Learning Docker - Second Edition

The undesirable effect of data volume

As mentioned earlier, Docker enables access for us to each data volume in a Docker image using the VOLUME instruction during the build time. Nevertheless, data volumes should never be used to store any data during the build time, otherwise it will result in an unwanted effect.

In this section, we will demonstrate the undesirable effect of using data volume during the build by crafting a Dockerfile, and then showcase the implication by building this Dockerfile.

The following are the details of Dockerfile:

1. Build the image using Ubuntu 16.04 as the base image:

      # Use Ubuntu as the base image       FROM ubuntu:16.04 

2. Create a /MountPointDemo data volume using the VOLUME instruction:

 VOLUME /MountPointDemo ...