Application outage Scenario using Krkn-hub
This scenario disrupts the traffic to the specified application to be able to understand the impact of the outage on the dependent service/user experience. Refer docs for more details.
Run
If enabling Cerberus to monitor the cluster and pass/fail the scenario post chaos, refer docs. Make sure to start it before injecting the chaos and set CERBERUS_ENABLED environment variable for the chaos injection container to autoconnect.
$ podman run --name=<container_name> --net=host --env-host=true -v <path-to-kube-config>:/home/krkn/.kube/config:Z -d quay.io/krkn-chaos/krkn-hub:application-outages
$ podman logs -f <container_name or container_id> # Streams Kraken logs
$ podman inspect <container-name or container-id> --format "{{.State.ExitCode}}" # Outputs exit code which can considered as pass/fail for the scenario
$ docker run $(./get_docker_params.sh) --name=<container_name> --net=host -v <path-to-kube-config>:/home/krkn/.kube/config:Z -d quay.io/krkn-chaos/krkn-hub:application-outages
OR
$ docker run -e <VARIABLE>=<value> --net=host -v <path-to-kube-config>:/home/krkn/.kube/config:Z -d quay.io/krkn-chaos/krkn-hub:application-outages
$ docker logs -f <container_name or container_id> # Streams Kraken logs
$ docker inspect <container-name or container-id> --format "{{.State.ExitCode}}" # Outputs exit code which can considered as pass/fail for the scenario
Tip
Because the container runs with a non-root user, ensure the kube config is globally readable before mounting it in the container. You can achieve this with the following commands:kubectl config view --flatten > ~/kubeconfig && chmod 444 ~/kubeconfig && docker run $(./get_docker_params.sh) --name=<container_name> --net=host -v ~kubeconfig:/home/krkn/.kube/config:Z -d quay.io/krkn-chaos/krkn-hub:<scenario>Supported parameters
The following environment variables can be set on the host running the container to tweak the scenario/faults being injected:
example:
export <parameter_name>=<value>
See list of variables that apply to all scenarios here that can be used/set in addition to these scenario specific variables
| Parameter | Description | Default |
|---|---|---|
| DURATION | Duration in seconds after which the routes will be accessible | 600 |
| NAMESPACE | Namespace to target - all application routes will go inaccessible if pod selector is empty ( Required ) | No default |
| POD_SELECTOR | Pods to target. For example “{app: foo}” | No default |
| BLOCK_TRAFFIC_TYPE | It can be Ingress or Egress or Ingress, Egress ( needs to be a list ) | [Ingress, Egress] |
Note
Defining theNAMESPACE parameter is required for running this scenario while the pod_selector is optional. In case of using pod selector to target a particular application, make sure to define it using the following format with a space between key and value: “{key: value}”.Note
In case of using custom metrics profile or alerts profile whenCAPTURE_METRICS or ENABLE_ALERTS is enabled, mount the metrics profile from the host on which the container is run using podman/docker under /home/krkn/kraken/config/metrics-aggregated.yaml and /home/krkn/kraken/config/alerts.$ podman run --name=<container_name> --net=host --env-host=true -v <path-to-custom-metrics-profile>:/home/krkn/kraken/config/metrics-aggregated.yaml -v <path-to-custom-alerts-profile>:/home/krkn/kraken/config/alerts -v <path-to-kube-config>:/home/krkn/.kube/config:Z -d quay.io/krkn-chaos/krkn-hub:application-outages
Demo
You can find a link to a demo of the scenario here