Amazon CloudWatch Logs logging driver

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The awslogs logging driver sends container logs to Amazon CloudWatch Logs. Log entries can be retrieved through the AWS Management Console or the AWS SDKs and Command Line Tools.

Usage

You can configure the default logging driver by passing the --log-driver option to the Docker daemon:

dockerd --log-driver=awslogs

You can set the logging driver for a specific container by using the --log-driver option to docker run:

docker run --log-driver=awslogs ...

Amazon CloudWatch Logs options

You can use the --log-opt NAME=VALUE flag to specify Amazon CloudWatch Logs logging driver options.

awslogs-region

The awslogs logging driver sends your Docker logs to a specific region. Use the awslogs-region log option or the AWS_REGION environment variable to set the region. By default, if your Docker daemon is running on an EC2 instance and no region is set, the driver uses the instance’s region.

docker run --log-driver=awslogs --log-opt awslogs-region=us-east-1 ...

awslogs-group

You must specify a log group for the awslogs logging driver. You can specify the log group with the awslogs-group log option:

docker run --log-driver=awslogs --log-opt awslogs-region=us-east-1 --log-opt awslogs-group=myLogGroup ...

awslogs-stream

To configure which log stream should be used, you can specify the awslogs-stream log option. If not specified, the container ID is used as the log stream.

Note: Log streams within a given log group should only be used by one container at a time. Using the same log stream for multiple containers concurrently can cause reduced logging performance.

awslogs-create-group

Edge only: This option is only available in Docker CE Edge versions. See Docker CE Edge.

Log driver will return an error by default if the log group does not exist. However, you can set the awslogs-create-group to true to automatically create the log group as needed. The awslogs-create-group option defaults to false.

$ docker run --log-driver=awslogs \
             --log-opt awslogs-region=us-east-1 \
             --log-opt awslogs-group=myLogGroup \
             --log-opt awslogs-create-group=true \
             ...

Note: Your AWS IAM policy must include the logs:CreateLogGroup permission before you attempt to use awslogs-create-group.

tag

Specify tag as an alternative to the awslogs-stream option. tag interprets template markup (e.g., {{.ID}}, {{.FullID}} or {{.Name}} docker.{{.ID}}). See the tag option documentation for details on all supported template substitutions.

When both awslogs-stream and tag are specified, the value supplied for awslogs-stream will override the template specified with tag.

If not specified, the container ID is used as the log stream.

Note: The CloudWatch log API doesn’t support : in the log name. This can cause some issues when using the {{ .ImageName }} as a tag, since a docker image has a format of IMAGE:TAG, such as alpine:latest. Template markup can be used to get the proper format. To get the image name and the first 12 characters of the container id, you can use: --log-opt tag='{{ with split .ImageName ":" }}{{join . "_"}}{{end}}-{{.ID}}' the output will be something like: alpine_latest-bf0072049c76

Credentials

You must provide AWS credentials to the Docker daemon to use the awslogs logging driver. You can provide these credentials with the AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, and AWS_SESSION_TOKEN environment variables, the default AWS shared credentials file (~/.aws/credentials of the root user), or (if you are running the Docker daemon on an Amazon EC2 instance) the Amazon EC2 instance profile.

Credentials must have a policy applied that allows the logs:CreateLogStream and logs:PutLogEvents actions, as shown in the following example.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Action": [
        "logs:CreateLogStream",
        "logs:PutLogEvents"
      ],
      "Effect": "Allow",
      "Resource": "*"
    }
  ]
}
AWS, Amazon, CloudWatch, logging, driver