go beacon: change dummy entropy

This is so that we have more usable testing schedules with a compute-only
role and a merge-only role.

go/consensus/tendermint/apps/beacon/beacon.go

@@ -122,7 +122,19 @@ func (app *beaconApplication) onBeaconEpochChange(ctx *abci.Context, epoch epoch
 	case true:
 		// UNSAFE/DEBUG - Deterministic beacon.
 		entropyCtx = debugEntropyCtx
-		entropy = []byte("If you change this, you will fuck up the byzantine tests!!")
+		// We're setting this random seed so that we have
+		// suitable committee schedules for Byzantine E2E
+		// scenarios, where we want nodes to be scheduled for
+		// only one committee.
+		// The permutations derived from this on the first
+		// epoch need to have (i) an index that's compute
+		// worker only and (ii) an index that's merge worker
+		// only. See
+		// /go/oasis-test-runner/scenario/e2e/byzantine.go for
+		// the permutations generated from this seed.
+		// These permutations are generated independently of
+		// the deterministic node IDs.
+		entropy = []byte("luck=1")
 	}
 
 	b := getBeacon(epoch, entropyCtx, entropy)

go/oasis-test-runner/scenario/e2e/byzantine.go

@@ -14,6 +14,16 @@ import (
 // TODO: Consider referencing script names directly from the Byzantine node.
 
 var (
+	// Permutations generated in the epoch 1 election are
+	// compute:               0 (w), 1 (w), 2 (b), 3 (i)
+	// transaction scheduler: 2 (w), 3 (i), 1 (i), 0 (i)
+	// merge:                 1 (w), 3 (w), 2 (b), 0 (i)
+	// w = worker; b = backup; i = invalid
+	// For compute scripts, it suffices to be index 0.
+	// For merge scripts, it suffices to be index 3.
+	// No index is transaction scheduler only.
+	// Indices are by order of node ID.
+
 	// ByzantineComputeHonest is the byzantine compute honest scenario.
 	ByzantineComputeHonest scenario.Scenario = newByzantineImpl("compute-honest", nil, oasis.ByzantineDefaultIdentitySeed)
 	// ByzantineComputeWrong is the byzantine compute wrong scenario.
@@ -32,21 +42,21 @@ var (
 	}, oasis.ByzantineDefaultIdentitySeed)
 
 	// ByzantineMergeHonest is the byzantine merge honest scenario.
-	ByzantineMergeHonest scenario.Scenario = newByzantineImpl("merge-honest", nil, oasis.ByzantineDefaultIdentitySeed)
+	ByzantineMergeHonest scenario.Scenario = newByzantineImpl("merge-honest", nil, oasis.ByzantineIndex3IdentitySeed)
 	// ByzantineMergeWrong is the byzantine merge wrong scenario.
 	ByzantineMergeWrong scenario.Scenario = newByzantineImpl("merge-wrong", []log.WatcherHandlerFactory{
 		oasis.LogAssertNoTimeouts(),
 		oasis.LogAssertNoRoundFailures(),
 		oasis.LogAssertNoComputeDiscrepancyDetected(),
 		oasis.LogAssertMergeDiscrepancyDetected(),
-	}, oasis.ByzantineDefaultIdentitySeed)
+	}, oasis.ByzantineIndex3IdentitySeed)
 	// ByzantineMergeStraggler is the byzantine merge straggler scenario.
 	ByzantineMergeStraggler scenario.Scenario = newByzantineImpl("merge-straggler", []log.WatcherHandlerFactory{
 		oasis.LogAssertTimeouts(),
 		oasis.LogAssertNoRoundFailures(),
 		oasis.LogAssertNoComputeDiscrepancyDetected(),
 		oasis.LogAssertMergeDiscrepancyDetected(),
-	}, oasis.ByzantineDefaultIdentitySeed)
+	}, oasis.ByzantineIndex3IdentitySeed)
 )
 
 type byzantineImpl struct {