Docker Volumes

Table of contents

1. What is a Docker volume
2. Cases where Docker volume comes in handy
   1. You want some live-reloading features
   2. You want to persist data upon container shutdown

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What is a Docker volume

In short, it maps the volume inside a container with some local directory on your computer.

If you set the volume to read-only, every change in local directory will be reflected in the container but not vice versa.

If you set read-only to false, the contents inside the container and the local directory will remain same throughout the container execution.

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Cases where Docker volume comes in handy

You want some live-reloading features

During development, it is really painful if you have to rebuild or rerun everytime you make a change.

By mapping your container volume to a local build context, the container will update itself everytime you make a change to your local code.

You want to persist data upon container shutdown

For example if you’re running a DB as a container without a volume mapped, each time the container restarts, the contents of the DB will be erased.

However, if you map your container volume to a local directory, the data will be kept even after shutdown.