ekristen/aws-nuke

package resources

import (
    "context"
    "strings"
    "time"

    "go.uber.org/ratelimit"

    "github.com/aws/aws-sdk-go/aws"
    "github.com/aws/aws-sdk-go/service/cloudwatchlogs"

    "github.com/ekristen/libnuke/pkg/registry"
    "github.com/ekristen/libnuke/pkg/resource"
    "github.com/ekristen/libnuke/pkg/types"

    "github.com/ekristen/aws-nuke/v3/pkg/nuke"
)

const CloudWatchLogsLogGroupResource = "CloudWatchLogsLogGroup"

func init() {
    registry.Register(&registry.Registration{
        Name:     CloudWatchLogsLogGroupResource,
        Scope:    nuke.Account,
        Resource: &CloudWatchLogsLogGroup{},
        Lister:   &CloudWatchLogsLogGroupLister{},
        DependsOn: []string{
            EC2VPCResource, // Reason: flow logs, if log group is cleaned before vpc, vpc can write more flow logs
        },
    })
}

type CloudWatchLogsLogGroupLister struct{}

func (l *CloudWatchLogsLogGroupLister) List(_ context.Context, o interface{}) ([]resource.Resource, error) {
    opts := o.(*nuke.ListerOpts)

    svc := cloudwatchlogs.New(opts.Session)
    resources := make([]resource.Resource, 0)

    // Note: these can be modified by the customer and account, and we could query them but for now we hard code
    // them to the bottom, because really it's per-second, and we should be fine querying at this rate for clearing
    // Ref: https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/cloudwatch_limits_cwl.html
    groupRl := ratelimit.New(10)
    streamRl := ratelimit.New(15)

    params := &cloudwatchlogs.DescribeLogGroupsInput{
        Limit: aws.Int64(50),
    }

    for {
        groupRl.Take() // Wait for DescribeLogGroup rate limiter

        output, err := svc.DescribeLogGroups(params)
        if err != nil {
            return nil, err
        }

        for _, logGroup := range output.LogGroups {
            streamRl.Take() // Wait for DescribeLogStream rate limiter

            arn := strings.TrimSuffix(*logGroup.Arn, ":*")
            tagResp, err := svc.ListTagsForResource(
                &cloudwatchlogs.ListTagsForResourceInput{
                    ResourceArn: &arn,
                })
            if err != nil {
                return nil, err
            }

            // get last event ingestion time
            lsResp, err := svc.DescribeLogStreams(&cloudwatchlogs.DescribeLogStreamsInput{
                LogGroupName: logGroup.LogGroupName,
                OrderBy:      aws.String("LastEventTime"),
                Limit:        aws.Int64(1),
                Descending:   aws.Bool(true),
            })
            if err != nil {
                return nil, err
            }

            var lastEvent time.Time
            if len(lsResp.LogStreams) > 0 && lsResp.LogStreams[0].LastIngestionTime != nil {
                lastEvent = time.Unix(*lsResp.LogStreams[0].LastIngestionTime/1000, 0)
            } else {
                lastEvent = time.Unix(*logGroup.CreationTime/1000, 0)
            }

            resources = append(resources, &CloudWatchLogsLogGroup{
                svc:       svc,
                logGroup:  logGroup,
                lastEvent: lastEvent.Format(time.RFC3339),
                tags:      tagResp.Tags,
            })
        }

        if output.NextToken == nil {
            break
        }

        params.NextToken = output.NextToken
    }

    return resources, nil
}

type CloudWatchLogsLogGroup struct {
    svc       *cloudwatchlogs.CloudWatchLogs
    logGroup  *cloudwatchlogs.LogGroup
    lastEvent string
    tags      map[string]*string
}

func (f *CloudWatchLogsLogGroup) Remove(_ context.Context) error {
    _, err := f.svc.DeleteLogGroup(&cloudwatchlogs.DeleteLogGroupInput{
        LogGroupName: f.logGroup.LogGroupName,
    })

    return err
}

func (f *CloudWatchLogsLogGroup) String() string {
    return *f.logGroup.LogGroupName
}

func (f *CloudWatchLogsLogGroup) Properties() types.Properties {
    properties := types.NewProperties().
        Set("logGroupName", f.logGroup.LogGroupName).
        Set("CreatedTime", f.logGroup.CreationTime).
        Set("LastEvent", f.lastEvent)

    for k, v := range f.tags {
        properties.SetTag(&k, v)
    }
    return properties
}