docker 入门笔记

Container 是一种轻量级的虚拟化技术，不用模拟硬件创建虚拟机。

Docker 是基于 Linux Kernel 的 Namespace、CGroups、UnionFileSystem 等技术封装成的一种自 定义容器格式，从而提供一套虚拟运行环境。

Namespace：用来做隔离的，比如 pid [进程]、net [网络]、mnt [挂载点]等。

CGroups: Controller Groups用来做资源限制，比如内存和CPU等。

Union file systems：用来做image和container分层。

 

安装依赖

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

（以下可以使用阿里云镜像速度快，参考地址：https://blog.csdn.net/DavidSoCool/article/details/102915527）

设置docker仓库

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

安装docker

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

设置开机启动

 sudo systemctl enable docker

启动docker

sudo systemctl start docker

查看版本

运行hello-world镜像生成容器，会先从本地查找，找不到去远端拉取在运行（镜像和容器的关系就像java里面的class文件和创建出来的对象）

拉取tomcat镜像，不指定版本默认拉取最新的，指定版本可以去hub.docker.com上面找，镜像名字不对会报错

查看本地镜像

运行镜像， -d 后台运行，--name 别名，-p 对外端口 9090 对内 8080，运行对应的一些环境变量参数可以去hub.docker.com看

docker run -d --name my-tomcat -p 9090:8080 tomcat

查看后台运行container

 在多创建几个tomcat的container

 查看运行的container

查看所有包括退出的container

 docker命令

Usage:	docker [OPTIONS] COMMAND

A self-sufficient runtime for containers

Options:
      --config string      Location of client config files (default "/root/.docker")
  -c, --context string     Name of the context to use to connect to the daemon (overrides DOCKER_HOST env var and default context set with
                           "docker context use")
  -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 "/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:
  builder     Manage builds
  config      Manage Docker configs
  container   Manage containers
  context     Manage contexts
  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

Commands:
  attach      Attach local standard input, output, and error streams 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 to files or directories 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

Run 'docker COMMAND --help' for more information on a command.