Logback Appender for Amazon CloudWatch

This is an asynchronous implementation of a Logback appender that writes events to a specified Amazon CloudWatch log group. It requires Java 8+ to compile.

The logger will fail if the matching log group is not found, but will attempt to create a missing log stream within the group. This is designed to allow the creation of per-instance streams based on dynamic parameters inside of a cluster. You could accomplish this by either supplying a property inside your log definition or using a streamNameSupplier to inject the correct stream at generation time.

Configuration Parameters

Name	Type	Purpose	Required?
encoder	Logback Encoder	describes a format for logged messages	yes
groupName	String	name of the CloudWatch log group	yes
streamName	String	name of the CloudWatch log stream	no^
streamNameSupplier	Supplier<String>	source for CloudWatch log stream names	no^
awsLogsSupplier	Supplier<AWSLogs>	source for a AWSLogs (CloudWatch) client	no

^ either a streamName or a streamNameSupplier must be provided

Sample Configuration

<appender name="AWS-CLOUD-WATCH" class="com.xpcagey.logback.CloudWatchAppender">
    <encoder>
        <pattern>%-5level [%.15thread] %logger{0}: %msg%n</pattern>
    </encoder>
    <groupName>MyGroup</groupName>
    <streamName>MyStream</streamName>
</appender>

Note that the timestamp is not present here because it is logged as an external field by CloudWatch. An example of a full file can be found in the integration tests here