feat(crd): update chaosexperiment schema (litmuschaos#13)

Updates the chaosexperiment custom resource schema to contain low-level chaos params eliminating need for chaosgraph

Signed-off-by: ksatchit <karthik.s@openebs.io>

deploy/crds/chaosexperiment.yaml

@@ -16,33 +16,54 @@ metadata:
 
   ## Eventually launched chaos litmusbook/job will bear <name>-<hash>
   name: pod-delete
-  namespace: nginx
   labels:
-    chart/type: kubernetes
-    chart/version: 0.9
+    litmuschaos.io/name: 
+    litmuschaos.io/instance: 
+    helm.sh/chart: 
 
 description:
   message: |
     Deletes a pod belonging to a deployment/statefulset/daemonset
-    a specified number of times 
+
 spec:
-
-  ## A predefined Chaos template type. Analogy: *Similar* in function to storage 
-  ## classes. Will contain params "specific" to that chaos operation w/ default values.
-  ## By default, the experiment is mapped to a chaosgraph of the same name, unless 
-  ## explicitly specified
-
-  # chaosgraph: 
+
+  ## A low-level definition of chaos parameters which is fed to the executor
+  ## for running the experiment.
 
   ## Some experiments need more info on the "object of chaos". For example, in case 
   ## of container crash tests in a multi-container app, it is necessary to know both 
   ## general app info (namespace, labels) as well as container name which has to undergo
-  ## failures. Component list can be kept to a minimum. 
+  ## failures. This Component info is generally kept to a minimum and passed as ENV to 
+  ## the actual chaos-runner/executor pod/container.  
+
+  definition:
+
+    labels: 
+      name: pod-delete
+
+    image: 
+
+    env:
+      - name: ANSIBLE_STDOUT_CALLBACK
+        value: ""
+
+      ## Injected by chaosengine 
+      - name: APP_NAMESPACE
+        value: ""              
+
+      ## Injected by chaosengine 
+      - name: APP_LABEL         
+        value: ""
+
+      - name: FORCE_DELETE
+        value: ""
+
+      ## The chaos operator can use different execution frameworks to achieve
+      ## to achieve a certain chaos operation. It could use Litmus or Chaostoolkit
+      ## etc..,
 
-  components:
-    container: ""    
-    nwinterface: ""
-    node: ""        
-    pvc: ""         
-    disk: ""        
+      - name: LIB
+        value: ""
 
+    command: ["/bin/bash"]
+    args: ["-c", "ansible-playbook ./experiments/chaos/pod_delete/test.yml -i /etc/ansible/hosts -vv; exit 0"]

pkg/apis/litmuschaos/v1alpha1/chaosexperiment_types.go

@@ -9,9 +9,8 @@ import (
 // An experiment is the definition of a chaos test and is listed as an item
 // in the chaos engine to be run against a given app.
 type ChaosExperimentSpec struct {
-        // ChaosGraph refers to the resource carrying low-level chaos options 
-        Chaosgraph    string                `json:"chaosgraph"`
-        Components    ComponentUnderTest    `json:"components"` 
+        // Definition carries low-level chaos options 
+        Definition    ExperimentDef         `json:"definition"`
 }
 
 // ChaosExperimentStatus defines the observed state of ChaosExperiment
@@ -22,18 +21,25 @@ type ChaosExperimentStatus struct {
 	// Add custom validation using kubebuilder tags: https://book.kubebuilder.io/beyond_basics/generating_crd.html
 }
 
-// ComponentUnderTest defines information about component subjected to chaos in an experiment
-type ComponentUnderTest struct {
-        //Name of container under test in a pod
-        Container      string               `json:"container"`
-        //Name of interface under test in a container 
-        NWinterface    string               `json:"nwinterface"`
-        //Name of node under test in a K8s cluster
-        Node           string               `json:"node"`
-        //Name of persistent volume claim used by app
-        PVC            string               `json:"pvc"`
-        //Name of backend disk under test on a node
-        Disk           string               `json:"disk"`
+// ExperimentDef defines information about nature of chaos & components subjected to it
+type ExperimentDef struct {
+        // Default labels of the executor pod
+        // +optional
+        Labels       map[string]string   `json:"labels"`
+        // Image of the chaos executor 
+        Image        string              `json:"image"`
+        // List of ENV vars passed to executor pod
+        ENVList      []ENVPair           `json:"env"`
+        // Defines command to invoke experiment
+        Command      []string            `json:"command"`
+        // Defines arguments to executor's entrypoint command
+        Args         []string            `json:"args"`
+}
+
+// ENVPair defines env var list to hold chaos params
+type ENVPair struct {
+        Name         string              `json:"name"`
+        Value        string              `json:"value"`
 }
 
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
@@ -43,7 +49,7 @@ type ComponentUnderTest struct {
 type ChaosExperiment struct {
 	metav1.TypeMeta   `json:",inline"`
 	metav1.ObjectMeta `json:"metadata,omitempty"`
-
+        
 	Spec   ChaosExperimentSpec   `json:"spec,omitempty"`
 	Status ChaosExperimentStatus `json:"status,omitempty"`
 }