'Im not sure I understand the question.I assume you have a problem with the image layer caching and the RUN instruction is always invalidated. You can learn about image layer caching and Dockerfile optimization here:
I also edited your question.
Please, format your post next time according to the following guide: How to format your forum posts
In short: please, use </> button to share codes, terminal outputs, error messages or anything that can contain special characters which would be interpreted by the MarkDown filter. Use the preview feature to make sure your text is formatted as you would expect it and check your post after you have sent it so you can still fix it.
Example code block:
```
echo "I am a code."
echo "An athletic one, and I wanna run."
```