The RUN instruction will execute any commands in a new layer on top of the current image and commit the results.
the package are sorted in alphabetical order
RUN apt-get update && apt-get install -y \
package-bar \
package-baz \
package-foo
Pipe: set -o pipefail will fail the pipeline if one stage fails
RUN set -o pipefail && wget -O - https://some.site | wc -l > /number