Fix flapping host network interfaces (#1283)

Ensure that host network interfaces do not disappear when they (unexpectedly)
are returned with no updates from osquery. Add test to verify.

Fixes #1278

server/datastore/datastore_hosts_test.go

@@ -625,3 +625,57 @@ func testMarkHostSeen(t *testing.T, ds kolide.Datastore) {
 		assert.WithinDuration(t, anHourAgo, h1Verify.SeenTime, time.Second)
 	}
 }
+
+func testFlappingNetworkInterfaces(t *testing.T, ds kolide.Datastore) {
+	// See https://github.com/kolide/kolide/issues/1278
+	host, err := ds.NewHost(&kolide.Host{
+		DetailUpdateTime: time.Now(),
+		SeenTime:         time.Now(),
+		NodeKey:          "1",
+		UUID:             "1",
+		HostName:         "foo.local",
+	})
+	require.Nil(t, err)
+	require.NotNil(t, host)
+
+	host.HostName = "bar.local"
+	err = ds.SaveHost(host)
+	require.Nil(t, err)
+
+	host, err = ds.Host(host.ID)
+	require.Nil(t, err)
+	assert.Equal(t, "bar.local", host.HostName)
+
+	host.NetworkInterfaces = []*kolide.NetworkInterface{
+		&kolide.NetworkInterface{
+			HostID:    host.ID,
+			Interface: "en0",
+			IPAddress: "98.99.100.101",
+		},
+	}
+
+	err = ds.SaveHost(host)
+	require.Nil(t, err)
+
+	host, err = ds.AuthenticateHost(host.NodeKey)
+	require.Nil(t, err)
+	assert.Len(t, host.NetworkInterfaces, 1)
+
+	// Simulate osquery returning the same results for the network
+	// interfaces (note it's important that we reset this so that the ID is
+	// 0 before saving)
+	host.NetworkInterfaces = []*kolide.NetworkInterface{
+		&kolide.NetworkInterface{
+			HostID:    host.ID,
+			Interface: "en0",
+			IPAddress: "98.99.100.101",
+		},
+	}
+
+	err = ds.SaveHost(host)
+	require.Nil(t, err)
+
+	host, err = ds.AuthenticateHost(host.NodeKey)
+	require.Nil(t, err)
+	assert.Len(t, host.NetworkInterfaces, 1)
+}

server/datastore/datastore_test.go

@@ -72,4 +72,5 @@ var testFunctions = [...]func(*testing.T, kolide.Datastore){
 	testChangeEmail,
 	testLicense,
 	testSaveLabel,
+	testFlappingNetworkInterfaces,
 }

server/datastore/mysql/hosts.go

@@ -71,6 +71,8 @@ func removedUnusedNics(tx *sqlx.Tx, host *kolide.Host) error {
 
 func updateNicsForHost(tx *sqlx.Tx, host *kolide.Host) ([]*kolide.NetworkInterface, error) {
 	updatedNics := []*kolide.NetworkInterface{}
+	// id = LAST_INSERT_ID(id) is a fix for the lastinsertid not being set
+	// properly. See comments in https://goo.gl/cwWRXd.
 	sqlStatement := `
 	 	INSERT INTO network_interfaces (
 			host_id,
@@ -92,6 +94,7 @@ func updateNicsForHost(tx *sqlx.Tx, host *kolide.Host) ([]*kolide.NetworkInterfa
 			type
 		) VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)
 		ON DUPLICATE KEY UPDATE
+			id = LAST_INSERT_ID(id),
 			mac = VALUES(mac),
 			broadcast = VALUES(broadcast),
 			ibytes = VALUES(ibytes),

server/datastore/mysql/migrations/tables/20170223094154_AddTimestampsToNetworkInterfaces.go

@@ -0,0 +1,25 @@
+package tables
+
+import "database/sql"
+
+func init() {
+	MigrationClient.AddMigration(Up_20170223094154, Down_20170223094154)
+}
+
+func Up_20170223094154(tx *sql.Tx) error {
+	_, err := tx.Exec(
+		"ALTER TABLE `network_interfaces` " +
+			"ADD COLUMN `created_at` timestamp DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, " +
+			"ADD COLUMN `updated_at` timestamp DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP",
+	)
+	return err
+}
+
+func Down_20170223094154(tx *sql.Tx) error {
+	_, err := tx.Exec(
+		"ALTER TABLE `network_interfaces` " +
+			"DROP COLUMN `created_at`, " +
+			"DROP COLUMN `updated_at`",
+	)
+	return err
+}

server/kolide/network_interfaces.go

@@ -1,6 +1,7 @@
 package kolide
 
 type NetworkInterface struct {
+	UpdateCreateTimestamps
 	ID uint `json:"id"`
 	// HostID foreign key establishes one host to many NetworkInterface relationship
 	HostID       uint   `json:"-" db:"host_id"`

server/service/service_osquery_test.go

@@ -225,7 +225,6 @@ func TestHostDetailQueries(t *testing.T) {
 }
 
 func TestLabelQueries(t *testing.T) {
-
 	ds, svc, mockClock := setupOsqueryTests(t)
 	ctx := context.Background()