dnscollector

README

IP Address and DNS Record Garbage Collector

Overview

This command finds and removes orphaned IP Addresses and related DNS records created by GKE integration jobs in a Google Cloud Platform (GCP) project.

When an integration job installs Kyma on a GKE cluster, it reserves the required IP addresses and adds necessary DNS records. Usually, the job that provisions the cluster cleans up the resources once they are not needed. It can happen, however, that the job cleanup process fails. This causes a resource leak that generates unwanted costs. The garbage collector finds and removes unused IP addresses and related DNS records.

There are three conditions used to find IP address for removal:

• The address name pattern that is specific for the given GKE integration job
• The status of the IP address shows it is not in use (this value is not configurable by the user)
• The address creationTimestamp value that is used to find addresses existing at least for a preconfigured number of hours

Addresses that meet these conditions are subject to removal. Before removal of a matching address, the command finds all DNS records associated with the IP address. The command removes all associated DNS records first, then the IP Address.

Usage

For safety reasons, the dry-run mode is the default one. To run it, use:

env GOOGLE_APPLICATION_CREDENTIALS={path to service account file} go run main.go \
    --project={gcloud project name} --dnsZone={gcloud managed zone name} \
    --regions={list of GCP regions}

To turn the dry-run mode off, use:

env GOOGLE_APPLICATION_CREDENTIALS={path to service account file} go run main.go \
    --project={gcloud project name} --dnsZone={gcloud managed zone name} \
    --regions={list of GCP regions} --dryRun=false

Flags

See the list of available flags:

Name	Required	Description
--project	Yes	GCP project name.
--regions	Yes	GCP region name or a comma-separated list of such values.
--dnsZone	Yes	GCP DNS Managed Zone name used to lookup of DNS records for removal.
--dryRun	No	The boolean value that controls the dry-run mode. It defaults to true.
--ageInHours	No	The integer value for the number of hours. It only matches addresses older than now()-ageInHours. It defaults to 2.
--addressRegexpList	No	The string value with a Golang regexp or a comma-separated list of such expressions. It is used to match addresses by their name. It defaults to `(remoteenvs-)?gkeint-(pr

Environment variables

See the list of available environment variables:

Name	Required	Description
GOOGLE_APPLICATION_CREDENTIALS	Yes	The path to the service account file. The service account requires at least compute.addresses.list, compute.addresses.delete, dns.resourceRecordSets.list, and dns.changes.create Google IAM permissions.