fix: random orchestrator uses repeatable random seed

Author: gschueler

plugins/orchestrator-plugin/src/main/java/org/rundeck/plugin/example/MaxPercentageOrchestator.java

@@ -36,7 +36,7 @@ public class MaxPercentageOrchestator implements Orchestrator {
 
 
     public MaxPercentageOrchestator(StepExecutionContext context, Collection<INodeEntry> nodes, int percentage) {
-        this.list = new ArrayList<INodeEntry>(nodes);
+        this.list = new ArrayList<>(nodes);
         percentage = validPercentage(percentage);
         this.max = calculateMax(nodes.size(), percentage);
         if (context != null) {

plugins/orchestrator-plugin/src/main/java/org/rundeck/plugin/example/RandomSubsetOrchestrator.java

@@ -31,11 +31,19 @@
  */
 public class RandomSubsetOrchestrator implements Orchestrator {
 
-    Random random = new Random(System.currentTimeMillis());
+    Random random;
+    long seed;
     final int count;
     List<INodeEntry> nodes;
 
-    public RandomSubsetOrchestrator(int count, StepExecutionContext context, Collection<INodeEntry> nodes) {
+    public RandomSubsetOrchestrator(
+            int count,
+            StepExecutionContext context,
+            Collection<INodeEntry> nodes, final long seed
+    )
+    {
+        this.seed = seed;
+        this.random = new Random(seed);
         this.count = count;
         this.nodes = select(count, nodes);
     }

plugins/orchestrator-plugin/src/main/java/org/rundeck/plugin/example/RandomSubsetOrchestratorPlugin.java

@@ -26,6 +26,8 @@
 import com.dtolabs.rundeck.plugins.orchestrator.OrchestratorPlugin;
 
 import java.util.Collection;
+import java.util.List;
+import java.util.stream.Collectors;
 
 @Plugin(name = "subset", service = ServiceNameConstants.Orchestrator)
 @PluginDescription(title = "Random Subset", description = "Chooses only a random subset of the target nodes.")
@@ -37,6 +39,22 @@ public class RandomSubsetOrchestratorPlugin implements OrchestratorPlugin {
 
     @Override
     public Orchestrator createOrchestrator(StepExecutionContext context, Collection<INodeEntry> nodes) {
-        return new RandomSubsetOrchestrator(count, context, nodes);
+        String ident = createWFLayerIdent(context);
+        //use the ident as random seed to allow repeatable sequence of random nodes
+        //if this orchestrator config is invoked more than once in the same
+        //workflow layer
+        return new RandomSubsetOrchestrator(count, context, nodes, (long) ident.hashCode());
+    }
+
+    public String createWFLayerIdent(final StepExecutionContext context) {
+        //create a string which identifies this execution layer uniquely
+        List<Integer> stepContext = context.getStepContext();
+        String ident = context.getFrameworkProject();
+        if (context.getDataContext().get("job") != null && context.getDataContext().get("job").get("execid") != null) {
+            ident += context.getDataContext().get("job").get("execid");
+        }
+
+        return ident +
+               String.join(",", stepContext.stream().map(Object::toString).collect(Collectors.toList()));
     }
 }