e2e: correction to assertions in system scheduler tests (#26875)

e2e/scheduler_system/input/system_canary_v1_100.nomad.hcl

@@ -17,7 +17,7 @@ job "system_job" {
       min_healthy_time = "1s"
       healthy_deadline = "1m"
       auto_revert      = false
-      canary           = 50
+      canary           = 100
     }
 
     restart {

e2e/scheduler_system/systemsched_test.go

@@ -5,6 +5,7 @@ package scheduler_system
 
 import (
 	"context"
+	"math"
 	"testing"
 	"time"
 
@@ -93,13 +94,17 @@ func testJobUpdateOnIneligbleNode(t *testing.T) {
 }
 
 func testCanaryUpdate(t *testing.T) {
-	_, cleanup := jobs3.Submit(t,
+	job, cleanup := jobs3.Submit(t,
 		"./input/system_canary_v0.nomad.hcl",
 		jobs3.DisableRandomJobID(),
 		jobs3.Timeout(60*time.Second),
 	)
 	t.Cleanup(cleanup)
 
+	// Get initial allocations
+	initialAllocs := job.Allocs()
+	must.SliceNotEmpty(t, initialAllocs)
+
 	// Update job
 	job2, cleanup2 := jobs3.Submit(t,
 		"./input/system_canary_v1.nomad.hcl",
@@ -109,19 +114,6 @@ func testCanaryUpdate(t *testing.T) {
 	)
 	t.Cleanup(cleanup2)
 
-	// how many eligible nodes do we have?
-	nodesApi := job2.NodesApi()
-	nodesList, _, err := nodesApi.List(nil)
-	must.Nil(t, err)
-	must.SliceNotEmpty(t, nodesList)
-
-	numberOfEligibleNodes := 0
-	for _, n := range nodesList {
-		if n.SchedulingEligibility == api.NodeSchedulingEligible {
-			numberOfEligibleNodes += 1
-		}
-	}
-
 	// Get updated allocations
 	allocs := job2.Allocs()
 	must.SliceNotEmpty(t, allocs)
@@ -152,7 +144,7 @@ func testCanaryUpdate(t *testing.T) {
 	})
 
 	// find allocations from v1 version of the job, they should all be canaries
-	// and there should be exactly 2
+	// and there should be exactly 50% (rounded up) of v0 allocations
 	count := 0
 	for _, a := range allocs {
 		if a.JobVersion == 1 {
@@ -160,7 +152,7 @@ func testCanaryUpdate(t *testing.T) {
 			count += 1
 		}
 	}
-	must.Eq(t, numberOfEligibleNodes/2, count, must.Sprint("expected canaries to be placed on 50% of eligible nodes"))
+	must.Eq(t, int(math.Ceil(float64(len(initialAllocs)/2))), count, must.Sprint("expected canaries to be placed on 50% of feasible nodes"))
 
 	// promote canaries
 	deployments, _, err := deploymentsApi.List(nil)
@@ -192,7 +184,7 @@ func testCanaryUpdate(t *testing.T) {
 	})
 
 	// expect the number of allocations for promoted deployment to be the same
-	// as the number of eligible nodes
+	// as the number of initial allocations
 	newAllocs := job2.Allocs()
 	must.SliceNotEmpty(t, newAllocs)
 
@@ -202,17 +194,21 @@ func testCanaryUpdate(t *testing.T) {
 			promotedAllocs += 1
 		}
 	}
-	must.Eq(t, numberOfEligibleNodes, promotedAllocs)
+	must.Eq(t, len(initialAllocs), promotedAllocs)
 }
 
 func testCanaryDeploymentToAllEligibleNodes(t *testing.T) {
-	_, cleanup := jobs3.Submit(t,
+	job, cleanup := jobs3.Submit(t,
 		"./input/system_canary_v0_100.nomad.hcl",
 		jobs3.DisableRandomJobID(),
 		jobs3.Timeout(60*time.Second),
 	)
 	t.Cleanup(cleanup)
 
+	// Get initial allocations
+	initialAllocs := job.Allocs()
+	must.SliceNotEmpty(t, initialAllocs)
+
 	// Update job
 	job2, cleanup2 := jobs3.Submit(t,
 		"./input/system_canary_v1_100.nomad.hcl",
@@ -228,13 +224,6 @@ func testCanaryDeploymentToAllEligibleNodes(t *testing.T) {
 	must.Nil(t, err)
 	must.SliceNotEmpty(t, nodesList)
 
-	numberOfEligibleNodes := 0
-	for _, n := range nodesList {
-		if n.SchedulingEligibility == api.NodeSchedulingEligible {
-			numberOfEligibleNodes += 1
-		}
-	}
-
 	// Get updated allocations
 	allocs := job2.Allocs()
 	must.SliceNotEmpty(t, allocs)
@@ -272,7 +261,7 @@ func testCanaryDeploymentToAllEligibleNodes(t *testing.T) {
 			count += 1
 		}
 	}
-	must.Eq(t, numberOfEligibleNodes, count, must.Sprint("expected canaries to be placed on all eligible nodes"))
+	must.Eq(t, len(initialAllocs), count, must.Sprint("expected canaries to be placed on all eligible nodes"))
 
 	// deployment must not be terminal and needs to have the right status
 	// description set