Daemon
Enable Docker to run at login
See post-install instructions for details.
sudo systemctl enable docker
Start or stop the daemon
sudo systemctl stop docker
sudo systemctl start docker
sudo systemctl restart docker
Login
docker login
Unencrypted password will save to ~/.docker/config.json by default on Linux.
Refer to the docker-credential-pass guide for details on how to secure passwords.
For macOS, keychain integration is enabled when you install Docker.app.
Config
Inspect current config:
docker info
Important! Make sure “Docker Root Dir” is set outside of main partition for VMs with small local disks.
Enable large images
If you attempt to pull an image that is larger than 10 GB using the devicemapper storage driver, you may run into an error due to the current default configuration of the Docker daemon (dockerd) on Linux.
docker info &>2 > /dev/null | grep 'Base Device Size:'
docker info &>2 > /dev/null | grep 'Storage Driver:'
You can fix this by setting the default storage-opts for the Docker daemon. I recommend doing this with a JSON config file on Linux, which can be saved at /etc/docker/daemon.json.
Here’s a minimal configuration for the now deprecated devicemapper storage driver (still default on RHEL systems), increasing the default limit to 20 GB.
{
"storage-driver": "devicemapper",
"storage-opts": [
"dm.basesize=20G"
]
}
Image management
Force remove an image:
docker image rm --force "<IMAGE ID>"
Delete all dangling data (recommended):
docker system prune
Remove all images, not just dangling ones:
docker system prune --all --force