How to: Plugin Options
* `region`: The AWS region.
* `log_group_name`: The name of the CloudWatch Log Group that you want log records sent to. This value allows a template in the form of `$(variable)`. See section [Templating Log Group and Stream Names](#templating-log-group-and-stream-names) for more. Fluent Bit will create missing log groups if `auto_create_group` is set, and will throw an error if it does not have permission.
* `log_stream_name`: The name of the CloudWatch Log Stream that you want log records sent to. This value allows a template in the form of `$(variable)`. See section [Templating Log Group and Stream Names](#templating-log-group-and-stream-names) for more.
* `default_log_group_name`: This required variable is the fallback in case any variables in `log_group_name` fails to parse. Defaults to `fluentbit-default`.
* `default_log_stream_name`: This required variable is the fallback in case any variables in `log_stream_name` fails to parse. Defaults to `/fluentbit-default`.
* `log_stream_prefix`: (deprecated) Prefix for the Log Stream name. Setting this to `prefix-` is the same as setting `log_stream_name = prefix-$(tag)`.
* `log_key`: By default, the whole log record will be sent to CloudWatch. If you specify a key name with this option, then only the value of that key will be sent to CloudWatch. For example, if you are using the Fluentd Docker log driver, you can specify `log_key log` and only the log message will be sent to CloudWatch.
* `log_format`: An optional parameter that can be used to tell CloudWatch the format of the data. A value of `json/emf` enables CloudWatch to extract custom metrics embedded in a JSON payload. See the [Embedded Metric Format](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudWatch_Embedded_Metric_Format_Specification.html).
* `role_arn`: ARN of an IAM role to assume (for cross account access).
* `auto_create_group`: Automatically create log groups (and add tags). Valid values are "true" or "false" (case insensitive). Defaults to false. If you use dynamic variables in your log group name, you may need this to be `true`.
* `auto_create_stream`: Automatically create log streams. Valid values are "true" or "false" (case insensitive). Defaults to true.
* `new_log_group_tags`: Comma/equal delimited string of tags to include with _auto created_ log groups. Example: `"tag=val,cooltag2=my other value"`
* `log_retention_days`: If set to a number greater than zero, and newly create log group's retention policy is set to this many days.
* `endpoint`: Specify a custom endpoint for the CloudWatch Logs API.
* `sts_endpoint`: Specify a custom endpoint for the STS API; used to assume your custom role provided with `role_arn`.
* `credentials_endpoint`: Specify a custom HTTP endpoint to pull credentials from. The HTTP response body should look like the following:
```
{
    "AccessKeyId": "ACCESS_KEY_ID",
    "Expiration": "EXPIRATION_DATE",
    "SecretAccessKey": "SECRET_ACCESS_KEY",
    "Token": "SECURITY_TOKEN_STRING"
}
```

**Note**: The plugin will always create the log stream, if it does not exist.