Following node chaos scenarios are supported:
- node_start_scenario: scenario to stop the node instance.
- node_stop_scenario: scenario to stop the node instance.
- node_stop_start_scenario: scenario to stop and then start the node instance.
- node_termination_scenario: scenario to terminate the node instance.
- node_reboot_scenario: scenario to reboot the node instance.
- stop_kubelet_scenario: scenario to stop the kubelet of the node instance.
- stop_start_kubelet_scenario: scenario to stop and start the kubelet of the node instance.
- node_crash_scenario: scenario to crash the node instance.
- stop_start_helper_node_scenario: scenario to stop and start the helper node and check service status.
NOTE: If the node doesn't recover from the node_crash_scenario injection, reboot the node to get it back to Ready state.
NOTE: node_start_scenario, node_stop_scenario, node_stop_start_scenario, node_termination_scenario, node_reboot_scenario and stop_start_kubelet_scenario are supported only on AWS, Azure, OpenStack, BareMetal and GCP as of now.
NOTE: Node scenarios are supported only when running the standalone version of Kraken until krkn-chaos#106 gets fixed.
How to set up AWS cli to run node scenarios is defined here
NOTE: Baremetal requires setting the IPMI user and password to power on, off, and reboot nodes, using the config options bm_user and bm_password. It can either be set in the root of the entry in the scenarios config, or it can be set per machine.
If no per-machine addresses are specified, kraken attempts to use the BMC value in the BareMetalHost object. To list them, you can do 'oc get bmh -o wide --all-namespaces'. If the BMC values are blank, you must specify them per-machine using the config option 'bmc_addr' as specified below.
For per-machine settings, add a "bmc_info" section to the entry in the scenarios config. Inside there, add a configuration section using the node name. In that, add per-machine settings. Valid settings are 'bmc_user', 'bmc_password', and 'bmc_addr'. For examples, see the example node scenario or the example below.
NOTE: Baremetal requires oc (openshift client) be installed on the machine running Kraken.
NOTE: Baremetal machines are fragile. Some node actions can occasionally corrupt the filesystem if it does not shut down properly, and sometimes the kubelet does not start properly.
How to set up GCP cli to run node scenarios is defined here
How to set up Openstack cli to run node scenarios is defined here
The supported node level chaos scenarios on an OPENSTACK cloud are node_stop_start_scenario, stop_start_kubelet_scenario and node_reboot_scenario.
NOTE: For stop_start_helper_node_scenario, visit here to learn more about the helper node and its usage.
To execute the scenario, ensure the value for ssh_private_key in the node scenarios config file is set with the correct private key file path for ssh connection to the helper node. Ensure passwordless ssh is configured on the host running Kraken and the helper node to avoid connection errors.
How to set up Azure cli to run node scenarios is defined here
NOTE: The node_crash_scenario and stop_kubelet_scenario scenario is supported independent of the cloud platform.
Use 'generic' or do not add the 'cloud_type' key to your scenario if your cluster is not set up using one of the current supported cloud types
Node scenarios can be injected by placing the node scenarios config files under node_scenarios option in the kraken config. Refer to node_scenarios_example config file.
node_scenarios:
- actions: # node chaos scenarios to be injected
- node_stop_start_scenario
- stop_start_kubelet_scenario
- node_crash_scenario
node_name: # node on which scenario has to be injected
label_selector: node-role.kubernetes.io/worker # when node_name is not specified, a node with matching label_selector is selected for node chaos scenario injection
instance_count: 1 # Number of nodes to perform action/select that match the label selector
runs: 1 # number of times to inject each scenario under actions (will perform on same node each time)
timeout: 120 # duration to wait for completion of node scenario injection
cloud_type: aws # cloud type on which Kubernetes/OpenShift runs
- actions:
- node_reboot_scenario
node_name:
label_selector: node-role.kubernetes.io/infra
instance_count: 1
timeout: 120
cloud_type: azure
- actions:
- node_crash_scenario
node_name:
label_selector: node-role.kubernetes.io/infra
instance_count: 1
timeout: 120
- actions:
- stop_start_helper_node_scenario # node chaos scenario for helper node
instance_count: 1
timeout: 120
helper_node_ip: # ip address of the helper node
service: # check status of the services on the helper node
- haproxy
- dhcpd
- named
ssh_private_key: /root/.ssh/id_rsa # ssh key to access the helper node
cloud_type: openstack
- actions:
- node_stop_start_scenario
node_name:
label_selector: node-role.kubernetes.io/worker
instance_count: 1
timeout: 120
cloud_type: bm
bmc_user: defaultuser # For baremetal (bm) cloud type. The default IPMI username. Optional if specified for all machines.
bmc_password: defaultpass # For baremetal (bm) cloud type. The default IPMI password. Optional if specified for all machines.
bmc_info: # This section is here to specify baremetal per-machine info, so it is optional if there is no per-machine info.
node-1: # The node name for the baremetal machine
bmc_addr: mgmt-machine1.example.com # Optional. For baremetal nodes with the IPMI BMC address missing from 'oc get bmh'
node-2:
bmc_addr: mgmt-machine2.example.com
bmc_user: user # The baremetal IPMI user. Overrides the default IPMI user specified above. Optional if the default is set.
bmc_password: pass # The baremetal IPMI password. Overrides the default IPMI user specified above. Optional if the default is set.