These kind of poor examples lead to a huge amount of waste when using Docker because people learning it are not taught about how layers interact, leading to ridiculous things like 'COPY' followed by 'RUN chown'.
Layers are a _core_ part of how Docker works, why not make this example "correct" by doing:
> RUN apk --no-cache add chromium chromium-chromedriver
Then just a comment like this: "it's important to group layers if possible to reduce your image size. By using `--no-cache` apk will update at the same time as installing".
> RUN apk update
> RUN apk add chromium chromium-chromedriver
These kind of poor examples lead to a huge amount of waste when using Docker because people learning it are not taught about how layers interact, leading to ridiculous things like 'COPY' followed by 'RUN chown'.
Layers are a _core_ part of how Docker works, why not make this example "correct" by doing:
> RUN apk --no-cache add chromium chromium-chromedriver
Then just a comment like this: "it's important to group layers if possible to reduce your image size. By using `--no-cache` apk will update at the same time as installing".