Installing Docker

To install Docker on a server running Oracle Linux 8, some special configuration is needed. Much of this comes from the official documentation.

Prerequisites

First, make sure that Docker isn’t already installed:

yum list installed | grep docker

Remove any existing installations before proceeding.

Ensure that /opt (or whatever disk is to be used for Docker data) is formatted with the d_type option. You can find out like this:

$ xfs_info /opt
meta-data=/dev/mapper/vg0-lv_opt isize=512    agcount=4, agsize=5701632 blks
         =                       sectsz=4096  attr=2, projid32bit=1
         =                       crc=1        finobt=0 spinodes=0
data     =                       bsize=4096   blocks=22806528, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal               bsize=4096   blocks=11136, version=2
         =                       sectsz=4096  sunit=1 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

If the above says ftype=0, then the filesystem will need to be recreated (reference).

Installing Docker

sudo yum install -y yum-utils
sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
sudo yum install -y docker-ce

If this fails with error messages like package containerd.io-1.4.3-3.2.el8.x86_64 conflicts with runc provided by runc then you may have conflicting packages installed already. Try removing them like this:

sudo yum erase podman buildah

Post Install Configuration

To avoid running out of space on the root partition, you should configure docker to point to /opt/docker (reference):

sudo mkdir -p /opt/docker
sudo chown root:root /opt/docker
sudo chmod 701 /opt/docker

Next, configure Docker to use the overlay2 storage driver (reference).

Create a file at /etc/docker/daemon.json with this content:

{
  "data-root": "/opt/docker",
  "storage-driver": "overlay2"
}

You should also create a local user called “docker-nobody” with UID 4444, which can be used for running containers without root.

sudo groupadd -g 4444 docker-nobody
sudo useradd --uid 4444 --gid 4444 --shell /sbin/nologin docker-nobody

Finally, you can start Docker:

sudo systemctl enable docker
sudo systemctl start docker

Installing Docker Compose

You’ll also need to install the Docker Compose executable:

sudo curl -L "https://github.com/docker/compose/releases/download/1.23.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
sudo chmod +x /usr/local/bin/docker-compose

Note that there are newer versions of the Docker Compose, but they have bugs that prevent them from working with our scripts. Please use the version above to ensure compatibility.