文章目录
- 1 docker历史
- 2 docker架构
- 3 安装docker
- 4 docker命令
- 5 docker常用命令
- 5.1 镜像常用命令
- 5.2 容器常用命令
- 5.3 docker run 命令
- 6 docker-compose
- 6.1 安装
- 6.2 卸载重装
1 docker历史
学习一门技术首先要了解它的历史。这是很必要的。docker现在是一门非常火的技术,无论是对于开发还是运维都应该掌握。
Docker 公司位于旧金山,由法裔美籍开发者和企业家 Solumon Hykes 创立;Docker 公司起初是一家名为 dotCloud 的平台即服务(Platform-as-a-Service, PaaS)提供商;
底层技术上,dotCloud 平台利用了 Linux 容器技术。为了方便创建和管理这些容器,dotCloud 开发了一套内部工具,之后被命名为“Docker”。Docker就是这样诞生的!
2013年,dotCloud 的 PaaS 业务并不景气,公司需要寻求新的突破。于是他们聘请了 Ben Golub 作为新的 CEO,将公司重命名为“Docker”,放弃dotCloud PaaS 平台,怀揣着“将 Docker 和容器技术推向全世界”的使命,开启了一段新的征程。
如今 Docker 公司被普遍认为是一家创新型科技公司,据说其市场价值约为 10 亿美元。Docker 公司已经通过多轮融资,吸纳了来自硅谷的几家风投公司的累计超过 2.4 亿美元的投资。
几乎所有的融资都发生在公司更名为“Docker”之后。
“Docker”一词来自英国口语,意为码头工人(Dock Worker),即从船上装卸货物的人。
了解完历史之后,学习一门技术最重要的是官方网站,docker的官方文档真的超级详细
docker官方文档链接:https://docs.docker.com/reference/
2 docker架构
Docker 是一个开源的应用容器引擎,让开发者可以打包他们的应用以及依赖包到一个可移植的容器中,然后发布到任何流行的Linux机器或Windows 机器上,也可以实现虚拟化,容器是完全使用沙箱机制,相互之间不会有任何接口。
一个完整的Docker有以下几个部分组成:
- DockerClient客户端
- Docker Daemon守护进程
- Docker Image镜像
- DockerContainer容器
Docker采用 C/S架构 Docker daemon 作为服务端接受来自客户的请求,并处理这些请求(创建、运行、分发容器)。 客户端和服务端既可以运行在一个机器上,也可通过 socket 或者RESTful API 来进行通信。
Docker daemon 一般在宿主主机后台运行,等待接收来自客户端的消息。 Docker 客户端则为用户提供一系列可执行命令,用户用这些命令实现跟 Docker daemon 交互。
Docker类比面向对象:
Docker | 面向对象 |
镜像 | 类 |
容器 | 对象 |
虚拟机对比Docker:
Docker | 虚拟机 | |
隔离性 | 较强 | 强 |
资源开销 | 小 | 大 |
镜像大小 | MB | GB |
启动速度 | 秒级 | 分钟级 |
3 安装docker
docker可以安装在linux多个发行版、windows和macOS,
安装过程不细节描述,如果读者需要的话请自行百度。
4 docker命令
博主的机器版本
[root@localhost ~]# uname -r
3.10.0-1160.el7.x86_64
# 查看docker是否启动
[root@localhost ~]# systemctl status docker
# 操作docker服务的其他命令
systemctl start docker # 启动docker服务
systemctl stop docker # 停止docker服务
systemctl restart docker # 重启docker服务
systemctl enable docker # 使能docker开机自启动
systemctl disable docker # 停止docker开机自启动
# 查看docker版本信息
[root@localhost ~]# docker --version
Docker version 1.13.1, build 0be3e21/1.13.1
# 查看docker信息
[root@localhost ~]# docker info
# 帮助命令
[root@localhost ~]# docker --help
Usage: docker COMMAND
A self-sufficient runtime for containers
Options:
--config string Location of client config files (default "/root/.docker")
-D, --debug Enable debug mode
--help Print usage
-H, --host list Daemon socket(s) to connect to (default [])
-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 "/root/.docker/ca.pem")
--tlscert string Path to TLS certificate file (default "/root/.docker/cert.pem")
--tlskey string Path to TLS key file (default "/root/.docker/key.pem")
--tlsverify Use TLS and verify the remote
-v, --version Print version information and quit
Management Commands:
container Manage containers
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
volume Manage volumes
Commands:
attach Attach to a running container
build Build an image from a Dockerfile
commit Create a new image from a container's changes
cp Copy files/folders between a container and the local filesystem
create Create a new container
diff Inspect changes on a container's filesystem
events Get real time events from the server
exec Run a command in a running container
export Export a container's filesystem as a tar archive
history Show the history of an image
images List images
import Import the contents from a tarball to create a filesystem image
info Display system-wide information
inspect Return low-level information on Docker objects
kill Kill one or more running containers
load Load an image from a tar archive or STDIN
login Log in to a Docker registry
logout Log out from a Docker registry
logs Fetch the logs of a container
pause Pause all processes within one or more containers
port List port mappings or a specific mapping for the container
ps List containers
pull Pull an image or a repository from a registry
push Push an image or a repository to a registry
rename Rename a container
restart Restart one or more containers
rm Remove one or more containers
rmi Remove one or more images
run Run a command in a new container
save Save one or more images to a tar archive (streamed to STDOUT by default)
search Search the Docker Hub for images
start Start one or more stopped containers
stats Display a live stream of container(s) resource usage statistics
stop Stop one or more running containers
tag Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE
top Display the running processes of a container
unpause Unpause all processes within one or more containers
update Update configuration of one or more containers
version Show the Docker version information
wait Block until one or more containers stop, then print their exit codes
5 docker常用命令
5.1 镜像常用命令
镜像由远程仓库托管,用户可以搜索、拉取、打包、删除镜像
# 搜索mysql
[root@localhost ~]# docker search mysql
______________________________________________________________________________________
INDEX NAME DESCRIPTION STARS OFFICIAL AUTOMATED
docker.io docker.io/mysql MySQL is a widely used, open-source relati... 10970 [OK]
docker.io docker.io/mariadb MariaDB Server is a high performing open s... 4148 [OK]
docker.io docker.io/mysql/mysql-server Optimized MySQL Server Docker images. Crea... 814 [OK]
docker.io docker.io/percona Percona Server is a fork of the MySQL rela... 540 [OK]
docker.io docker.io/centos/mysql-57-centos7 MySQL 5.7 SQL database server 88
docker.io docker.io/mysql/mysql-cluster Experimental MySQL Cluster Docker images. ... 85
docker.io docker.io/centurylink/mysql Image containing mysql. Optimized to be li... 59 [OK]
docker.io docker.io/bitnami/mysql Bitnami MySQL Docker Image 52 [OK]
docker.io docker.io/databack/mysql-backup Back up mysql databases to... anywhere! 44
docker.io docker.io/deitch/mysql-backup REPLACED! Please use http://hub.docker.com... 41 [OK]
docker.io docker.io/prom/mysqld-exporter 39 [OK]
docker.io docker.io/tutum/mysql Base docker image to run a MySQL database ... 35
docker.io docker.io/linuxserver/mysql A Mysql container, brought to you by Linux... 30
docker.io docker.io/schickling/mysql-backup-s3 Backup MySQL to S3 (supports periodic back... 29 [OK]
docker.io docker.io/centos/mysql-56-centos7 MySQL 5.6 SQL database server 20
docker.io docker.io/circleci/mysql MySQL is a widely used, open-source relati... 20
docker.io docker.io/mysql/mysql-router MySQL Router provides transparent routing ... 19
docker.io docker.io/arey/mysql-client Run a MySQL client from a docker container 17 [OK]
docker.io docker.io/fradelg/mysql-cron-backup MySQL/MariaDB database backup using cron t... 13 [OK]
docker.io docker.io/yloeffler/mysql-backup This image runs mysqldump to backup data u... 7 [OK]
docker.io docker.io/openshift/mysql-55-centos7 DEPRECATED: A Centos7 based MySQL v5.5 ima... 6
docker.io docker.io/devilbox/mysql Retagged MySQL, MariaDB and PerconaDB offi... 3
docker.io docker.io/ansibleplaybookbundle/mysql-apb An APB which deploys RHSCL MySQL 2 [OK]
docker.io docker.io/jelastic/mysql An image of the MySQL database server main... 1
docker.io docker.io/widdpim/mysql-client Dockerized MySQL Client (5.7) including Cu... 1 [OK]
# search指令帮助
[root@localhost ~]# docker search --help
______________________________________________________________________________________
Usage: docker search [OPTIONS] TERM
Search the Docker Hub for images
Options:
-f, --filter filter Filter output based on conditions provided
--help Print usage
--limit int Max number of search results (default 25)
--no-index Don't truncate output
--no-trunc Don't truncate output
# 按照指定条件过滤
[root@localhost ~]# docker search -f stars=3000 mysql
______________________________________________________________________________________
INDEX NAME DESCRIPTION STARS OFFICIAL AUTOMATED
docker.io docker.io/mysql MySQL is a widely used, open-source relati... 10970 [OK]
docker.io docker.io/mariadb MariaDB Server is a high performing open s... 4148 [OK]
# 查看目前所有的镜像
[root@localhost ~]# docker images
______________________________________________________________________________________
REPOSITORY TAG IMAGE ID CREATED SIZE
docker.io/redis latest 7f33e76fcb56 2 months ago 105 MB
docker.io/nginx latest 7ce4f91ef623 2 months ago 133 MB
docker.io/mysql 5.7 cd0f0b1e283d 2 months ago 449 MB
docker.io/postgres 9.4 ed5a45034282 16 months ago 251 MB
#
# 删除一个镜像,当这个镜像有运行的容器时,会提示删除失败
[root@localhost ~]# docker rmi 7f33e76fcb56
______________________________________________________________________________________
Error response from daemon: conflict: unable to delete 7f33e76fcb56 (must be forced) - image is being used by stopped container 092bba0f9933
# 查看rmi命令的可选参数
[root@localhost ~]# docker rmi --help
______________________________________________________________________________________
Usage: docker rmi [OPTIONS] IMAGE [IMAGE...]
Remove one or more images
Options:
-f, --force Force removal of the image
--help Print usage
--no-prune Do not delete untagged parents
# 强力删除镜像,不管是否有这个镜像的容器在运行
[root@localhost ~]# docker rmi -f docker_ID
# 强力递归删除所有镜像
[root@localhost ~]# docker rmi -f $(docker images)
# 拉取镜像,从远程仓库下载到本地
docker pull 镜像名[:Tag] #Tag是版本号
5.2 容器常用命令
# 查看docker ps --help
[root@localhost ~]# docker ps --help
______________________________________________________________________________________
Usage: docker ps [OPTIONS]
List containers
Options:
-a, --all Show all containers (default shows just running)
-f, --filter filter Filter output based on conditions provided
--format string Pretty-print containers using a Go template
--help Print usage
-n, --last int Show n last created containers (includes all states) (default -1)
-l, --latest Show the latest created container (includes all states)
--no-trunc Don't truncate output
-q, --quiet Only display numeric IDs
-s, --size Display total file sizes
# 查看所有的容器
[root@localhost ~]# docker ps -a
______________________________________________________________________________________
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
092bba0f9933 7f33e76fcb56 "docker-entrypoint..." 2 months ago Exited (0) 2 months ago redis-test
b3b652ece004 7ce4f91ef623 "/docker-entrypoin..." 2 months ago Exited (0) 2 months ago dockernginx
e48c6bbcad77 ed5a45034282 "docker-entrypoint..." 2 months ago Exited (0) 2 months ago pgsql
e7067011b293 cd0f0b1e283d "docker-entrypoint..." 2 months ago Exited (0) 18 minutes ago dockermysql
# 查看所有的容器 只显示ID
[root@localhost ~]# docker ps -aq
______________________________________________________________________________________
092bba0f9933
b3b652ece004
e48c6bbcad77
e7067011b293
# 查看正在运行的容器
[root@localhost ~]# docker ps
______________________________________________________________________________________
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
e7067011b293 cd0f0b1e283d "docker-entrypoint..." 2 months ago Up 3 seconds 33060/tcp, 0.0.0.0:3307->3306/tcp dockermysql
# 删除一个容器(not running)
[root@localhost ~]# docker rm docker_ID
# 强制删除一个容器
[root@localhost ~]# docker rm -f docker_ID
# 递归删除所有容器
[root@localhost ~]# docker rm $(docker ps -aq)
092bba0f9933
b3b652ece004
e48c6bbcad77
# 运行一个容器(还没有实例化)
[root@localhost ~]# docker run 镜像名
______________________________________________________________________________________
# 启动一个已经实例化的容器
[root@localhost ~]# docker start 容器ID
[root@localhost ~]# docker start dockermysql
dockermysql
[root@localhost ~]# docker ps
______________________________________________________________________________________
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
e7067011b293 cd0f0b1e283d "docker-entrypoint..." 2 months ago Up 3 seconds 33060/tcp, 0.0.0.0:3307->3306/tcp dockermysql
[root@localhost ~]# docker stop dockermysql
dockermysql
# 停止一个正在运行的容器
[root@localhost ~]# docker stop 容器ID
5.3 docker run 命令
docker run也是一种容器命令,为什么单独拿出来说,就是因为太重要。
# 查看docker run命令的帮助
[root@localhost ~]# docker run --help
Usage: docker run [OPTIONS] IMAGE [COMMAND] [ARG...]
Run a command in a new container
Options:
--add-host list Add a custom host-to-IP mapping (host:ip) (default [])
-a, --attach list Attach to STDIN, STDOUT or STDERR (default [])
--blkio-weight uint16 Block IO (relative weight), between 10 and 1000, or 0 to disable (default 0)
--blkio-weight-device weighted-device Block IO weight (relative device weight) (default [])
--cap-add list Add Linux capabilities (default [])
--cap-drop list Drop Linux capabilities (default [])
--cgroup-parent string Optional parent cgroup for the container
--cidfile string Write the container ID to the file
--cpu-count int CPU count (Windows only)
--cpu-percent int CPU percent (Windows only)
--cpu-period int Limit CPU CFS (Completely Fair Scheduler) period
--cpu-quota int Limit CPU CFS (Completely Fair Scheduler) quota
--cpu-rt-period int Limit CPU real-time period in microseconds
--cpu-rt-runtime int Limit CPU real-time runtime in microseconds
-c, --cpu-shares int CPU shares (relative weight)
--cpus decimal Number of CPUs (default 0.000)
--cpuset-cpus string CPUs in which to allow execution (0-3, 0,1)
--cpuset-mems string MEMs in which to allow execution (0-3, 0,1)
--credentialspec string Credential spec for managed service account (Windows only)
-d, --detach Run container in background and print container ID
--detach-keys string Override the key sequence for detaching a container
--device list Add a host device to the container (default [])
--device-read-bps throttled-device Limit read rate (bytes per second) from a device (default [])
--device-read-iops throttled-device Limit read rate (IO per second) from a device (default [])
--device-write-bps throttled-device Limit write rate (bytes per second) to a device (default [])
--device-write-iops throttled-device Limit write rate (IO per second) to a device (default [])
--disable-content-trust Skip image verification (default true)
--dns list Set custom DNS servers (default [])
--dns-option list Set DNS options (default [])
--dns-search list Set custom DNS search domains (default [])
--entrypoint string Overwrite the default ENTRYPOINT of the image
-e, --env list Set environment variables (default [])
--env-file list Read in a file of environment variables (default [])
--expose list Expose a port or a range of ports (default [])
--group-add list Add additional groups to join (default [])
--health-cmd string Command to run to check health
--health-interval duration Time between running the check (ns|us|ms|s|m|h) (default 0s)
--health-retries int Consecutive failures needed to report unhealthy
--health-timeout duration Maximum time to allow one check to run (ns|us|ms|s|m|h) (default 0s)
--help Print usage
-h, --hostname string Container host name
--init Run an init inside the container that forwards signals and reaps processes
--init-path string Path to the docker-init binary
-i, --interactive Keep STDIN open even if not attached
--io-maxbandwidth string Maximum IO bandwidth limit for the system drive (Windows only)
--io-maxiops uint Maximum IOps limit for the system drive (Windows only)
--ip string Container IPv4 address (e.g. 172.30.100.104)
--ip6 string Container IPv6 address (e.g. 2001:db8::33)
--ipc string IPC namespace to use
--isolation string Container isolation technology
--kernel-memory string Kernel memory limit
-l, --label list Set meta data on a container (default [])
--label-file list Read in a line delimited file of labels (default [])
--link list Add link to another container (default [])
--link-local-ip list Container IPv4/IPv6 link-local addresses (default [])
--log-driver string Logging driver for the container
--log-opt list Log driver options (default [])
--mac-address string Container MAC address (e.g. 92:d0:c6:0a:29:33)
-m, --memory string Memory limit
--memory-reservation string Memory soft limit
--memory-swap string Swap limit equal to memory plus swap: '-1' to enable unlimited swap
--memory-swappiness int Tune container memory swappiness (0 to 100) (default -1)
--name string Assign a name to the container
--network string Connect a container to a network (default "default")
--network-alias list Add network-scoped alias for the container (default [])
--no-healthcheck Disable any container-specified HEALTHCHECK
--oom-kill-disable Disable OOM Killer
--oom-score-adj int Tune host's OOM preferences (-1000 to 1000)
--pid string PID namespace to use
--pids-limit int Tune container pids limit (set -1 for unlimited)
--privileged Give extended privileges to this container
-p, --publish list Publish a container's port(s) to the host (default [])
-P, --publish-all Publish all exposed ports to random ports
--read-only Mount the container's root filesystem as read only
--restart string Restart policy to apply when a container exits (default "no")
--rm Automatically remove the container when it exits
--runtime string Runtime to use for this container
--security-opt list Security Options (default [])
--shm-size string Size of /dev/shm, default value is 64MB
--sig-proxy Proxy received signals to the process (default true)
--stop-signal string Signal to stop a container, SIGTERM by default (default "SIGTERM")
--stop-timeout int Timeout (in seconds) to stop a container
--storage-opt list Storage driver options for the container (default [])
--sysctl map Sysctl options (default map[])
--tmpfs list Mount a tmpfs directory (default [])
-t, --tty Allocate a pseudo-TTY
--ulimit ulimit Ulimit options (default [])
-u, --user string Username or UID (format: <name|uid>[:<group|gid>])
--userns string User namespace to use
--uts string UTS namespace to use
-v, --volume list Bind mount a volume (default [])
--volume-driver string Optional volume driver for the container
--volumes-from list Mount volumes from the specified container(s) (default [])
-w, --workdir string Working directory inside the container
MySQL为例说明run命令的实际应用
确保本地已经拉取到了mysql的镜像
docker run --name docker5.7.1 -p 3310:3306 -e MYSQL_ROOT_PASSWORD=root -d mysql:5.7
--name # 给实例起一个名字
-p # 端口映射 宿主机端口:容器端口
-e # 环境变量
-d # 后台启动
通过宿主机IP:PORT连接到docker镜像的mysql服务器
通过挂载将镜像中的数据同步到宿主机中,比如mysql的配置文件和数据文件,可以在宿主机中做配置,并且把数据备份到宿主机中。
-v 宿主机文件目录:容器文件目录
6 docker-compose
6.1 安装
Linux系统安装操作步骤
下载
curl -L "https://github.com/docker/compose/releases/download/1.29.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
添加权限
chmod +x /usr/local/bin/docker-compose
添加软连接
ln -s /usr/local/bin/docker-compose /usr/bin/docker-compose
查看版本,如果安装成功会出现版本信息
docker-compose --version
其他操作系统安装请参考官方链接:
https://docs.docker.com/compose/install/
6.2 卸载重装
如果出现下面所示的报错
[root@localhost composetest]# docker-compose up
Building web
unknown flag: --iidfile
See 'docker build --help'.
ERROR: Service 'web' failed to build : Build failed
卸载1.29.1 版本 下载1.26.2版本
[root@localhost composetest]# rm -f /usr/local/bin/docker-compose
[root@localhost composetest]# curl -L "https://github.com/docker/compose/releases/download/1.26.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose && chmod +x /usr/local/bin/docker-compose
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 633 100 633 0 0 588 0 0:00:01 0:00:01 --:--:-- 588
100 11.6M 100 11.6M 0 0 216k 0 0:00:55 0:00:55 --:--:-- 1182k
[root@localhost composetest]# docker-compose --version
docker-compose version 1.26.2, build eefe0d31
[root@localhost composetest]# docker-compose up
Building web
Step 1/10 : FROM python:3.7-alpine
---> 0217c3d2f165
Step 2/10 : WORKDIR /code
# 解决问题