roachtest: add an early check in cluster-init

Release note: None

pkg/cmd/roachtest/cluster.go

@@ -1940,11 +1940,15 @@ func (m *monitor) wait(args ...string) error {
 }
 
 func waitForFullReplication(t *test, db *gosql.DB) {
+	tStart := timeutil.Now()
 	for ok := false; !ok; time.Sleep(time.Second) {
 		if err := db.QueryRow(
 			"SELECT min(array_length(replicas, 1)) >= 3 FROM crdb_internal.ranges",
 		).Scan(&ok); err != nil {
 			t.Fatal(err)
 		}
+		if timeutil.Since(tStart) > 30*time.Second {
+			t.l.Printf("still waiting for full replication")
+		}
 	}
 }

pkg/cmd/roachtest/cluster_init.go

@@ -34,6 +34,13 @@ func runClusterInit(ctx context.Context, t *test, c *cluster) {
 
 	addrs := c.InternalAddr(ctx, c.All())
 
+	// TODO(tbg): this should never happen, but I saw it locally. The result
+	// is the test hanging forever, because all nodes will create their own
+	// single node cluster and waitForFullReplication never returns.
+	if addrs[0] == "" {
+		t.Fatal("no address for first node")
+	}
+
 	// Legacy-style init where we start node 1 without a join flag and then point
 	// the other nodes at it.
 	func() {