一、Docker架构

Docker架构.png

Docker服务中各个角色

• Client：客户端，操作Docker服务器的客户端（命令行 或 界面）
• DOCKER_HOST：Docker主机，安装Docker服务的主机
• Docker_Daemon：后台进程，运行在Docker服务器的后台进程
• Containers：容器，在Docker服务器中容器（一个容器一般是一个应用实例，容器间相互隔离）
• Images：镜像、映射、程序包，Image是只读模板，其中包含创建Docker容器的说明。容器是由Image运行而来，Image固定不变
• Registries：仓库，存储Docker Image的地方。官方远程仓库

二、Docker隔离原理

namespace 6项隔离（资源隔离）

image.png

cgroups资源限制（资源限制）

• 资源限制：限制任务使用的资源总额，并在超过这个 配额 时发出提示
• 优先级分配：分配 CPU 时间片数量及磁盘IO贷款大小、控制任务运行的优先级
• 资源统计：统计系统资源使用量，如 CPU 使用时长、内存用量

• 任务控制：对任务执行挂起、恢复等操作

  
  
  image.png

三、Docker安装

1、移除旧版本

sudo yum remove docker \
                  docker-client \
                  docker-client-latest \
                  docker-common \
                  docker-latest \
                  docker-latest-logrotate \
                  docker-logrotate \
                  docker-engine

2、设置 docker yum源

sudo yum install -y yum-utils

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

3、安装最新docker engine

sudo yum install docker-ce docker-ce-cli containerd.io

4、查看docker版本

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

5、安装指定版本docker

sudo yum install docker-ce-<VERSION_STRING> docker-ce-cli-<VERSION_STRING> containerd.io

eg:
sudo yum install docker-ce-3:19.03.9-3.el7.x86_64 docker-ce-cli-3:19.03.9-3.el7.x86_64 containerd.io

6、启动docker

sudo systemctl start docker

7、设置开机启动

sudo systemctl enable docker

8、设置镜像加速（阿里云）

• 登录阿里云，搜索 镜像服务

sudo mkdir -p /etc/docker
sudo tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://knk5i905.mirror.aliyuncs.com"]
}
EOF
sudo systemctl daemon-reload
sudo systemctl restart docker

四、docker命令

• 删除全部容器

docker rm -f $(docker ps -aq)

五、Docker 实操

Docker Hub

image.png

镜像是什么？

• 镜像就是基础环境 + 软件
• Nginx镜像：linux系统 + Nginx软件
• alpine：超级经典版linux，特别小，推荐下载带有alpine的镜像

5-1、镜像相关操作命令

1、查看当前镜像

docker images

docker images.png

2、搜索镜像，或从 DockerHub搜索

docker search nginx

image.png

3、拉取镜像

docker pull nginx

image.png

• 再次查询当前镜像，Nginx 镜像已经拉取下来
  image.png

4、查看镜像历史-history

image.png

5.1、删除镜像-rmi

image.png

5.2、删除全部镜像

docker rmi -f $(docker images -aq) #删除全部镜像

6、重新命名镜像-tag

docker tag 原镜像:标签 新镜像名:标签 #重命名
docker tag nginx:latest nginx:v1

image.png

5-2、容器相关操作命令

1.1、创建前台容器

docker run --name mynginx -p 80:80 nginx

• 前台启动容器会造成界面“卡死”，退出界面时，容器也会销毁，所以不推荐使用前台方式创建容器
• 创建容器时一定要暴露端口，否则无法访问

• 暴露端口时，: 前的端口时宿主机的端口，：后的端口时容器的端口

  
  
  image.png

1.2、创建后台容器

docker create --name mynginx -p 80:80 nginx:latest

docker run -d --name mynginx -p 80:80 nginx:latest

• 主要

docker run -d = docker create + docker start

image.png

• 此时容器已经创建，但是并没有启动，所以需要手动启动

docker start 19f9872bd2f862bfeb7c202913616d2b081f47cff37ff375a2b4922d116b5184

• 访问容器
  image.png

2、查看当前容器

docker ps  # 查看存活的容器
docker ps -a  #查看所有容器

image.png

3.1、停止容器-优雅停机

docker stop 容器名称/容器ID

3.2、停止容器-强制停机

docker kill 容器名称/容器ID

4.1、进入容器

• docker attach 绑定的是控制台，可能导致容器停止。不推荐使用

docker attach 容器名称/容器ID

4.2、进入容器

• u：指定用户
• privileged：root用户权限

docker exec -it -u 0:0 --privileged 8f /bin/bash

5-3、其他操作

1、查看指定容器信息

docker container inspect 容器名称/容器ID

[
    {
        "Id": "8f748061c8633a4cab4b88e93e784386d6340f154842946489708d6e690cae3a",
        "Created": "2021-10-11T05:42:14.366993454Z",
        "Path": "/docker-entrypoint.sh",
        "Args": [
            "nginx",
            "-g",
            "daemon off;"
        ],
        "State": {
            "Status": "running",
            "Running": true,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 14034,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2021-10-11T05:46:59.65645698Z",
            "FinishedAt": "2021-10-11T05:45:30.906537809Z"
        },
        "Image": "sha256:f8f4ffc8092c956ddd6a3a64814f36882798065799b8aedeebedf2855af3395b",
        "ResolvConfPath": "/var/lib/docker/containers/8f748061c8633a4cab4b88e93e784386d6340f154842946489708d6e690cae3a/resolv.conf",
        "HostnamePath": "/var/lib/docker/containers/8f748061c8633a4cab4b88e93e784386d6340f154842946489708d6e690cae3a/hostname",
        "HostsPath": "/var/lib/docker/containers/8f748061c8633a4cab4b88e93e784386d6340f154842946489708d6e690cae3a/hosts",
        "LogPath": "/var/lib/docker/containers/8f748061c8633a4cab4b88e93e784386d6340f154842946489708d6e690cae3a/8f748061c8633a4cab4b88e93e784386d6340f154842946489708d6e690cae3a-json.log",
        "Name": "/mynginx",
        "RestartCount": 0,
        "Driver": "overlay2",
        "Platform": "linux",
        "MountLabel": "",
        "ProcessLabel": "",
        "AppArmorProfile": "",
        "ExecIDs": null,
        "HostConfig": {
            "Binds": null,
            "ContainerIDFile": "",
            "LogConfig": {
                "Type": "json-file",
                "Config": {}
            },
            "NetworkMode": "default",
            "PortBindings": {
                "80/tcp": [
                    {
                        "HostIp": "",
                        "HostPort": "80"
                    }
                ]
            },
            "RestartPolicy": {
                "Name": "no",
                "MaximumRetryCount": 0
            },
            "AutoRemove": false,
            "VolumeDriver": "",
            "VolumesFrom": null,
            "CapAdd": null,
            "CapDrop": null,
            "Capabilities": null,
            "Dns": [],
            "DnsOptions": [],
            "DnsSearch": [],
            "ExtraHosts": null,
            "GroupAdd": null,
            "IpcMode": "private",
            "Cgroup": "",
            "Links": null,
            "OomScoreAdj": 0,
            "PidMode": "",
            "Privileged": false,
            "PublishAllPorts": false,
            "ReadonlyRootfs": false,
            "SecurityOpt": null,
            "UTSMode": "",
            "UsernsMode": "",
            "ShmSize": 67108864,
            "Runtime": "runc",
            "ConsoleSize": [
                0,
                0
            ],
            "Isolation": "",
            "CpuShares": 0,
            "Memory": 0,
            "NanoCpus": 0,
            "CgroupParent": "",
            "BlkioWeight": 0,
            "BlkioWeightDevice": [],
            "BlkioDeviceReadBps": null,
            "BlkioDeviceWriteBps": null,
            "BlkioDeviceReadIOps": null,
            "BlkioDeviceWriteIOps": null,
            "CpuPeriod": 0,
            "CpuQuota": 0,
            "CpuRealtimePeriod": 0,
            "CpuRealtimeRuntime": 0,
            "CpusetCpus": "",
            "CpusetMems": "",
            "Devices": [],
            "DeviceCgroupRules": null,
            "DeviceRequests": null,
            "KernelMemory": 0,
            "KernelMemoryTCP": 0,
            "MemoryReservation": 0,
            "MemorySwap": 0,
            "MemorySwappiness": null,
            "OomKillDisable": false,
            "PidsLimit": null,
            "Ulimits": null,
            "CpuCount": 0,
            "CpuPercent": 0,
            "IOMaximumIOps": 0,
            "IOMaximumBandwidth": 0,
            "MaskedPaths": [
                "/proc/asound",
                "/proc/acpi",
                "/proc/kcore",
                "/proc/keys",
                "/proc/latency_stats",
                "/proc/timer_list",
                "/proc/timer_stats",
                "/proc/sched_debug",
                "/proc/scsi",
                "/sys/firmware"
            ],
            "ReadonlyPaths": [
                "/proc/bus",
                "/proc/fs",
                "/proc/irq",
                "/proc/sys",
                "/proc/sysrq-trigger"
            ]
        },
        "GraphDriver": {
            "Data": {
                "LowerDir": "/var/lib/docker/overlay2/53b355159525f0416f9ecbd26be9805a1ec3669e1cb8d6a808a1b29e7f31aafa-init/diff:/var/lib/docker/overlay2/a42a845eb3a8c4ebd267fdc2fbabd8715f7ccb79421a749209ee941800d3b476/diff:/var/lib/docker/overlay2/2639f8f3420a4be991cbeec99a7469878a7e2b4800e7e0c63c07c640b46cbe96/diff:/var/lib/docker/overlay2/987ba75856862bd5fd1475ba04d4392ee1f1f2de2db4aa5f1bbf2b846ea4522c/diff:/var/lib/docker/overlay2/80814a5662b4893ef088766cb184621638635ec3be0b443cc77ec01ad5d9957d/diff:/var/lib/docker/overlay2/d8bf757fa7d333a578c0df3f857593246b4d1207388deab1680ea21b5daf3a69/diff:/var/lib/docker/overlay2/d3db0eb5df44cae935c00e0e8e2b56e3bdd45aac6e0274474c45fda7775a8fe5/diff",
                "MergedDir": "/var/lib/docker/overlay2/53b355159525f0416f9ecbd26be9805a1ec3669e1cb8d6a808a1b29e7f31aafa/merged",
                "UpperDir": "/var/lib/docker/overlay2/53b355159525f0416f9ecbd26be9805a1ec3669e1cb8d6a808a1b29e7f31aafa/diff",
                "WorkDir": "/var/lib/docker/overlay2/53b355159525f0416f9ecbd26be9805a1ec3669e1cb8d6a808a1b29e7f31aafa/work"
            },
            "Name": "overlay2"
        },
        "Mounts": [],
        "Config": {
            "Hostname": "8f748061c863",
            "Domainname": "",
            "User": "",
            "AttachStdin": false,
            "AttachStdout": false,
            "AttachStderr": false,
            "ExposedPorts": {
                "80/tcp": {}
            },
            "Tty": false,
            "OpenStdin": false,
            "StdinOnce": false,
            "Env": [
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
                "NGINX_VERSION=1.21.3",
                "NJS_VERSION=0.6.2",
                "PKG_RELEASE=1~buster"
            ],
            "Cmd": [
                "nginx",
                "-g",
                "daemon off;"
            ],
            "Image": "nginx:latest",
            "Volumes": null,
            "WorkingDir": "",
            "Entrypoint": [
                "/docker-entrypoint.sh"
            ],
            "OnBuild": null,
            "Labels": {
                "maintainer": "NGINX Docker Maintainers <docker-maint@nginx.com>"
            },
            "StopSignal": "SIGQUIT"
        },
        "NetworkSettings": {
            "Bridge": "",
            "SandboxID": "f595a73dbfadf0b60039a281e44e80b02a7036f83b658d7c92bc942ba0628d5a",
            "HairpinMode": false,
            "LinkLocalIPv6Address": "",
            "LinkLocalIPv6PrefixLen": 0,
            "Ports": {
                "80/tcp": [
                    {
                        "HostIp": "0.0.0.0",
                        "HostPort": "80"
                    }
                ]
            },
            "SandboxKey": "/var/run/docker/netns/f595a73dbfad",
            "SecondaryIPAddresses": null,
            "SecondaryIPv6Addresses": null,
            "EndpointID": "703c83a6d08f6cd2b931ae6d6e2c4e060d77d56bc36bd96db51a7670c8bce3d7",
            "Gateway": "172.17.0.1",
            "GlobalIPv6Address": "",
            "GlobalIPv6PrefixLen": 0,
            "IPAddress": "172.17.0.2",
            "IPPrefixLen": 16,
            "IPv6Gateway": "",
            "MacAddress": "02:42:ac:11:00:02",
            "Networks": {
                "bridge": {
                    "IPAMConfig": null,
                    "Links": null,
                    "Aliases": null,
                    "NetworkID": "438e2a0e3e17fbe139fbe50c1b9641aaa6bc5aad85029898aa938e3d349cf8c4",
                    "EndpointID": "703c83a6d08f6cd2b931ae6d6e2c4e060d77d56bc36bd96db51a7670c8bce3d7",
                    "Gateway": "172.17.0.1",
                    "IPAddress": "172.17.0.2",
                    "IPPrefixLen": 16,
                    "IPv6Gateway": "",
                    "GlobalIPv6Address": "",
                    "GlobalIPv6PrefixLen": 0,
                    "MacAddress": "02:42:ac:11:00:02",
                    "DriverOpts": null
                }
            }
        }
    }
]

2、查看指定镜像信息

docker inspect 镜像名称 / 镜像ID

[
    {
        "Id": "sha256:f8f4ffc8092c956ddd6a3a64814f36882798065799b8aedeebedf2855af3395b",
        "RepoTags": [
            "nginx:latest",
            "nginx:v1"
        ],
        "RepoDigests": [
            "nginx@sha256:06e4235e95299b1d6d595c5ef4c41a9b12641f6683136c18394b858967cd1506"
        ],
        "Parent": "",
        "Comment": "",
        "Created": "2021-09-28T08:26:07.57996119Z",
        "Container": "449a8a48a9f56c3616a0b58ce3fea705fa34293def3c95bc32b50b9bc52f3ff7",
        "ContainerConfig": {
            "Hostname": "449a8a48a9f5",
            "Domainname": "",
            "User": "",
            "AttachStdin": false,
            "AttachStdout": false,
            "AttachStderr": false,
            "ExposedPorts": {
                "80/tcp": {}
            },
            "Tty": false,
            "OpenStdin": false,
            "StdinOnce": false,
            "Env": [
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
                "NGINX_VERSION=1.21.3",
                "NJS_VERSION=0.6.2",
                "PKG_RELEASE=1~buster"
            ],
            "Cmd": [
                "/bin/sh",
                "-c",
                "#(nop) ",
                "CMD [\"nginx\" \"-g\" \"daemon off;\"]"
            ],
            "Image": "sha256:dce61176f89cfe1ba4ca3eb3c39097b455d90108498072a77ebaac245c5732cc",
            "Volumes": null,
            "WorkingDir": "",
            "Entrypoint": [
                "/docker-entrypoint.sh"
            ],
            "OnBuild": null,
            "Labels": {
                "maintainer": "NGINX Docker Maintainers <docker-maint@nginx.com>"
            },
            "StopSignal": "SIGQUIT"
        },
        "DockerVersion": "20.10.7",
        "Author": "",
        "Config": {
            "Hostname": "",
            "Domainname": "",
            "User": "",
            "AttachStdin": false,
            "AttachStdout": false,
            "AttachStderr": false,
            "ExposedPorts": {
                "80/tcp": {}
            },
            "Tty": false,
            "OpenStdin": false,
            "StdinOnce": false,
            "Env": [
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
                "NGINX_VERSION=1.21.3",
                "NJS_VERSION=0.6.2",
                "PKG_RELEASE=1~buster"
            ],
            "Cmd": [
                "nginx",
                "-g",
                "daemon off;"
            ],
            "Image": "sha256:dce61176f89cfe1ba4ca3eb3c39097b455d90108498072a77ebaac245c5732cc",
            "Volumes": null,
            "WorkingDir": "",
            "Entrypoint": [
                "/docker-entrypoint.sh"
            ],
            "OnBuild": null,
            "Labels": {
                "maintainer": "NGINX Docker Maintainers <docker-maint@nginx.com>"
            },
            "StopSignal": "SIGQUIT"
        },
        "Architecture": "amd64",
        "Os": "linux",
        "Size": 133283279,
        "VirtualSize": 133283279,
        "GraphDriver": {
            "Data": {
                "LowerDir": "/var/lib/docker/overlay2/2639f8f3420a4be991cbeec99a7469878a7e2b4800e7e0c63c07c640b46cbe96/diff:/var/lib/docker/overlay2/987ba75856862bd5fd1475ba04d4392ee1f1f2de2db4aa5f1bbf2b846ea4522c/diff:/var/lib/docker/overlay2/80814a5662b4893ef088766cb184621638635ec3be0b443cc77ec01ad5d9957d/diff:/var/lib/docker/overlay2/d8bf757fa7d333a578c0df3f857593246b4d1207388deab1680ea21b5daf3a69/diff:/var/lib/docker/overlay2/d3db0eb5df44cae935c00e0e8e2b56e3bdd45aac6e0274474c45fda7775a8fe5/diff",
                "MergedDir": "/var/lib/docker/overlay2/a42a845eb3a8c4ebd267fdc2fbabd8715f7ccb79421a749209ee941800d3b476/merged",
                "UpperDir": "/var/lib/docker/overlay2/a42a845eb3a8c4ebd267fdc2fbabd8715f7ccb79421a749209ee941800d3b476/diff",
                "WorkDir": "/var/lib/docker/overlay2/a42a845eb3a8c4ebd267fdc2fbabd8715f7ccb79421a749209ee941800d3b476/work"
            },
            "Name": "overlay2"
        },
        "RootFS": {
            "Type": "layers",
            "Layers": [
                "sha256:476baebdfbf7a68c50e979971fcd47d799d1b194bcf1f03c1c979e9262bcd364",
                "sha256:5259501115588b1be0b1bb6eee115422d2939f402137979603cea9d9f1e649ec",
                "sha256:0772cb25d5cae1b4e6e47ff15af95fa1d2640c3b7c74cb4c008d61e2c8c28559",
                "sha256:6e109f6c2f99fdfa436dd66299d2ed87a18fee00b5f22fbd761dbacac27b76a6",
                "sha256:88891187bdd7d71eeaa5f468577eb253eca29f57e3577ea0a954f6991313fd71",
                "sha256:65e1ea1dc98ccb565bf8dd0f7664fc767796d3a6eecaf29b79ce7e9932517ae5"
            ]
        },
        "Metadata": {
            "LastTagTime": "2021-10-11T11:27:29.418812951+08:00"
        }
    }
]

3、使用当前容器制作镜像

8f748061c863：容器ID
docker commit -a Raven -m "测试 commit 命令" 8f748061c863 mynginx:v2

image.png

4、推送镜像到阿里云镜像仓库（没有账号需要提前注册号）

遇到Get https://registry.cn-hangzhou.aliyuncs.com/v2/: unauthorized: authentication required

解决方案：把--username=re****中*****用户名补全

操作指南-一定要将需要推送的镜像重命名后推送到指定仓库

阿里云镜像仓库.png

5、export 操作容器 / import

• docker export 导出的文件被 import 导入以后变成镜像，并不能直接启动容器，需要知道之前的启动命令（docker ps --no-trunc），然后再用下面启动。或者 docker image inspect 看之前的镜像，把之前镜像的 Entrypoint 的所有和 Cmd 的连接起来就能得到启动命令

docker run -d -P mynginx:v6 /docker-entrypoint.sh nginx -g 'daemon off;'

6、save / load -- 操作镜像

docker save -o busybox.tar busybox:latest 把busybox镜像保存成tar文件 
docker load -i busybox.tar 把压缩包里面的内容直接导成镜像

六、docker run 参数说明

• -d：后台运行容器，并返回容器ID
• -i：以交换模式运行容器，通常与 -t 同时使用
• -P：随机端口映射，容器内部端口随机映射到主机的端口
• -p：指定端口映射，格式为主机(宿主机)端口:容器端口
• -t：为容器重新分配一个伪输入终端，通常与-i同时使用
• --name="nginx-lb"：为容器指定一个名称
• --dns 8.8.8.8：指定容器使用的 DNS 服务器，默认和宿主一致
• --dns-search example.com：指定容器 DNS 搜索域名，默认和宿主一致
• -h "mars"：指定容器的 hostname
• -e username="ritchie"：设置环境变量
• --env-file=[]：从指定文件读入环境变量
• --cpuset="0.2" or --cpuset="0, 1, 2"：绑定容器到指定 CPU 运行
• -m：设置容器使用内存最大值
• --net="bridge"：指定容器的网络连接类型，支持 bridge / host / none / container 四种类型
• --link=[]：开放一个端口或一组端口
• --expose=[]：开放一个端口或一组端口
• --restart：指定重启策略
• --restart=awlays：总是故障重启
• --volume，-v：绑定一个券。一般格式 宿主机文件或文件夹:虚拟机文件或文件夹