func GetLogsSince()

in util/awsservice/cloudwatchlogs.go [79:134]
39 lines of code
12 McCabe index (conditional complexity)

func GetLogsSince(logGroup, logStream string, since, until *time.Time) ([]types.OutputLogEvent, error) {
	var events []types.OutputLogEvent

	// https://docs.aws.amazon.com/AmazonCloudWatchLogs/latest/APIReference/API_GetLogEvents.html
	// GetLogEvents can return an empty result while still having more log events on a subsequent page,
	// so rather than expecting all the events to show up in one GetLogEvents API call, we need to paginate.
	params := &cloudwatchlogs.GetLogEventsInput{
		LogGroupName:  aws.String(logGroup),
		LogStreamName: aws.String(logStream),
		StartFromHead: aws.Bool(true), // read from the beginning
	}

	if since != nil {
		params.StartTime = aws.Int64(since.UnixMilli())
	}

	if until != nil {
		params.EndTime = aws.Int64(until.UnixMilli())
	}

	var nextToken *string
	attempts := 0

	for {
		if nextToken != nil {
			params.NextToken = nextToken
		}
		output, err := CwlClient.GetLogEvents(ctx, params)

		attempts += 1

		if err != nil {
			if errors.As(err, &rnf) && attempts <= StandardRetries {
				// The log group/stream hasn't been created yet, so wait and retry
				time.Sleep(30 * time.Second)
				continue
			}

			// if the error is not a ResourceNotFoundException, we should fail here.
			return events, err
		}

		for _, e := range output.Events {
			events = append(events, e)
		}

		if nextToken != nil && output.NextForwardToken != nil && *output.NextForwardToken == *nextToken {
			// From the docs: If you have reached the end of the stream, it returns the same token you passed in.
			log.Printf("Done paginating log events for %s/%s and found %d logs", logGroup, logStream, len(events))
			break
		}

		nextToken = output.NextForwardToken
	}
	return events, nil
}