Kor - Kubernetes Orphaned Resources Finder

Kor is a tool to discover unused Kubernetes resources. Currently, Kor can identify and list unused:

• ConfigMaps
• Secrets
• Services
• ServiceAccounts
• Deployments
• StatefulSets
• Roles
• HPAs
• PVCs
• Ingresses
• PDBs
• CRDs
• PVs
• Pods
• Jobs

Installation

Download the binary for your operating system from the releases page and add it to your system's PATH.

Homebrew

For macOS users, you can install Kor using Homebrew:

brew install kor

Build from source

Install the binary to your $GOBIN or $GOPATH/bin:

go install github.com/yonahd/kor@latest

Docker

Run a container with your kubeconfig mounted:

docker run --rm -i yonahdissen/kor

docker run --rm -i -v "/path/to/.kube/config:/root/.kube/config" yonahdissen/kor all

Helm

Run as a cronjob in your Cluster (with an option for sending slack updates)

helm upgrade -i kor \
    --namespace kor \
    --create-namespace \
    --set cronJob.enabled=true
    ./charts/kor

Run as a deployment in your Cluster exposing prometheus metrics

helm upgrade -i kor \
    --namespace kor \
    --create-namespace \
    ./charts/kor

For more information see in cluster usage

Usage

Kor provides various subcommands to identify and list unused resources. The available commands are:

• all - Gets all unused resources for the specified namespace or all namespaces.
• configmap - Gets unused ConfigMaps for the specified namespace or all namespaces.
• secret - Gets unused Secrets for the specified namespace or all namespaces.
• services - Gets unused Services for the specified namespace or all namespaces.
• serviceaccount - Gets unused ServiceAccounts for the specified namespace or all namespaces.
• deployments - Gets unused Deployments for the specified namespace or all namespaces.
• statefulsets - Gets unused StatefulSets for the specified namespace or all namespaces.
• role - Gets unused Roles for the specified namespace or all namespaces.
• hpa - Gets unused HPAs for the specified namespace or all namespaces.
• pods - Gets unused Pods for the specified namespace or all namespaces.
• pvc - Gets unused PVCs for the specified namespace or all namespaces.
• pv - Gets unused PVs in the cluster(non namespaced resource).
• ingress - Gets unused Ingresses for the specified namespace or all namespaces.
• pdb - Gets unused PDBs for the specified namespace or all namespaces.
• crd - Gets unused CRDs in the cluster(non namespaced resource).
• jobs - Gets unused jobs for the specified namespace or all namespaces.
• exporter - Export Prometheus metrics.

Supported Flags

      --delete                      Delete unused resources
  -l, --exclude-labels string       Selector to filter out, Example: --exclude-labels key1=value1,key2=value2.
  -e, --exclude-namespaces string   Namespaces to be excluded, splited by comma. Example: --exclude-namespace ns1,ns2,ns3. If --include-namespace is set, --exclude-namespaces will be ignored.
  -h, --help                        help for kor
  -n, --include-namespaces string   Namespaces to run on, splited by comma. Example: --include-namespace ns1,ns2,ns3. 
  -k, --kubeconfig string           Path to kubeconfig file (optional)
      --newer-than string           The maximum age of the resources to be considered unused. This flag cannot be used together with older-than flag. Example: --newer-than=1h2m
      --no-interactive              Do not prompt for confirmation when deleting resources. Be careful using this flag!
      --older-than string           The minimum age of the resources to be considered unused. This flag cannot be used together with newer-than flag. Example: --older-than=1h2m
  -o, --output string               Output format (table, json or yaml) (default "table")
      --slack-auth-token string     Slack auth token to send notifications to. --slack-auth-token requires --slack-channel to be set.
      --slack-channel string        Slack channel to send notifications to. --slack-channel requires --slack-auth-token to be set.
      --slack-webhook-url string    Slack webhook URL to send notifications to
  -v, --verbose                     Verbose output (print empty namespaces)

To use a specific subcommand, run kor [subcommand] [flags].

kor all --include-namespaces my-namespace

For more information about each subcommand and its available flags, you can use the --help flag.

kor [subcommand] --help

Supported resources and limitations

Resource	What it looks for	Known False Positives ⚠️
ConfigMaps	ConfigMaps not used in the following places: - Pods - Containers - ConfigMaps used through Volumes - ConfigMaps used through environment variables	ConfigMaps used by resources which don't explicitly state them in the config. e.g Grafana dashboards loaded dynamically OPA policies fluentd configs
Secrets	Secrets not used in the following places: - Pods - Containers - Secrets used through volumes - Secrets used through environment variables - Secrets used by Ingress TLS - Secrets used by ServiceAccounts	Secrets used by resources which don't explicitly state them in the config
Services	Services with no endpoints
Deployments	Deployments with no Replicas
ServiceAccounts	ServiceAccounts unused by Pods ServiceAccounts unused by roleBinding or clusterRoleBinding
StatefulSets	Statefulsets with no Replicas
Roles	Roles not used in roleBinding
PVCs	PVCs not used in Pods
Ingresses	Ingresses not pointing at any Service
Hpas	HPAs not used in Deployments HPAs not used in StatefulSets
CRDs	CRDs not used the cluster
Pvs	PVs not bound to a PVC
Pdbs	PDBs not used in Deployments PDBs not used in StatefulSets
Jobs	Jobs status is completed

Deleting Unused resources

If you want to delete resources in an interactive way using Kor you can run:

kor configmap --include-namespaces my-namespace --delete

You will be prompted with:

Do you want to delete ConfigMap test-configmap in namespace my-namespace? (Y/N):

To delete with no prompt ( ⚠️ use with caution):

kor configmap --include-namespaces my-namespace --delete --no-interactive

Ignore Resources

The resources labeled with:

kor/used=true

will be ignored by kor even if they are unused. You can add this label to resources you want to ignore.

In Cluster Usage

To use this tool inside the cluster running as a CronJob and sending the results to a Slack Webhook as raw text(has characters limits of 4000) or to a Slack channel by uploading a file(recommended), you can use the following commands:

# Send to a Slack webhook as raw text
helm upgrade -i kor \
    --namespace kor \
    --create-namespace \
    --set cronJob.slackWebhookUrl=<slack-webhook-url> \
    ./charts/kor

# Send to a Slack channel by uploading a file
helm upgrade -i kor \
    --namespace kor \
    --create-namespace \
    --set cronJob.slackChannel=<slack-channel> \
    --set cronJob.slackToken=<slack-token> \
    ./charts/kor

Note: To send it to Slack as a file it's required to set the slackToken and slackChannel values.

It's set to run every Monday at 1 a.m. by default. You can change the schedule by setting the cronJob.schedule value.

helm upgrade -i kor \
    --namespace kor \
    --create-namespace \
    --set cronJob.slackChannel=<slack-channel> \
    --set cronJob.slackToken=<slack-token> \
    --set cronJob.schedule="0 1 * * 1" \
    ./charts/kor

Grafana Dashboard

Dashboard can be found here.

Contributing

Contributions are welcome! If you encounter any bugs or have suggestions for improvements, please open an issue in the issue tracker.

License

This open-source project is available under the MIT License. Feel free to use, modify, and distribute it as per the terms of the license.