vault: Initial wan fed support (tls and gossip only)

acceptance/framework/helpers/helpers.go

@@ -148,3 +148,46 @@ func MergeMaps(a, b map[string]string) {
 		a[k] = v
 	}
 }
+
+// VerifyFederation checks that the WAN federation between servers is successful
+// by first checking members are alive from the perspective of both servers.
+// If secure is true, it will also check that the ACL replication is running on the secondary server.
+func VerifyFederation(t *testing.T, primaryClient, secondaryClient *api.Client, releaseName string, secure bool) {
+	retrier := &retry.Timer{Timeout: 5 * time.Minute, Wait: 1 * time.Second}
+	start := time.Now()
+
+	// Check that server in dc1 is healthy from the perspective of the server in dc2, and vice versa.
+	// We're calling the Consul health API, as opposed to checking serf membership status,
+	// because we need to make sure that the federated servers can make API calls and forward requests
+	// from one server to another. From running tests in CI for a while and using serf membership status before,
+	// we've noticed that the status could be "alive" as soon as the server in the secondary cluster joins the primary
+	// and then switch to "failed". This would require us to check that the status is "alive" is showing consistently for
+	// some amount of time, which could be quite flakey. Calling the API in another datacenter allows us to check that
+	// each server can forward calls to another, which is what we need for connect.
+	retry.RunWith(retrier, t, func(r *retry.R) {
+		secondaryServerHealth, _, err := primaryClient.Health().Node(fmt.Sprintf("%s-consul-server-0", releaseName), &api.QueryOptions{Datacenter: "dc2"})
+		require.NoError(r, err)
+		require.Equal(r, secondaryServerHealth.AggregatedStatus(), api.HealthPassing)
+
+		primaryServerHealth, _, err := secondaryClient.Health().Node(fmt.Sprintf("%s-consul-server-0", releaseName), &api.QueryOptions{Datacenter: "dc1"})
+		require.NoError(r, err)
+		require.Equal(r, primaryServerHealth.AggregatedStatus(), api.HealthPassing)
+
+		if secure {
+			replicationStatus, _, err := secondaryClient.ACL().Replication(nil)
+			require.NoError(r, err)
+			require.True(r, replicationStatus.Enabled)
+			require.True(r, replicationStatus.Running)
+		}
+	})
+
+	logger.Logf(t, "Took %s to verify federation", time.Since(start))
+}
+
+// MergeMaps will merge the values in b with values in a and save in a.
+// If there are conflicts, the values in b will overwrite the values in a.
+func MergeMaps(a, b map[string]string) {
+	for k, v := range b {
+		a[k] = v
+	}
+}