m/test/e2e: Implement TestE2ECoreHA

This is a basic test which exercises a TPM-sealed three-node cluster by
performing a rolling restart of control plane nodes.

Change-Id: Ic6f46192d8ccba1ef7a767988cf5a216beb5a4c6
Reviewed-on: https://review.monogon.dev/c/monogon/+/2884
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
Tested-by: Jenkins CI
diff --git a/metropolis/test/e2e/main_test.go b/metropolis/test/e2e/main_test.go
index 19df697..7004f7b 100644
--- a/metropolis/test/e2e/main_test.go
+++ b/metropolis/test/e2e/main_test.go
@@ -191,7 +191,72 @@
 	})
 }
 
-// TestE2ECore exercisees the Kubernetes functionality of Metropolis.
+// TestE2ECoreHA exercises the basics of a high-availability control plane by
+// starting up a 3-node cluster, turning all nodes into ConsensusMembers, then
+// performing a rolling restart.
+func TestE2ECoreHA(t *testing.T) {
+	// Set a global timeout to make sure this terminates
+	ctx, cancel := context.WithTimeout(context.Background(), globalTestTimeout)
+	defer cancel()
+
+	rPath, err := runfiles.Rlocation("_main/metropolis/test/e2e/testimages_manifest.prototxt")
+	if err != nil {
+		t.Fatalf("Resolving registry manifest failed: %v", err)
+	}
+	df, err := os.ReadFile(rPath)
+	if err != nil {
+		t.Fatalf("Reading registry manifest failed: %v", err)
+	}
+	lr, err := localregistry.FromBazelManifest(df)
+	if err != nil {
+		t.Fatalf("Creating test image registry failed: %v", err)
+	}
+	// Launch cluster.
+	clusterOptions := cluster.ClusterOptions{
+		NumNodes:        3,
+		LocalRegistry:   lr,
+		NodeLogsToFiles: true,
+	}
+	cluster, err := cluster.LaunchCluster(ctx, clusterOptions)
+	if err != nil {
+		t.Fatalf("LaunchCluster failed: %v", err)
+	}
+	defer func() {
+		err := cluster.Close()
+		if err != nil {
+			t.Fatalf("cluster Close failed: %v", err)
+		}
+	}()
+
+	launch.Log("E2E: Cluster running, starting tests...")
+
+	util.MustTestEventual(t, "Add ConsensusMember roles", ctx, smallTestTimeout, func(ctx context.Context) error {
+		// Make everything but the first node into ConsensusMember.
+		for i := 1; i < clusterOptions.NumNodes; i++ {
+			err := cluster.MakeConsensusMember(ctx, cluster.NodeIDs[i])
+			if err != nil {
+				return fmt.Errorf("MakeConsensusMember(%d/%s): %w", i, cluster.NodeIDs[i], err)
+			}
+		}
+		return nil
+	})
+	util.TestEventual(t, "Heartbeat test successful", ctx, 20*time.Second, cluster.AllNodesHealthy)
+
+	// Perform rolling restart of all nodes. When a node rejoins it must be able to
+	// contact the cluster, so this also exercises that the cluster is serving even
+	// with the node having rebooted.
+	for i := 0; i < clusterOptions.NumNodes; i++ {
+		util.MustTestEventual(t, fmt.Sprintf("Node %d rejoin successful", i), ctx, 60*time.Second, func(ctx context.Context) error {
+			// Ensure nodes rejoin the cluster after a reboot by reboting the 1st node.
+			if err := cluster.RebootNode(ctx, i); err != nil {
+				return fmt.Errorf("while rebooting a node: %w", err)
+			}
+			return nil
+		})
+	}
+}
+
+// TestE2EKubernetes exercises the Kubernetes functionality of Metropolis.
 //
 // The tests are performed against an in-memory cluster.
 func TestE2EKubernetes(t *testing.T) {