Docker versions can be different depending on your configured build environment.

Also, in certain environments, you can manually configure which version of Docker to use.

When using the docker executor and setup_remote_docker configuration, you are given access to running docker commands from within your container.

You can configure setup_remote_docker to use a specific version by setting it as a version attribute.

For example:

To set a specific Docker version and review which versions are available, please see our documentation here.

To learn more about the Docker execution environment, please visit our documentation here.

When using the machine executor the available docker versions depend on which image you're using. You can see the available images and their included docker versions on this page.

Note: If you have any docker version needs outside of what is currently available, please open a feature request on our CircleCI Ideas page.