Don't follow the 'active verbs' rule too much. There's a limit to it, especially when writing technical documents. If it sounds unnatural, or when you have an implied subject that's an important part of the thing you're trying to convey, just use passive voice.
TFA does mention some good uses of passive voice. If I were to add one more example it would be where the object is actually more important than the subject. "The handle then gets closed by one of the cleanup mechanisms" is probably okay if you are telling the story of the handle.