如何在 Ubuntu 中安装 Docker 并运行 Docker 容器
Docker是一种开源且流行的操作系统级虚拟化（俗称“容器化”）技术，主要运行在Linux和Windows上。 Docker 使用容器可以更轻松地创建、部署和运行应用程序。
通过容器，开发人员（和系统管理员）可以将应用程序与运行该应用程序所需的一切打包在一起——代码、运行时、库、环境变量和配置文件，然后将其全部交付作为一个包输出。是的，就是这么棒！
在本文中，我们将向您展示如何在 Ubuntu 发行版上安装 Docker CE（社区版）、创建和运行 Docker 容器。
在Ubuntu中安装Docker CE（社区版）
1.要安装Docker CE，首先需要删除旧版本的Docker，称为docker，<使用以下命令从系统中访问docker.io 或 docker-engine。
sudo apt-get remove docker docker-engine docker.io containerd runc
2. 接下来，您需要设置 Docker 存储库，以便使用以下命令从存储库安装和更新 Docker。
sudo apt-get update
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
3. 使用以下命令更新 apt 软件包索引并安装最新版本的 Docker CE。
sudo apt-get update
sudo apt-get install docker-ce docker-ce-cli containerd.io
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
aufs-tools cgroupfs-mount pigz
The following NEW packages will be installed:
aufs-tools cgroupfs-mount containerd.io docker-ce docker-ce-cli pigz
0 upgraded, 6 newly installed, 0 to remove and 167 not upgraded.
Need to get 50.7 MB of archives.
After this operation, 243 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 http://archive.ubuntu.com/ubuntu bionic/universe amd64 pigz amd64 2.4-1 [57.4 kB]
Get:2 https://download.docker.com/linux/ubuntu bionic/stable amd64 containerd.io amd64 1.2.4-1 [19.9 MB]
Get:3 http://archive.ubuntu.com/ubuntu bionic/universe amd64 aufs-tools amd64 1:4.9+20170918-1ubuntu1 [104 kB]
Get:4 http://archive.ubuntu.com/ubuntu bionic/universe amd64 cgroupfs-mount all 1.4 [6,320 B]
Get:5 https://download.docker.com/linux/ubuntu bionic/stable amd64 docker-ce-cli amd64 5:18.09.3~3-0~ubuntu-bionic [13.1 MB]
Get:6 https://download.docker.com/linux/ubuntu bionic/stable amd64 docker-ce amd64 5:18.09.3~3-0~ubuntu-bionic [17.4 MB]
Fetched 50.7 MB in 7s (7,779 kB/s)
...
4.成功安装Docker CE包后，该服务应该会自动启动并自动启用以在系统启动时启动，您可以使用以下命令检查其状态。
sudo systemctl status docker
● docker.service - Docker Application Container Engine
Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
Active: active (running) since Wed 2019-03-06 08:06:42 UTC; 2min 18s ago
Docs: https://docs.docker.com
Main PID: 5274 (dockerd)
Tasks: 8
CGroup: /system.slice/docker.service
└─5274 /usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock
Mar 06 08:06:41 tecmint dockerd[5274]: time="2019-03-06T08:06:41.562587408Z" level=warning msg="Your kernel does not support cgroup rt runtime"
Mar 06 08:06:41 tecmint dockerd[5274]: time="2019-03-06T08:06:41.562767803Z" level=warning msg="Your kernel does not support cgroup blkio weight"
Mar 06 08:06:41 tecmint dockerd[5274]: time="2019-03-06T08:06:41.562966844Z" level=warning msg="Your kernel does not support cgroup blkio weight_device"
Mar 06 08:06:41 tecmint dockerd[5274]: time="2019-03-06T08:06:41.565298457Z" level=info msg="Loading containers: start."
Mar 06 08:06:41 tecmint dockerd[5274]: time="2019-03-06T08:06:41.950942467Z" 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 prefer
Mar 06 08:06:42 tecmint dockerd[5274]: time="2019-03-06T08:06:42.036964493Z" level=info msg="Loading containers: done."
Mar 06 08:06:42 tecmint dockerd[5274]: time="2019-03-06T08:06:42.156279378Z" level=info msg="Docker daemon" commit=774a1f4 graphdriver(s)=overlay2 version=18.09.3
Mar 06 08:06:42 tecmint dockerd[5274]: time="2019-03-06T08:06:42.157145045Z" level=info msg="Daemon has completed initialization"
Mar 06 08:06:42 tecmint systemd[1]: Started Docker Application Container Engine.
Mar 06 08:06:42 tecmint dockerd[5274]: time="2019-03-06T08:06:42.224229999Z" level=info msg="API listen on /var/run/docker.sock"
5. 最后，通过运行 hello-world 镜像来验证 Docker CE 是否已正确安装。
sudo docker run hello-world
Hello from Docker!
This message shows that your installation appears to be working correctly.
To generate this message, Docker took the following steps:
1. The Docker client contacted the Docker daemon.
2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
(amd64)
3. The Docker daemon created a new container from that image which runs the
executable that produces the output you are currently reading.
4. The Docker daemon streamed that output to the Docker client, which sent it
to your terminal.
To try something more ambitious, you can run an Ubuntu container with:
$ docker run -it ubuntu bash
Share images, automate workflows, and more with a free Docker ID:
https://hub.docker.com/
For more examples and ideas, visit:
https://docs.docker.com/get-started/
学习 Ubuntu 中的基本 Docker 命令
6. 要获取有关 Docker 的信息，请运行以下命令。
sudo docker info
Kernel Version: 5.0.0-050000-generic
Operating System: Ubuntu 18.04.1 LTS
OSType: linux
Architecture: x86_64
CPUs: 1
Total Memory: 1.452GiB
Name: tecmint
ID: FWSB:IRIF:DYL7:PRB5:Y66E:37MY:ISPO:HZVY:6YJO:2IYL:TO6Y:GNB7
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
127.0.0.0/8
Live Restore Enabled: false
Product License: Community Engine
7. 要获取有关 Docker 版本的信息，请运行以下命令。
sudo docker version
Client:
Version: 18.09.3
API version: 1.39
Go version: go1.10.8
Git commit: 774a1f4
Built: Thu Feb 28 06:53:11 2019
OS/Arch: linux/amd64
Experimental: false
Server: Docker Engine - Community
Engine:
Version: 18.09.3
API version: 1.39 (minimum version 1.12)
Go version: go1.10.8
Git commit: 774a1f4
Built: Thu Feb 28 05:59:55 2019
OS/Arch: linux/amd64
Experimental: false
8. 要获取所有可用 Docker 命令的列表，请在终端上运行 docker。
docker
Usage: docker [OPTIONS] COMMAND
A self-sufficient runtime for containers
Options:
--config string Location of client config files (default "/home/tecmint/.docker")
-D, --debug Enable debug mode
-H, --host list Daemon socket(s) to connect to
-l, --log-level string Set the logging level ("debug"|"info"|"warn"|"error"|"fatal") (default "info")
--tls Use TLS; implied by --tlsverify
--tlscacert string Trust certs signed only by this CA (default "/home/tecmint/.docker/ca.pem")
--tlscert string Path to TLS certificate file (default "/home/tecmint/.docker/cert.pem")
--tlskey string Path to TLS key file (default "/home/tecmint/.docker/key.pem")
--tlsverify Use TLS and verify the remote
-v, --version Print version information and quit
Management Commands:
builder Manage builds
config Manage Docker configs
container Manage containers
engine Manage the docker engine
image Manage images
network Manage networks
node Manage Swarm nodes
plugin Manage plugins
secret Manage Docker secrets
service Manage services
stack Manage Docker stacks
swarm Manage Swarm
system Manage Docker
trust Manage trust on Docker images
volume Manage volumes
....
在 Ubuntu 中下载 Docker 镜像
9. 要运行 Docker 容器，首先，您需要从 Docker Hub 下载镜像 - 从其存储库提供免费镜像。
例如，要下载名为 CentOS 7 的 Docker 映像，请发出以下命令。
sudo docker search centos
NAME DESCRIPTION STARS OFFICIAL AUTOMATED
centos The official build of CentOS. 5227 [OK]
ansible/centos7-ansible Ansible on Centos7 120 [OK]
jdeathe/centos-ssh CentOS-6 6.10 x86_64 / CentOS-7 7.5.1804 x86… 107 [OK]
consol/centos-xfce-vnc Centos container with "headless" VNC session… 81 [OK]
imagine10255/centos6-lnmp-php56 centos6-lnmp-php56 50 [OK]
centos/mysql-57-centos7 MySQL 5.7 SQL database server 47
tutum/centos Simple CentOS docker image with SSH access 43
gluster/gluster-centos Official GlusterFS Image [ CentOS-7 + Glust… 40 [OK]
openshift/base-centos7 A Centos7 derived base image for Source-To-I… 39
centos/postgresql-96-centos7 PostgreSQL is an advanced Object-Relational … 37
centos/python-35-centos7 Platform for building and running Python 3.5… 33
kinogmt/centos-ssh CentOS with SSH 26 [OK]
openshift/jenkins-2-centos7 A Centos7 based Jenkins v2.x image for use w… 20
centos/php-56-centos7 Platform for building and running PHP 5.6 ap… 19
pivotaldata/centos-gpdb-dev CentOS image for GPDB development. Tag names… 10
openshift/wildfly-101-centos7 A Centos7 based WildFly v10.1 image for use … 6
openshift/jenkins-1-centos7 DEPRECATED: A Centos7 based Jenkins v1.x ima… 4
darksheer/centos Base Centos Image -- Updated hourly 3 [OK]
pivotaldata/centos Base centos, freshened up a little with a Do… 2
pivotaldata/centos-mingw Using the mingw toolchain to cross-compile t… 2
pivotaldata/centos-gcc-toolchain CentOS with a toolchain, but unaffiliated wi… 1
openshift/wildfly-81-centos7 A Centos7 based WildFly v8.1 image for use w… 1
blacklabelops/centos CentOS Base Image! Built and Updates Daily! 1 [OK]
smartentry/centos centos with smartentry 0 [OK]
jameseckersall/sonarr-centos Sonarr on CentOS 7 0 [OK]
10. 根据您的要求确定要运行的映像后，通过运行以下命令将其下载到本地（在本例中，将下载并使用 CentOS 映像） ）。
docker pull centos
Using default tag: latest
latest: Pulling from library/centos
a02a4930cb5d: Pull complete
Digest: sha256:184e5f35598e333bfa7de10d8fb1cebb5ee4df5bc0f970bf2b1e7c7345136426
Status: Downloaded newer image for centos:latest
11. 要列出主机上所有可用的 Docker 映像，请运行以下命令。
sudo docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
hello-world latest fce289e99eb9 2 months ago 1.84kB
centos latest 1e1148e4cc2c 3 months ago 202MB
12.如果您不再需要Docker映像，可以使用以下命令将其删除。
sudo docker rmi centos
Untagged: centos:latest
Untagged: centos@sha256:184e5f35598e333bfa7de10d8fb1cebb5ee4df5bc0f970bf2b1e7c7345136426
Deleted: sha256:1e1148e4cc2c148c6890a18e3b2d2dde41a6745ceb4e5fe94a923d811bf82ddb
Deleted: sha256:071d8bd765171080d01682844524be57ac9883e53079b6ac66707e192ea25956
在 Ubuntu 中运行 Docker 容器
13.为了创建并运行 Docker 容器，首先您需要在下载的 CentOS 映像中运行命令，因此基本命令是检查发行版本使用 cat 命令在容器内创建文件，如图所示。
docker run centos cat /etc/issue
14.要再次运行容器，首先需要通过运行以下命令获取容器 ID 或名称，该命令将显示正在运行和已停止的容器的列表：
sudo docker ps -l
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
0ddfa81c5779 centos "cat /etc/issue" About a minute ago Exited (0) About a minute ago elastic_shirley
15.获取容器ID或名称后，您可以使用以下命令启动容器：
sudo docker start 0ddfa81c5779
OR
sudo docker start elastic_shirley
这里，字符串 0ddfa81c5779 代表容器 ID，elastic_shirley 代表容器名称。
16. 要停止正在运行的容器，请通过指定容器 ID 或名称运行 docker stop 命令。
sudo docker stop 0ddfa81c5779
OR
sudo docker stop elastic_shirley
17. 一种更好的方法是使用 --name 为您创建的每个容器定义一个唯一的名称，这样您就不必记住容器 ID 选项如图所示。
docker run --name myname centos cat /etc/issue
18. 为了将 Linux 命令连接到容器中并运行，请发出以下命令。
docker run -it centos bash
[root@6213ec547863 /]# uname -a
Linux 6213ec547863 5.0.0-050000-generic #201903032031 SMP Mon Mar 4 01:33:18 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
[root@6213ec547863 /]# cat /etc/redhat-release
CentOS Linux release 7.6.1810 (Core)
19. 要从正在运行的容器会话退出并返回到主机，您必须输入 exit 命令，如下所示。
exit
这就是基本的容器操作。如果您对本文有任何疑问或意见，请使用下面的反馈表联系我们。