DNS Outage Scenarios

This scenario blocks all outgoing DNS traffic from a specific pod, effectively preventing it from resolving any hostnames or service names.

How to Run DNS Outage Scenarios

Choose your preferred method to run DNS outage scenarios:

Example scenario file: dns_outage.yml

Sample scenario config

- id: pod_network_filter
  wait_duration: 0
  test_duration: 60
  label_selector: ''
  service_account: ''
  namespace: 'default'
  instance_count: 1
  execution: parallel
  ingress: false
  egress: true
  target: <pod_name>
  interfaces: []
  ports: [53]
  taints: []
  protocols:
    - tcp
    - udp
  image: quay.io/krkn-chaos/krkn-network-chaos:latest

How to Use Plugin Name

Add the plugin name to the list of chaos_scenarios section in the config/config.yaml file

kraken:
    kubeconfig_path: ~/.kube/config                     # Path to kubeconfig
    ..
    chaos_scenarios:
        - network_chaos_ng_scenarios:
            - scenarios/<scenario_name>.yaml

Note

You can specify multiple scenario files of the same type by adding additional paths to the list:

kraken:
    chaos_scenarios:
        - network_chaos_ng_scenarios:
            - scenarios/dns-outage-1.yaml
            - scenarios/dns-outage-2.yaml
            - scenarios/dns-outage-3.yaml

You can also combine multiple different scenario types in the same config.yaml file. Scenario types can be specified in any order, and you can include the same scenario type multiple times:

kraken:
    chaos_scenarios:
        - network_chaos_ng_scenarios:
            - scenarios/dns-outage.yaml
        - pod_disruption_scenarios:
            - scenarios/pod-kill.yaml
        - container_scenarios:
            - scenarios/container-kill.yaml
        - network_chaos_ng_scenarios:  # Same type can appear multiple times
            - scenarios/dns-outage-2.yaml

Run

python run_kraken.py --config config/config.yaml

podman run -v ~/.kube/config:/home/krkn/.kube/config:z -e TEST_DURATION="60" \
    -e INGRESS="false" -e EGRESS="true" -e PROTOCOLS="tcp,udp" -e PORTS="53" \ 
    -e POD_NAME="target-pod" quay.io/krkn-chaos/krkn-hub:pod-network-filter

krknctl run pod-network-filter \
 --chaos-duration 60 \
 --pod-name target-pod \
 --ingress false \
 --egress true \
 --protocols tcp,udp \
 --ports 53