下半年正式啟動Docker系列，跟著Udemy Docker captain學!

紀錄7/2 Docker讀書會系列-Part1

Docker 簡言

擷取What Does Docker Do, and When Should You Use It?內容

Docker is a tool for running your applications inside containers

Docker is similar in concept to virtual Machines, except it’s much more lightweight

Docker會將應用程式和應用程式所需的環境包一起!

Docker Image

用來建立Container
唯讀

Docker Container

利用Image執行出來的程序
建立在Image層上
跟主機共用OS

體驗Docker-免安裝

Docker playground

登入後»>ADD NEW INSTANCE

可以先稍微體驗Docker

docker playground

基本指令

官方文件整理的基本指令

docker version

Client: Docker Engine - Community
 Version:           19.03.11
 API version:       1.40
 Go version:        go1.13.10
 Git commit:        42e35e61f3
 Built:             Mon Jun  1 09:09:53 2020
 OS/Arch:           linux/amd64
 Experimental:      true

Server: Docker Engine - Community
 Engine:
  Version:          19.03.11
  API version:      1.40 (minimum version 1.12)
  Go version:       go1.13.10
  Git commit:       42e35e61f3
  Built:            Mon Jun  1 09:16:24 2020
  OS/Arch:          linux/amd64
  Experimental:     true
 containerd:
  Version:          v1.2.13
  GitCommit:        7ad184331fa3e55e52b890ea95e65ba581ae3429
 runc:
  Version:          1.0.0-rc10
  GitCommit:        dc9208a3303feef5b3839f4323d9beb36df0a9dd
 docker-init:
  Version:          0.18.0
  GitCommit:        fec3683

docker info

Client:
 Debug Mode: false
 Plugins:
  app: Docker App (Docker Inc., v0.9.1-beta3)

Server:
 Containers: 0
  Running: 0
  Paused: 0
  Stopped: 0
 Images: 0
 Server Version: 19.03.11
 Storage Driver: overlay2
  Backing Filesystem: xfs
  Supports d_type: true
  Native Overlay Diff: true
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 7ad184331fa3e55e52b890ea95e65ba581ae3429
 runc version: dc9208a3303feef5b3839f4323d9beb36df0a9dd
 init version: fec3683
 Security Options:
  apparmor
  seccomp
   Profile: default
 Kernel Version: 4.4.0-184-generic
 Operating System: Alpine Linux v3.12 (containerized)
 OSType: linux
 Architecture: x86_64
 CPUs: 8
 Total Memory: 31.4GiB
 Name: node1
 ID: W4YJ:PZGI:Z3OV:S2PV:XJCT:MALD:44WG:AMJ3:SZEM:XD4U:RICS:C56N
 Docker Root Dir: /var/lib/docker
 Debug Mode: true
  File Descriptors: 23
  Goroutines: 42
  System Time: 2020-07-04T10:17:06.957652063Z
  EventsListeners: 0
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: true
 Insecure Registries:
  127.0.0.1
  127.0.0.0/8
 Live Restore Enabled: false
 Product License: Community Engine

WARNING: API is accessible on http://0.0.0.0:2375 without encryption.
         Access to the remote API is equivalent to root access on the host. Refer
         to the 'Docker daemon attack surface' section in the documentation for
         more information: https://docs.docker.com/engine/security/security/#docker-daemon-attack-surface
WARNING: No swap limit support
WARNING: bridge-nf-call-iptables is disabled
WARNING: bridge-nf-call-ip6tables is disabled

run

在Docker 1.13以前只有支援docker run這種寫法

docker run»> 建立一個新的container，並啟動它

docker run= /containers/create + /containers(id)/start

cli command 後來寫法進化(?)成 docker COMMAND SUBCOMMAND的結構

參考Introducing Docker 1.13

docker container run --publish 80:80 nginx

白話:

要利用nginx這個image檔啟動一個container

會先從本機中找有沒有名為nginx的image，沒有的話再到Docker hub上找

run Options

--name test

將run起來的container取名，沒給的話docker隨機給你一個

--publish host machine port:container TCP port

實體主機Port(對外):Container port(內部)

啟動的container若要被其他Host/Container使用!

docker container interaction

圖摘自Run API Portal in Docker containers

--detach, -d

在背景執行container，並印出container ID

其他

docker containe ls -aordocker ps -a

列出所有的containers

$ docker container ls
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                NAMES
dd7663ffae5e        nginx               "/docker-entrypoint.…"   10 seconds ago      Up 9 seconds        0.0.0.0:80->80/tcp   sad_mcnulty

ps. sad_mcnulty為隨機給的container name

docker container logs [container id/ container name]

$ docker container logs dd7
/docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
/docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
/docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
10-listen-on-ipv6-by-default.sh: Getting the checksum of /etc/nginx/conf.d/default.conf
10-listen-on-ipv6-by-default.sh: Enabled listen on IPv6 in /etc/nginx/conf.d/default.conf
/docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh
/docker-entrypoint.sh: Configuration complete; ready for start up

ps. container 不用全打，可以識別就好

docker container stop [container id/container name]

docker container start [container id/container name]

docker container rm [container id/container name]

進階docker container rm $(docker ps -a -q)/$(docker container ls -a -q)

會刪除所有停止的container，docker ps -a -q會回傳所有存在的container id

將結果pass給rm 指令去執行刪除! rm一樣可以加上--force,-f強制執行

執行中的container不會被刪掉~

docker exec

在執行中的container中run command

進入container的shell中!

ex:docker container exec -it [container] command

$ docker container exec -it dd7 bash
root@dd7663ffae5e:/# pwd
/
root@dd7663ffae5e:/# ls
bin                   etc    mnt   sbin  var
boot                  home   opt   srv
dev                   lib    proc  sys
docker-entrypoint.d   lib64  root  tmp
docker-entrypoint.sh  media  run   usr
root@dd7663ffae5e:/#

--interactive,-i Keep STDIN 標準輸入

--tty,-t Allcate a pseudo-TTY

延伸閱讀&參考網站

What Does Docker Do, and When Should You Use It?

虛擬機與Docker有何不同？

Shan | 日常筆記

[Docker]讀書會Part1