Add ability to select single node by prefix (#22)

- Update controller to be able to schedule a test to a single worker node via a nodename prefix.

README.md

@@ -41,6 +41,19 @@ spec:
     retries: 3
 ```
 
+#### Synthetic-test spec functionality
+
+Node selection:
+
+- `node: *`
+  - Run on all nodes
+- `node: worker*`
+  - Run on all nodes with the prefix 'worker'
+- `node: $`
+  - Run on a single (random) node
+- `node: worker$`
+  - Run on a single node with the prefix 'worker'
+
 ### The Agent
 
 ![Synthetic Heart Agent Architecture](./docs/agent_architecture.png)

chart/synthetic-heart/values.yaml

@@ -3,9 +3,9 @@
 controller:
   logLevel: INFO
   image:
-    repository: bakshi41c/synheart-controller
-    tag: "v1.2.1"
-    pullPolicy: Always
+    repository: localhost/synheart-controller
+    tag: "dev-latest"
+    pullPolicy: IfNotPresent
   ports:
     - containerPort: 2112 # For prometheus
       protocol: TCP
@@ -28,9 +28,9 @@ agent:
   printPluginLogs: onFail   # Whether to print logs of test runs (always, onFail, never)
   exportRate: 15s           # How often to export health status of plugins/agent
   image:
-    repository: bakshi41c/synheart-agent
-    tag: "v1.2.1-with-py"
-    pullPolicy: Always
+    repository: localhost/synheart-agent
+    tag: "dev-latest"
+    pullPolicy: IfNotPresent
   ports:
     - containerPort: 2112 # For prometheus
       protocol: TCP
@@ -60,9 +60,9 @@ agent:
 restapi:
   logLevel: INFO
   image:
-    repository: bakshi41c/synheart-restapi
-    tag: "v1.2.1"
-    pullPolicy: Always
+    repository: localhost/synheart-restapi
+    tag: "dev-latest"
+    pullPolicy: IfNotPresent
   annotations: {}
   ports:
     - containerPort: 8080

controller/internal/controller/synthetictest_controller.go

@@ -20,6 +20,11 @@ import (
 	"context"
 	"crypto/md5"
 	"fmt"
+	"math/rand/v2"
+	"os"
+	"strings"
+	"time"
+
 	"github.com/cisco-open/synthetic-heart/common"
 	"github.com/cisco-open/synthetic-heart/common/proto"
 	"github.com/cisco-open/synthetic-heart/common/storage"
@@ -33,15 +38,12 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/types"
-	"math/rand/v2"
-	"os"
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/event"
 	"sigs.k8s.io/controller-runtime/pkg/handler"
 	"sigs.k8s.io/controller-runtime/pkg/reconcile"
 	"sigs.k8s.io/controller-runtime/pkg/source"
-	"time"
 )
 
 // SyntheticTestReconciler reconciles a SyntheticTest object
@@ -106,7 +108,7 @@ func (r *SyntheticTestReconciler) Reconcile(ctx context.Context, request ctrl.Re
 	configId := common.ComputeSynTestConfigId(instance.Name, instance.Namespace)
 
 	// check if the test has the special key for node/pod assignment
-	needsNodeAssignment := instance.Spec.Node == "$"
+	needsNodeAssignment := strings.Contains(instance.Spec.Node, "$")
 	needsPodAssignment := false
 	if podNameVal, ok := instance.Spec.PodLabelSelector[common.SpecialKeyPodName]; ok && podNameVal == "$" {
 		needsPodAssignment = true
@@ -141,7 +143,7 @@ func (r *SyntheticTestReconciler) Reconcile(ctx context.Context, request ctrl.Re
 	if needsNodeAssignment || needsPodAssignment {
 		logger.Info("assigning agent for syntest", "name", instance.Name, "node", node, "podLabelSelector", podLabelSelector)
 		if needsNodeAssignment {
-			node = "" // set the node to blank
+			node = strings.ReplaceAll(node, "$", "*")
 		}
 		if needsPodAssignment {
 			delete(podLabelSelector, common.SpecialKeyPodName) // remove the special key for assignment