DockerFile - Run command

About

The RUN instruction will execute any commands in a new layer on top of the current image and commit the results.

Example

How to run a script without copying it

With the –mount option ¹⁾, you don't need to copy executing script and dependencies into the image layers.

Example:

RUN --mount=target=/build /build/setup.sh

where:

• –mount=target=/build is mounting the Docker context into the /build directory of the build image.
• /build/setup.sh is the executing command

Tool installation

RUN apt-get update && apt-get install -y \
        package-bar \
        package-baz \
        package-foo

Pipeline error handling

Pipe: set -o pipefail will fail the pipeline if one stage fails

RUN set -o pipefail && wget -O - https://some.site | wc -l > /number

Documentation / Reference

• https://docs.docker.com/engine/reference/builder/#run