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Installation + Configuration

This document will be focused on Linux but I have written some additional notes for Windows.

Installation

Installing Docker

sudo yum install docker
sudo systemctl start docker
sudo systemctl enable docker
sudo usermod -aG docker $USER

The setup of Docker is described in Post-installation steps for Linux.

Installing Docker Compose

sudo curl -L "https://github.com/docker/compose/releases/download/1.24.1/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
sudo chmod +x /usr/local/bin/docker-compose

The installation of Docker Compose is described in the Docker Docs.

Configuration

The Docker engine can be configured by tweaking /etc/docker/daemon.json.

This is can also be done through in Settings -> GUI (Advanced) on Docker for Windows

Here is my latest template for EC2 instances running Docker:

{
    "builder": {
        "gc": {
            "enabled": true,
            "policy": [
                {"keepStorage": "512MB", "filter": {"unused-for": {"168h": true}}},
                {"keepStorage": "2GB", "all": true}
            ]
        }
    },
    "features": {"buildkit": true},
    "log-driver": "local",
    "log-opts": {"max-size": "10m", "max-file": "3"},
    "no-new-privileges": true
}

BuildKit

Enable BuildKit as follows:

{
    "features": {"buildkit": true}
}

Logging

File Sizes

Limit the size of log files for new containers as follows:

{
    "log-opts": {"max-size": "10m", "max-file": "3"}
}

Log Driver

The local logging driver was introduced in Docker 18.09, released 2018-11-08.

Switch to the optimized driver for new containers as follows:

{
    "log-driver": "local"
}

Further Reading

Local File logging driver

Docker Reference Architecture: Docker Logging Design and Best Practices

Networking

Subnet Collisions

Avoid subnet collisions on other networks by using BIP and specifying default address pools:

{
    "bip": "10.15.0.1/24",
    "default-address-pools": [
        {"base": "10.20.0.0/16", "size": 24},
        {"base": "10.40.0.0/16", "size": 24}
    ]
}

Build Cache

You can specify the garbage collection policy in daemon.json:

{
    "builder": {
        "gc": {
            "enabled": true,
            "policy": [
                {"keepStorage": "512MB", "filter": {"unused-for": {"168h": true}}},
                {"keepStorage": "2GB", "all": true}
            ]
        }
    }
}

Orchestration

Auto-Start Containers

Containers can be started automatically by setting their restart policy.

This is explained in the Docker documentation - Start containers automatically.

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