consul/state: basic session destroy works

consul/state/state_store.go

@@ -1138,3 +1138,44 @@ func (s *StateStore) NodeSessions(nodeID string) (uint64, []*structs.Session, er
 	}
 	return lindex, result, nil
 }
+
+// SessionDestroy is used to remove an active session. This will
+// implicitly invalidate the session and invoke the specified
+// session destroy behavior.
+func (s *StateStore) SessionDestroy(idx uint64, sessionID string) error {
+	tx := s.db.Txn(true)
+	defer tx.Abort()
+
+	// Call the session deletion
+	if err := s.sessionDestroyTxn(idx, sessionID, tx); err != nil {
+		return err
+	}
+
+	tx.Commit()
+	return nil
+}
+
+// sessionDestroyTxn is the inner method, which is used to do the actual
+// session deletion and handle session invalidation, watch triggers, etc.
+func (s *StateStore) sessionDestroyTxn(idx uint64, sessionID string, tx *memdb.Txn) error {
+	// Look up the session
+	sess, err := tx.First("sessions", "id", sessionID)
+	if err != nil {
+		return fmt.Errorf("failed session lookup: %s", err)
+	}
+	if sess == nil {
+		return nil
+	}
+
+	// Delete the session and write the new index
+	if err := tx.Delete("sessions", sess); err != nil {
+		return fmt.Errorf("failed deleting session: %s", err)
+	}
+	if err := tx.Insert("index", &IndexEntry{"sessions", idx}); err != nil {
+		return fmt.Errorf("failed updating index: %s", err)
+	}
+
+	// TODO: invalidate session
+
+	return nil
+}

consul/state/state_store_test.go

@@ -1431,3 +1431,49 @@ func TestStateStore_NodeSessions(t *testing.T) {
 		t.Fatalf("bad: %#v", res)
 	}
 }
+
+func TestStateStore_SessionDestroy(t *testing.T) {
+	s := testStateStore(t)
+
+	// Session destroy is idempotent and returns no error
+	// if the session doesn't exist.
+	if err := s.SessionDestroy(1, "nope"); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Ensure the index was not updated if nothing was destroyed
+	if idx := s.maxIndex("sessions"); idx != 0 {
+		t.Fatalf("bad index: %d", idx)
+	}
+
+	// Register a node
+	testRegisterNode(t, s, 1, "node1")
+
+	// Register a new session
+	sess := &structs.Session{
+		ID:   "session1",
+		Node: "node1",
+	}
+	if err := s.SessionCreate(2, sess); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Destroy the session
+	if err := s.SessionDestroy(3, "session1"); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	tx := s.db.Txn(false)
+	defer tx.Abort()
+
+	// Make sure the session is really gone
+	sessions, err := tx.Get("sessions", "id")
+	if err != nil || sessions.Next() != nil {
+		t.Fatalf("session should not exist")
+	}
+
+	// Check that the index was updated
+	if idx := s.maxIndex("sessions"); idx != 3 {
+		t.Fatalf("bad index: %d", idx)
+	}
+}