Service Hijacking Scenario using Krkn-Hub

This scenario reroutes traffic intended for a target service to a custom web service that is automatically deployed by Krkn. This web service responds with user-defined HTTP statuses, MIME types, and bodies. For more details, please refer to the following documentation.

Run

Unlike other krkn-hub scenarios, this one requires a specific configuration due to its unique structure. You must set up the scenario in a local file following the scenario syntax, and then pass this file’s base64-encoded content to the container via the SCENARIO_BASE64 variable.

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> \
              -e SCENARIO_BASE64="$(base64 -w0 <scenario_file>)" \
              -v <path_to_kubeconfig>:/home/krkn/.kube/config:Z containers.krkn-chaos.dev/krkn-chaos/krkn-hub:service-hijacking
              
$ 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

Note

–env-host: This option is not available with the remote Podman client, including Mac and Windows (excluding WSL2) machines. Without the –env-host option you’ll have to set each enviornment variable on the podman command line like -e <VARIABLE>=<value>

$ export SCENARIO_BASE64="$(base64 -w0 <scenario_file>)"
$ docker run $(./get_docker_params.sh) --name=<container_name> \
                                       --net=host --pull=always \
                                       -v <path-to-kube-config>:/home/krkn/.kube/config:Z \
                                       -d containers.krkn-chaos.dev/krkn-chaos/krkn-hub:service-hijacking
OR 
$ docker run --name=<container_name> -e SCENARIO_BASE64="$(base64 -w0 <scenario_file>)" \
                                     --net=host --pull=always \
                                     -v <path-to-kube-config>:/home/krkn/.kube/config:Z \
                                     -d containers.krkn-chaos.dev/krkn-chaos/krkn-hub:service-hijacking

$ 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

ecause 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 --pull=always -v ~kubeconfig:/home/krkn/.kube/config:Z -d containers.krkn-chaos.dev/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
SCENARIO_BASE64	Base64 encoded service-hijacking scenario file. Note that the -w0 option in the command substitution `SCENARIO_BASE64="$(base64 -w0 <scenario_file>)"` is mandatory in order to remove line breaks from the base64 command output

A sample scenario file can be found here, you’ll need to customize it based on your wanted response codes for API calls

Note

In case of using custom metrics profile or alerts profile when CAPTURE_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.

For example:

$ podman run -e SCENARIO_BASE64="$(base64 -w0 <scenario_file>)" \
             --name=<container_name> \
             --net=host --pull=always \
             --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 containers.krkn-chaos.dev/krkn-chaos/krkn-hub:service-hijacking

Last modified August 29, 2025: adding service hijacking (a010f11)