LPI 305-300 Exam With Confidence Using Practice Dumps

The WORKDIR instruction sets the working directory for any subsequent RUN, CMD, ENTRYPOINT, COPY and ADD instructions that follow it in the Dockerfile1. The RUN instruction executes commands in a new layer on top of the current image and commits the results2. The RUN cd command does not change the working directory for the next RUN instruction, because each RUN command runs in a new shell and a new environment3. Therefore, the file test is created in the root directory (/) of the container image, not in the /tmp directory. References:

Dockerfile reference: WORKDIR

Dockerfile reference: RUN

difference between RUN cd and WORKDIR in Dockerfile

Containerd is an industry-standard container runtime that uses Runc (a low-level container runtime) by default, but can be configured to use others as well1. Containerd manages the complete container lifecycle of its host system, from image transfer and storage to containerexecution and supervision1. It supports the standards established by the Open Container Initiative (OCI)1. Containerd does not require the Docker engine and Docker CLI to be installed, as it can be used independently or with other container platforms2. Containerd is not a text file format, nor does it run in each Docker container or provide DHCP client functionality. Containerd is not the initial process run at the start of any Docker container, as that is the role of the container runtime, such as Runc3. References: 1 (search for “containerd”), 2 (search for “Containerd is an open source”), 3 (search for “It uses rune to start containers”).

 The correct way to start a new container that shares the /data volume with the datastore container is to use the --volumes-from flag. This flag mounts all the defined volumes from the referenced containers. In this case, the datastore container has a volume named /data, which is mounted in the service container at the same path. The other options are incorrect because they either use invalid flags, such as --share-with or --volume-backend, or they create new volumes instead of sharing the existing one, such as -v datastore:/data or -v /data. References:

Docker Docs - Volumes

Stack Overflow - How to map volume paths using Docker’s --volumes-from?

Docker Docs - docker run