Docker Daemon Configuration

$ cat /usr/lib/systemd/system/docker.service
[Unit]
Description=Docker Application Container Engine
Documentation=http://docs.docker.com
After=network.target
Wants=docker-storage-setup.service

[Service]
LimitMEMLOCK=1288490188800
LimitSTACK=infinity
LimitNPROC=infinity
LimitNOFILE=1310720
LimitCORE=infinity
Type=notify
EnvironmentFile=-/etc/sysconfig/docker
EnvironmentFile=-/etc/sysconfig/docker-storage
EnvironmentFile=-/etc/sysconfig/docker-network
Environment=GOTRACEBACK=crash
ExecStart=/usr/bin/docker daemon $OPTIONS \
          $DOCKER_CERT \
          $DEFAULT_ULIMIT \
          $DOCKER_STORAGE_OPTIONS \
          $DOCKER_NETWORK_OPTIONS \
          $ADD_REGISTRY \
          $BLOCK_REGISTRY \
          $INSECURE_REGISTRY
MountFlags=slave
TimeoutStartSec=1min
Restart=on-failure

[Install]
WantedBy=multi-user.target

$ cat /etc/sysconfig/docker
# /etc/sysconfig/docker

# Modify these options if you want to change the way the docker daemon runs
OPTIONS='--disable-legacy-registry --log-opt max-size=2m --log-opt max-file=5 --log-level=warn'
DEFAULT_ULIMIT='--default-ulimit nofile=131072 --default-ulimit memlock=131941395333120 --default-ulimit core=-1 --default-ulimit nproc=-1 --default-ulimit stack=-1'
INSECURE_REGISTRY='--insecure-registry https://registry.access.redhat.com'

DOCKER_CERT_PATH=/etc/docker

# If you want to add your own registry to be used for docker search and docker
# pull use the ADD_REGISTRY option to list a set of registries, each prepended
# with --add-registry flag. The first registry added will be the first registry
# searched.
#ADD_REGISTRY='--add-registry registry.access.redhat.com'

# If you want to block registries from being used, uncomment the BLOCK_REGISTRY
# option and give it a set of registries, each prepended with --block-registry
# flag. For example adding docker.io will stop users from downloading images
# from docker.io
# BLOCK_REGISTRY='--block-registry'

# If you have a registry secured with https but do not have proper certs
# distributed, you can tell docker to not look for full authorization by
# adding the registry to the INSECURE_REGISTRY line and uncommenting it.
# INSECURE_REGISTRY='--insecure-registry'

# On an SELinux system, if you remove the --selinux-enabled option, you
# also need to turn on the docker_transition_unconfined boolean.
# setsebool -P docker_transition_unconfined 1

# Location used for temporary files, such as those created by
# docker load and build operations. Default is /var/lib/docker/tmp
# Can be overriden by setting the following environment variable.
# DOCKER_TMPDIR=/var/tmp

# Controls the /etc/cron.daily/docker-logrotate cron job status.
# To disable, uncomment the line below.
# LOGROTATE=false

$ cat /etc/sysconfig/docker-storage
DOCKER_STORAGE_OPTIONS=--storage-driver devicemapper --storage-opt dm.fs=xfs --storage-opt dm.thinpooldev=/dev/mapper/docker--vg-docker--pool --storage-opt dm.use_deferred_removal=true --storage-opt dm.use_deferred_deletion=true

$ cat /etc/sysconfig/docker-network
# /etc/sysconfig/docker-network
DOCKER_NETWORK_OPTIONS=

$ cat /usr/lib/systemd/system/docker.service
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network.target firewalld.service

[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
ExecStart=/usr/bin/dockerd
ExecReload=/bin/kill -s HUP $MAINPID
# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
# Uncomment TasksMax if your systemd version supports it.
# Only systemd 226 and above support this version.
#TasksMax=infinity
TimeoutStartSec=0
# set delegate yes so that systemd does not reset the cgroups of docker containers
Delegate=yes
# kill only the docker process, not all processes in the cgroup
KillMode=process

[Install]
WantedBy=multi-user.target

$ cat /etc/docker/daemon.json
{
    "disable-legacy-registry": true,
    "max-concurrent-downloads": 10,
    "max-concurrent-uploads": 20,
    "log-level": "warn",
    "log-opts": {
        "max-size": "2m",
        "max-file": "5"
    },
    "storage-driver": "devicemapper",
    "storage-opts": [
        "dm.fs=xfs",
        "dm.thinpooldev=/dev/mapper/docker--vg-docker--pool",
        "dm.use_deferred_removal=true",
        "dm.use_deferred_deletion=true"
    ],
    "insecure-registries": ["https://registry.access.redhat.com"],
    "live-restore": true
}