[root@dev-istio-master-001 ~]# cat /etc/systemd/system/docker.service.d/docker.conf
[Service]
ExecStart=
ExecStart=/usr/bin/dockerd -D -H unix:///var/run/docker.sock -g /data/docker -D --insecure-registry docker.v2.aispeech.com --registry-mirror=https://pqbap4ya.mirror.aliyuncs.com
其中：
ExecStart清除docker.service文件中设置的ExecStart；ExecStart是实际的dockerd启动参数；-D：打开调试模式。大量无价值的docker daemon进程的调试日志反而不方便检查docker引擎问题，关闭调试模式；-H：连接的daemon的Socket，使用unix://而非配置不当可能有安全风险的tcp://；-g：老版本Docker中指定容器的存储目录，新版本Docker已经替换为--data-root参数；--insecure-registry：不安全的Docker镜像仓库，用于没有TLS加密的镜像仓库，可以加快镜像下载速度；--registry-mirror：安全的Docker镜像仓库，可以加快镜像下载速度。这里更换为公司阿里云帐号的镜像加速器https://woom60mt.mirror.aliyuncs.com。--group：Unix Socket文件/var/run/docker.sock的用户组，指定为docker，方便授予其他用户使用docker命令；--max-concurrent-downloads：docker pull的并发数，默认为3，改为10加快镜像下载速度；--max-concurrent-uploads：docker push的并发数，默认为5，改为10加快镜像上传速度；--live-restore：停止docker daemon进程时不关闭容器，方便在线升级docker；--log-opts：根据需要配置，这里尚未添加。[root@dev-istio-master-001 ~]# cat >/etc/systemd/system/docker.service.d/docker.conf <<EOF
[Service]
ExecStart=
ExecStart=/usr/bin/dockerd -H unix:///var/run/docker.sock --data-root /data/docker --insecure-registry docker.v2.aispeech.com --registry-mirror=https://woom60mt.mirror.aliyuncs.com --group=docker --max-concurrent-downloads=10 --max-concurrent-uploads=10 --live-restore
EOF
[root@dev-istio-master-001 ~]# systemctl daemon-reload
[root@dev-istio-master-001 ~]# systemctl restart docker.service
docker.service的状态：
[root@dev-istio-master-001 ~]# systemctl status -l docker.service
● docker.service - Docker Application Container Engine
Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled; vendor preset: disabled)
Drop-In: /etc/systemd/system/docker.service.d
└─docker.conf
Active: active (running) since Sat 2019-04-20 16:59:59 CST; 6min ago
Docs: https://docs.docker.com
Main PID: 13946 (dockerd)
Tasks: 13
Memory: 30.8M
CGroup: /system.slice/docker.service
└─13946 /usr/bin/dockerd -H unix:///var/run/docker.sock --data-root /data/docker --insecure-registry docker.v2.aispeech.com --registry-mirror=https://woom60mt.mirror.aliyuncs.com --group=docker --max-concurrent-downloads=10 --max-concurrent-uploads=10 --live-restore
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.869468329+08:00" level=info msg="pickfirstBalancer: HandleSubConnStateChange: 0xc420172cb0, READY" module=grpc
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.905159955+08:00" level=info msg="[graphdriver] using prior storage driver: overlay2"
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.916786494+08:00" level=info msg="Graph migration to content-addressability took 0.00 seconds"
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.917658736+08:00" level=info msg="Loading containers: start."
Apr 20 16:59:59 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:59.147425282+08:00" level=info msg="Default bridge (docker0) is assigned with an IP address 172.17.0.0/16. Daemon option --bip can be used to set a preferred IP address"
Apr 20 16:59:59 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:59.217883047+08:00" level=info msg="Loading containers: done."
Apr 20 16:59:59 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:59.243030636+08:00" level=info msg="Docker daemon" commit=4d60db4 graphdriver(s)=overlay2 version=18.09.0
Apr 20 16:59:59 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:59.243133740+08:00" level=info msg="Daemon has completed initialization"
Apr 20 16:59:59 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:59.250480541+08:00" level=info msg="API listen on /var/run/docker.sock"
Apr 20 16:59:59 dev-istio-master-001 systemd[1]: Started Docker Application Container Engine.
docker.service的日志：
[root@dev-istio-master-001 ~]# journalctl -ru docker.service
-- Logs begin at Sat 2019-04-20 12:25:48 CST, end at Sat 2019-04-20 17:01:01 CST. --
Apr 20 16:59:59 dev-istio-master-001 systemd[1]: Started Docker Application Container Engine.
Apr 20 16:59:59 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:59.250480541+08:00" level=info msg="API listen on /var
Apr 20 16:59:59 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:59.243133740+08:00" level=info msg="Daemon has complet
Apr 20 16:59:59 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:59.243030636+08:00" level=info msg="Docker daemon" com
Apr 20 16:59:59 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:59.217883047+08:00" level=info msg="Loading containers
Apr 20 16:59:59 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:59.147425282+08:00" level=info msg="Default bridge (do
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.917658736+08:00" level=info msg="Loading containers
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.916786494+08:00" level=info msg="Graph migration to
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.905159955+08:00" level=info msg="[graphdriver] usin
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.869468329+08:00" level=info msg="pickfirstBalancer:
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.869467105+08:00" level=info msg="pickfirstBalancer:
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.869350266+08:00" level=info msg="pickfirstBalancer:
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.869289944+08:00" level=info msg="ClientConn switchi
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.869288783+08:00" level=info msg="pickfirstBalancer:
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.869263737+08:00" level=info msg="ccResolverWrapper:
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.869231551+08:00" level=info msg="ClientConn switchi
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.869193447+08:00" level=info msg="ccResolverWrapper:
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.869120409+08:00" level=info msg="scheme \"unix\" no
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.869110056+08:00" level=info msg="parsed scheme: \"u
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.868999557+08:00" level=info msg="scheme \"unix\" no
Apr 20 16:59:58 dev-istio-master-001 dockerd[13946]: time="2019-04-20T16:59:58.868903397+08:00" level=info msg="parsed scheme: \"u
Apr 20 16:59:58 dev-istio-master-001 systemd[1]: Starting Docker Application Container Engine...
-r选项倒序显示日志；docker daemon的信息：
[root@dev-istio-master-001 ~]# docker info
Containers: 0
Running: 0
Paused: 0
Stopped: 0
Images: 0
Server Version: 18.09.0
Storage Driver: overlay2
Backing Filesystem: xfs
Supports d_type: true
Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
Volume: local
Network: bridge host macvlan null overlay
Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: c4446665cb9c30056f4998ed953e6d4ff22c7c39
runc version: 4fc53a81fb7c994640722ac585fa9ca548971871
init version: fec3683
Security Options:
seccomp
Profile: default
Kernel Version: 3.10.0-957.10.1.el7.x86_64
Operating System: CentOS Linux 7 (Core)
OSType: linux
Architecture: x86_64
CPUs: 4
Total Memory: 7.638GiB
Name: dev-istio-master-001
ID: TARV:EFOR:J5BH:3KVI:2ET5:4LUT:WJ4G:BQDX:7WSC:DXKP:OWK6:7ORC
Docker Root Dir: /data/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
docker.v2.aispeech.com
127.0.0.0/8
Registry Mirrors:
https://woom60mt.mirror.aliyuncs.com/
Live Restore Enabled: true
Product License: Community Engine