is that a simile or a metaphor
Your statement is a simile. However, please remember that a simile is a metaphor, but not all metaphors are similes. When something is like something else, it is a simile. A metaphor is often more descriptive or it alludes to the subject with which it is compared. An example of a metaphor would be "Barbara's stomach growled reminiscent of a starving stallion kept too long in the paddock".