docker 安装、升级、修改数据目录

1、查看系统要求

Docker 要求 CentOS 系统的内核版本高于 3.10 ,查看CentOS的内核版本。

uname -a

2、删除旧版本

yum remove docker  docker-common docker-selinux docker-engine

3、安装需要的软件包

yum-util 提供yum-config-manager功能，另外两个是devicemapper驱动依赖的

sudo yum install -y yum-utils device-mapper-persistent-data lvm2

4、设置Docker yum源

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

5、查看所有仓库中所有docker版本

可以查看所有仓库中所有docker版本,并选择特定的版本安装。

yum list docker-ce --showduplicates | sort -r

6、安装docker

sudo yum install docker-ce

由于repo中默认只开启stable仓库，故这里安装的是最新稳18.03.0.ce-1.el7.centos。

如果要安装特定版本：

sudo yum install docker-ce-18.06.1.ce

7、启动

设置为开机启动

systemctl enable docker

启动

systemctl start docker

查看启动状态

systemctl status docker

如果出现异常

$ systemctl start docker
A dependency job for docker.service failed. See 'journalctl -xe' for details.

查看报错信息

Mar 03 11:19:47 master1 systemd[1]: Starting containerd container runtime...
-- Subject: Unit containerd.service has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit containerd.service has begun starting up.
Mar 03 11:19:47 master1 systemd[104332]: Failed at step LIMITS spawning /sbin/modprobe: Operation not permitted
-- Subject: Process /sbin/modprobe could not be executed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- The process /sbin/modprobe could not be executed and failed.
--
-- The error number returned by this process is 1.
Mar 03 11:19:47 master1 systemd[104335]: Failed at step LIMITS spawning /usr/bin/containerd: Operation not permitted
-- Subject: Process /usr/bin/containerd could not be executed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- The process /usr/bin/containerd could not be executed and failed.

解决方案：

查看open files的值，修改/usr/lib/systemd/system/docker.service和/usr/lib/systemd/system/containerd.service（如下图），启动即可

$ ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 23056
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 654350
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 23056
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

$ vim /usr/lib/systemd/system/docker.service
...
# 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=654349 # 注意这里
LimitNPROC=23057
LimitCORE=infinity
# Comment TasksMax if your systemd version does not supports it.
...

$ vim /usr/lib/systemd/system/containerd.service
...
# 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=654349 # 注意这里
LimitNPROC=23057
LimitCORE=infinity

# Comment TasksMax if your systemd version does not support it.
...

查看版本

docker version

8、修改数据目录

查看docker当前信息

$ docker info
Client:
 Context:    default
 Debug Mode: false
 Plugins:
  app: Docker App (Docker Inc., v0.9.1-beta3)
  buildx: Docker Buildx (Docker Inc., v0.8.2-docker)
  scan: Docker Scan (Docker Inc., v0.17.0)

Server:
 Containers: 40
  Running: 15
  Paused: 0
  Stopped: 25
 Images: 91
 Server Version: 20.10.17
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 1
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 io.containerd.runtime.v1.linux runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 10c12954828e7c7c9b6e0ea9b0c02b01407d3ae1
 runc version: v1.1.2-0-ga916309f
 init version: de40ad0
 Security Options:
  seccomp
   Profile: default
 Kernel Version: 3.10.0-1160.71.1.el7.x86_64
 Operating System: CentOS Linux 7 (Core)
 OSType: linux
 Architecture: x86_64
 CPUs: 16
 Total Memory: 15.5GiB
 Name: master1
 ID: 3WQC:QCTB:I5D4:2ZWL:VBSH:6GWQ:4W2G:BTK2:XSEY:PDXG:BQAI:ZB6D
 Docker Root Dir: /data/docker   # 这里是数据目录的位置，我因为已经更改过，原位置为/var/lib/docker
 Debug Mode: false
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Registry Mirrors:
  https://x6u7jv2l.mirror.aliyuncs.com/
 Live Restore Enabled: false

9、停止docker服务

$ systemctl stop docker

10、修改docker服务启动文件

vi /usr/lib/systemd/system/docker.service
ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock --graph=/data/docker

11、复制原有数据，若无数据，可跳过此步骤

$ cp -rf /var/lib/docker/* /data/docker/

12、重新加载配置文件并启动

$  systemctl daemon-reload
$ systemctl start docker

最后执行步骤8，查看是否已启动