatch Logs User Guide.

• For API details, see DeleteLogStream in AWS CLI Command Reference.

delete-retention-policy

The following code example shows how to use delete-retention-policy.

AWS CLI

To delete the retention policy of a log group

The following delete-retention-policy example removes the retention policy that has previously been applied to a log group named my-logs.

aws logs delete-retention-policy \
    --log-group-name my-logs

This command produces no output.

For more information, see Working with log groups and log streams in the Amazon CloudWatch Logs User Guide.

• For API details, see DeleteRetentionPolicy in AWS CLI Command Reference.

describe-log-groups

The following code example shows how to use describe-log-groups.

AWS CLI

To describe a log group

The following describe-log-groups example describes a log group named my-logs.

aws logs describe-log-groups \
    --log-group-name-prefix my-logs

Output:

{
    "logGroups": [
        {
            "storedBytes": 0,
            "metricFilterCount": 0,
            "creationTime": 1433189500783,
            "logGroupName": "my-logs",
            "retentionInDays": 5,
            "arn": "arn:aws:logs:us-west-2:0123456789012:log-group:my-logs:*"
        }
    ]
}

For more information, see Working with log groups and log streams in the Amazon CloudWatch Logs User Guide.

• For API details, see DescribeLogGroups in AWS CLI Command Reference.

describe-log-streams

The following code example shows how to use describe-log-streams.

AWS CLI

To describe the log streams in a log group

The following describe-log-streams example shows all log streams starting with the prefix 2015 in the log group my-logs.

aws logs describe-log-streams \
    --log-group-name my-logs \
    --log-stream-name-prefix 2015

Output:

{
    "logStreams": [
        {
            "creationTime": 1433189871774,
            "arn": "arn:aws:logs:us-west-2:0123456789012:log-group:my-logs:log-stream:20150531",
            "logStreamName": "20150531",
            "storedBytes": 0
        },
        {
            "creationTime": 1433189873898,
            "arn": "arn:aws:logs:us-west-2:0123456789012:log-group:my-logs:log-stream:20150601",
            "logStreamName": "20150601",
            "storedBytes": 0
        }
    ]
}

For more information, see Working with log groups and log streams in the Amazon CloudWatch Logs User Guide.

• For API details, see DescribeLogStreams in AWS CLI Command Reference.

get-log-events

The following code example shows how to use get-log-events.

AWS CLI

To get log events from a log stream

The following get-log-events example retrieves log events from a log stream named 20150601 in the log group my-logs.

aws logs get-log-events \
    --log-group-name my-logs \
    --log-stream-name 20150601

Output:

{
    "nextForwardToken": "f/31961209122447488583055879464742346735121166569214640130",
    "events": [
        {
            "ingestionTime": 1433190494190,
            "timestamp": 1433190184356,
            "message": "Example Event 1"
        },
        {
            "ingestionTime": 1433190516679,
            "timestamp": 1433190184356,
            "message": "Example Event 1"
        },
        {
            "ingestionTime": 1433190494190,
            "timestamp": 1433190184358,
            "message": "Example Event 2"
        }
    ],
    "nextBackwardToken": "b/31961209122358285602261756944988674324553373268216709120"
}

For more information, see Working with log groups and log streams in the Amazon CloudWatch Logs User Guide.

• For API details, see GetLogEvents in AWS CLI Command Reference.

put-log-events

The following code example shows how to use put-log-events.

AWS CLI

To put log events into a log stream

The following put-log-events example puts log events to a log stream named 20150601 in the log group my-logs. The command reads a JSON array of events from a file named events in the current directory.

aws logs put-log-events \
    --log-group-name my-logs \
    --log-stream-name 20150601 \
    --log-events file://events

Contents of events:

[
    {
        "timestamp": 1433190184356,
        "message": "Example Event 1"
    },
    {
        "timestamp": 1433190184358,
        "message": "Example Event 2"
    },
    {
        "timestamp": 1433190184360,
        "message": "Example Event 3"
    }
]

Output:

{
    "nextSequenceToken": "49542672486831074009579604567656788214806863282469607346"
}

Each subsequent call requires the next sequence token provided by the previous call to be specified with the sequence token option.

aws logs put-log-events \
    --log-group-name my-logs \
    --log-stream-name 20150601 \
    --log-events file://events2 \
    --sequence-token "49542672486831074009579604567656788214806863282469607346"

Contents of events2:

[
    {
        "timestamp": 1433190184362,
        "message": "Example Event 4"
    },
    {
        "timestamp": 1433190184364,
        "message": "Example Event 5"
    }
]

Output:

{
    "nextSequenceToken": "49542672486831074009579604567900991230369019956308219826"
}

For more information, see Working with log groups and log streams in the Amazon CloudWatch Logs User Guide.

• For API details, see PutLogEvents in AWS CLI Command Reference.

put-retention-policy

The following code example shows how to use put-retention-policy.

AWS CLI

To set the retention policy of a log group

The following put-retention-policy example adds a 5 day retention policy to a log group named my-logs.

aws logs put-retention-policy \
    --log-group-name my-logs \
    --retention-in-days 5

This command produces no output.

For more information, see Working with log groups and log streams in the Amazon CloudWatch Logs User Guide.

• For API details, see PutRetentionPolicy in AWS CLI Command Reference.

start-live-tail

The following code example shows how to use start-live-tail.

AWS CLI

To start a Live Tail session on a log group

The following start-live-tail example starts a Live Tail session on a log group named my-logs.

aws logs start-live-tail \
    --log-group-identifiers arn:aws:logs:us-west-2:123456789012:log-group:my-logs

Output:

INFO Processing request a1b2c3d4-5678-90ab-cdef-EXAMPLE11111
INFO Request a1b2c3d4-5678-90ab-cdef-EXAMPLE11111 completed in 120 ms

The following command starts a Live Tail session on a log group named my-logs in interactive mode.

aws logs start-live-tail \
    --log-group-identifiers arn:aws:logs:us-west-2:123456789012:log-group:my-logs \
    --mode interactive

This command produces no output. It displays an interactive Live Tail session in the terminal.

In interactive mode you can highlight as many as five terms in the tailed logs. The severity codes are highlighted by default. Press h to enter the highlight mode and then type in the terms to be highlighted, one at a time, and press enter. Press c to clear the highlighted term(s). Press t to toggle formatting between JSON/Plain text. Press Esc to exit the Live Tail session. Press up / down keys to scroll up or down between log events, use Ctrl + u / Ctrl + d to scroll faster. Press q to scroll to latest log events.

For more information, see Troubleshoot with CloudWatch Logs Live Tail in the Amazon CloudWatch Logs User Guide.

• For API details, see StartLiveTail in AWS CLI Command Reference.