docker基础用法

OCI

Open Container-initiative

由Linux基金会主导于2015年6月创立
旨在围绕容器格式和运行时制定一个开放的工业化标准
contains two specifications
- the Runtime Specification（runtime-spec）
- the Image Specification（image-spec）

OCF

Open Container Format

runC is a CLI tool for spawning and running containers according to the OCI specification

Containers are started as a child process of runC and can be embedded into various other systems without having to run a daemon
runC is built on libcontainer, the same container technology powering millions of Docker Engine installations

docker提供了一个专门容纳容器镜像的站点：https://hub.docker.com

docker架构

docker镜像与镜像仓库

镜像是静态的，而容器是动态的，容器有其生命周期，镜像与容器的关系类似于程序与进程的关系。镜像类似于文件系统中的程序文件，而容器则类似于将一个程序运行起来的状态，也即进程。所以容器是可以删除的，容器被删除后其镜像是不会被删除的。

docker对象

When you use docker, you are creating and using images, containers, networks, volumes, pluginns, and other objects.

IMAGES
- An image is a read-only template with instructions for creating a docker container.
- Often, an image is based on another image, with some additional customization.
- You might create your own images or you might only use those created by others and published in a registry.
CONTAINERS
- A conntainer is a runnable instance of an image.
- You can create, run, stop, move, or delete a container using the docker API or CLI.
- You can connect a container to one or more networks, attach storage to it, or even create a new image based on its current state.

安装及使用docker

docker安装

[root@localhost ~]# cd /etc/yum.repos.d/
[root@localhost yum.repos.d]# curl -o docker-ce.repo https://mirrors.tuna.tsinghua.edu.cn/docker-ce/linux/centos/docker-ce.repo
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0     0    0     0    0     0      0      0 --:--:--  0:00:01 --:--:--   100  1919  100  1919    0     0    767      0  0:00:02  0:00:02 --:--:--   767
[root@localhost yum.repos.d]# sed -i 's@https://download.docker.com@https://mirrors.tuna.tsinghua.edu.cn/docker-ce@g' docker-ce.repo
[root@localhost yum.repos.d]# yum clean all
Updating Subscription Management repositories.
Unable to read consumer identity
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Repository AppStream is listed more than once in the configuration
46 文件已删除
[root@localhost yum.repos.d]# yum -y install docker-ce
完毕！
[root@localhost yum.repos.d]# systemctl start docker
[root@localhost yum.repos.d]#

docker加速

docker-ce的配置文件是/etc/docker/daemon.json，此文件默认不存在，需要我们手动创建并进行配置，而docker的加速就是通过配置此文件来实现的。

docker的加速有多种方式：

docker cn
中国科技大学加速器
阿里云加速器（需要通过阿里云开发者平台注册帐号，免费使用个人私有的加速器）

docker常用操作

命令	功能
docker search	从Docker Hub查找镜像
docker pull	从镜像仓库中拉取或者更新指定镜像
docker images	列出本地镜像
docker create	创建一个新的容器
docker start	启动一个或多个已经被停止的容器
docker run	创建一个新的容器并运行一个命令
docker attach	连接到正在运行中的容器
docker ps	列出容器
docker logs	获取容器的日志
docker restart	重启容器
docker stop	停止一个运行中的容器
docker kill	杀掉一个运行中的容器
docker rm	删除一个容器或多个
docker exec	在运行的容器中执行命令
docker info	显示 Docker 系统信息，包括镜像和容器数
docker inspect	获取容器/镜像的元数据

docker search

[root@localhost ~]# docker search centos
NAME                               DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
centos                             The official build of CentOS.                   6423      [OK]       
ansible/centos7-ansible            Ansible on Centos7                              132                  [OK]
consol/centos-xfce-vnc             Centos container with "headless" VNC session…   125                  [OK]
jdeathe/centos-ssh                 OpenSSH / Supervisor / EPEL/IUS/SCL Repos - …   117                  [OK]
centos/systemd                     systemd enabled base container.                 96                   [OK]
imagine10255/centos6-lnmp-php56    centos6-lnmp-php56                              58                   [OK]
tutum/centos                       Simple CentOS docker image with SSH access      46                   
kinogmt/centos-ssh                 CentOS with SSH                                 29                   [OK]
pivotaldata/centos-gpdb-dev        CentOS image for GPDB development. Tag names…   13                   
guyton/centos6                     From official centos6 container with full up…   10                   [OK]
centos/tools                       Docker image that has systems administration…   7                    [OK]
drecom/centos-ruby                 centos ruby                                     6                    [OK]
pivotaldata/centos                 Base centos, freshened up a little with a Do…   5                    
mamohr/centos-java                 Oracle Java 8 Docker image based on Centos 7    3                    [OK]
darksheer/centos                   Base Centos Image -- Updated hourly             3                    [OK]
pivotaldata/centos-mingw           Using the mingw toolchain to cross-compile t…   3                    
pivotaldata/centos-gcc-toolchain   CentOS with a toolchain, but unaffiliated wi…   3                    
amd64/centos                       The official build of CentOS.                   2                    
miko2u/centos6                     CentOS6 日本語環境                                   2                    [OK]
mcnaughton/centos-base             centos base image                               1                    [OK]
indigo/centos-maven                Vanilla CentOS 7 with Oracle Java Developmen…   1                    [OK]
blacklabelops/centos               CentOS Base Image! Built and Updates Daily!     1                    [OK]
pivotaldata/centos6.8-dev          CentosOS 6.8 image for GPDB development         0                    
pivotaldata/centos7-dev            CentosOS 7 image for GPDB development           0                    
smartentry/centos                  centos with smartentry                          0                    [OK]

docker pull

[root@localhost ~]# docker pull centos
Using default tag: latest
latest: Pulling from library/centos
7a0437f04f83: Pull complete 
Digest: sha256:5528e8b1b1719d34604c87e11dcd1c0a20bedf46e83b5632cdeac91b8c04efc1
Status: Downloaded newer image for centos:latest
docker.io/library/centos:latest
[root@localhost ~]#

docker images

[root@localhost ~]# docker images
REPOSITORY   TAG       IMAGE ID       CREATED        SIZE
centos       latest    300e315adb2f   2 months ago   209MB
[root@localhost ~]#

docker create

[root@localhost ~]# docker create centos:latest
519a59f646dcf1569ed6676020e64ab0d00d8f57cd743c1211ba547d7a95a8b6
[root@localhost ~]#

docker start

[root@localhost ~]# docker start 519a59f646dc
519a59f646dc

docker ps

[root@localhost ~]# docker ps -a
CONTAINER ID   IMAGE           COMMAND       CREATED          STATUS                     PORTS     NAMES
519a59f646dc   centos:latest   "/bin/bash"   20 minutes ago   Exited (0) 7 seconds ago             intelligent_albattani
[root@localhost ~]#

docker rm

[root@localhost ~]# docker rm -f 519a59f646dc
519a59f646dc
[root@localhost ~]# docker ps -a
CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES
[root@localhost ~]#

docker run

[root@localhost ~]# docker run httpd:latest
Unable to find image 'httpd:latest' locally
latest: Pulling from library/httpd
45b42c59be33: Pull complete 
83ac8490fcc3: Pull complete 
bdb2d204d86d: Pull complete 
243acf75a504: Pull complete 
8fc1ad93a9b1: Pull complete 
Digest: sha256:3c252c919ef2445a6a41dde913a56202754821af87c049c4312bf81bdbc6df4b
[root@localhost ~]# docker ps -a
CONTAINER ID   IMAGE          COMMAND              CREATED          STATUS          PORTS     NAMES
59d3a4fcabcc   httpd:latest   "httpd-foreground"   34 seconds ago   Up 33 seconds   80/tcp    wonderful_carson
fc4f74de4178   httpd:latest   "httpd-foreground"   26 minutes ago   Up 26 minutes   80/tcp    silly_einstein

docker logs

[root@localhost ~]# docker logs 59d3a4fcabcc
AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using 172.17.0.3. Set the 'ServerName' directive globally to suppress this message
AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using 172.17.0.3. Set the 'ServerName' directive globally to suppress this message
[Fri Feb 26 12:51:06.886049 2021] [mpm_event:notice] [pid 1:tid 140494586573952] AH00489: Apache/2.4.46 (Unix) configured -- resuming normal operations
[Fri Feb 26 12:51:06.886206 2021] [core:notice] [pid 1:tid 140494586573952] AH00094: Command line: 'httpd -D FOREGROUND'
[Fri Feb 26 12:52:19.990760 2021] [mpm_event:notice] [pid 1:tid 140494586573952] AH00491: caught SIGTERM, shutting down

docker inspect

[root@localhost ~]# docker inspect 59d3a4fcabcc
[
    {
        "Id": "59d3a4fcabcc23df155628fcfdf383bcef3cf3515e2dd5fe14acdf8500d02493",
        "Created": "2021-02-26T12:51:06.248185821Z",
        "Path": "httpd-foreground",
        "Args": [],
        "State": {
            "Status": "exited",
            "Running": false,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 0,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2021-02-26T12:51:06.864845592Z",
            "FinishedAt": "2021-02-26T12:52:20.00336636Z"
        },

docker event state

posted @ 2021-02-26 12:07 cbcbage 阅读(113) 评论(0) 收藏举报

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