基本指令操作

常用指令
# List running containers
docker ps

# ssh into the container
docker exec -it <container-name> /bin/sh

# Restart a container
docker restart <container-name>

#Show running container stats
docker stats

# Check docker daemon disk space usage
docker system df

# Purge those unused images, networks, containers and volumes 
docker system prune

# Check the container log
docker logs <container-name>

# Seacrh docker registry for image
docker search <image-name>

# Create and start a container
docker run -it <image-name> /bin/bash

# Check container's exposed ports
docker port {container-name}
線上求助
man docker <command>
man docker build
man docker rmi 
管理 Images
## 搜尋 Docker Hub 上的 image name
docker search lamp

## 顯示已下載所有 image name
docker images

## 檢視既有 image 的詳細資訊
docker inspect <image-name>

## 網路下載 image
docker pull ubuntu:13.10

## 刪除已下載的 image
docker rmi <image-name>

## 刪除所有 images
docker rmi $(docker images -q)

## 刪除所有 images,除了 my-images 以外
docker rmi $(docker images | grep -v 'ubuntu\|my-image' | awk {'print $3'})

## 刪除所有 <none> 的有問題 images
docker rmi $(docker images -f "dangling=true" -q)

## 刪除與 myapp/myimage 相關的 <none> 的 images
docker rmi $(docker images myapp/myimage -f "dangling=true" -q)

## 列出所有 images 之間繼承的關係
docker run --rm -v /var/run/docker.sock:/var/run/docker.sock nate/dockviz images -t
管理 Containers
## 開啟並進入 container 的 console
docker run -it <image-name> /bin/bash
docker run -it --name <container-name> <image-name> /bin/bash

## 以 daemon 方式啟動 container
docker run -d -p 11180:80 <image-name>
docker run -d --name web <image-name>
TIP: 啟動 container 時可以自訂名稱以方便管理

docker run -d -p 80:80 --rm <image-name>
加上 --rm 時,當停止 container 時,會自動被刪除(與 docker rm 指令相同),且無法使用啟動指令
(docker start) 只能使用 docker run 啟動。 

## 檢查目前已經啟動的 containers
docker ps
docker ps -a

## 檢視開啟中 container 的詳細資訊,包含 Volumes、IP、Hostname 等等
docker inspect <container-id>

## 刪除指定的 container
docker rm <container-id> 

## 刪除所有的 containers
NOTE: 小心,這也會刪除正在執行的 container
docker ps -a -q | xargs -n 1 docker rm
docker rm $(docker ps -aq) 

## 刪除所有已經終止的 container
docker ps -a | grep "Exited" | awk '{print $1}' | xargs docker rm
docker rm $(docker ps --all -q -f status=exited)
NOTE: 這常用於在重新啟動 container 或 rebuild image 時遇到錯誤訊息的解決方法。

## 停止 container
docker stop <container-id>

## Stop all containers
docker stop $(docker ps -aq)
docker ps -aq | xargs docker stop

## 匯出 container
docker export <container-id>  > ubuntu-mysql.tar 

## 匯入 container
cat ubuntu-mysql.tar | docker import - <image-name>

## 跳離目前開啟中的 container
按下 Ctrl P 後再按 Ctrl Q
NOTE: 如果無法成功跳離,原因可能是 Ctrl+P 是 Bash 內定的快捷鍵(回到前一個指令)

## 重新進入開啟中的 container
docker attach <container-id>
或
docker attach <container-name>
如果 container 是以 daemon 啟動,改用以下方式
docker exec -it <container-id/name> /bin/bash

## 儲存開啟中 container 內容
docker commit <container-id> <image-name> 

## 顯示指定 container 的 IP
docker inspect <container-id> | grep IPAddress | cut -d '"' -f 4 

Check Container CPU and RAM Usage

docker stats
docker stats --no-stream
docker stats --no-stream -a
docker stats <container-name>
docker stats --format "table {{.Container}}\t{{.CPUPerc}}\t{{.MemPerc}}"
docker ps --no-trunc --format "{{.Names}}\t{{.ID}}"

 

複製/搬移 container 至另一部主機
## Stop the container
docker stop <container-name>

## Save container image
docker commit <container-name> mycontainerimage
docker save mycontainerimage | gzip > mycontainerimage.tar.gz

## Load container image to destination host
gunzip -c mycontainerimage.tar.gz | docker load 

## Transfer image without creating a file
docker save mycontainerimage | gzip | ssh root@203.0.113.1 'gunzip | docker load'

TIP:
執行 exit 可以離開目前的 container,回到原先的 Linux

一旦離開 container,所有之前做過的變更,將全部失效,如果要保留做過的變更,必須使用 commit 產生一個新的 image。

-p 將 Host 的 port 11180 轉送至 container 的 port 80

管理 Volumes

Docker 的 Data Volume 是一個很特別的目錄設計,主要用在不同 containers 之間的資料分享,永久保存資料等。

主要特點:

// 啟用 volume
docker run -t -i -p 80:80 -v ${PWD}/webapp:/webapp alang/centos5-lamp_php51

TIP:
格式:-v <host-dir>:<container-dir>

在 container 內會自動新增一個目錄名為 /webapp,儲存到這個目錄的所有資料都會被保留。

被保留的資料會儲存到 host 的某個特定目錄內,即使 container 被移除,這些資料還是會存在,要如何找到這個特定目錄:

docker inspect -f {{.Volumes}} <container-id>

一般預設會是
/var/lib/docker/vfs/dir/bfebd8cb6......


Docker Network
# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                                      NAMES
7ccaf6119fa8        nginx:latest        "nginx -g 'daemon of…"   2 days ago          Up 39 hours         0.0.0.0:80->80/tcp, 0.0.0.0:443->443/tcp   nginx_mysql_web_1
81a920bb51a6        nginx_mysql_php     "docker-php-entrypoi…"   2 days ago          Up 2 days           9000/tcp                                   nginx_mysql_php_1
437a7501198f        mariadb:10.3        "docker-entrypoint.s…"   2 days ago          Up 2 days           3306/tcp                                   nginx_mysql_db_1

# docker network ls
NETWORK ID          NAME                  DRIVER              SCOPE
852eff02220e        bridge                bridge              local
334d2b8571a4        host                  host                local
b97cae66a977        nginx_mysql_default   bridge              local
40d15afb34b4        none                  null                local

# docker network inspect -f '{{json .IPAM.Config}}' bridge | jq -r .[].Subnet
# docker network inspect -f '{{json .IPAM.Config}}' bridge | jq -r .[].Gateway

# brctl show
bridge name     bridge id               STP enabled     interfaces
br-b97cae66a977         8000.0242569e79ff       no              veth3ce8cbd
                                                        veth5129652
                                                        veth55dcdf7
docker0         8000.0242faff70bb       no

取得 container IP

## Method #1: By inspecting the container
docker inspect <container_id> | grep -i ipaddr
docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' <container_id>

# get an IP address associated with a specific network
# docker container inspect -f '{{ .NetworkSettings.Networks.<NETWORK NAME>.IPAddress }}' <CONTAINER_ID_OR_NAME>
docker container inspect -f '{{ .NetworkSettings.Networks.bridge.IPAddress }}' ubuntu-ip

## Method #2: Using the container's shell
docker exec -it <container-name> sh
> ip
or
> ifconfig

# if you get the errors with 'command not found', following the below steps to install the relevant packages.
> apt update -qq
> apt install iproute2 -yqq

## Method #3: By inspecting the network itself
# docker network inspect <NETWORK NAME>
docker network inspect bridge | jq .[].Containers
docker network inspect bridge | jq '.[].Containers."<CONTAINER ID>".IPv4Address'

docker network inspect -f '{{json .Containers}}' bridge | \
jq '..|if type == "object" and has("Name") then select(.Name=="<CONTAINER NAME>") | .IPv4Address else empty end' -r
管理 Docker

檢查版本資訊

# 檢查 Docker 版本
docker version

# Docker 更多資訊
docker info

host 與 container 間交換檔案

docker cp <container-name>:/etc/nginx/nginx.conf /data/web/conf
docker cp host_source_path my_container:destination_path
docker cp -a host_source_path my_container:destination_path

定期清除沒用的物件

# 這會清除所有已停止的 container,沒有在用的docker層網路介面與 <none> 不完整的 image。
docker images --quiet --filter "dangling=true"
docker system prune

# 上述指令會保留 volume 裡的資料,如果要一併清除,須加上 --volumes
docker system prune -a --volumes

# For volumes only
docker volume ls -f dangling=true
docker volume prune
Restart Policy

自動啟動 container

# Add --restart=unless-stopped
docker run -d -p 4449:4449 --name myst --restart=unless-stopped 
Docker Logging
docker logs {container-name}
docker logs --tail 50 {container-name}
docker logs -f {container-name}
docker logs -f --tail 20 {container-name}

# View timestamp in Docker logs
docker logs -t {container-name}
docker -n=10 -t {container-name}

# Viewing Docker logs in a specified time period
docker logs --since 1440m -t {container-name}
docker logs --until 1440m -t {container-name}
docker logs --since 2021-07-28 -t {container-name} 

Docker system service logs

sudo journalctl -u docker

Where are Docker logs stored

sudo ls -lh /var/lib/docker/containers

Enabling Log Rotation for Docker (JSON)

Edit /etc/docker/daemon.json

{
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "10m",
    "max-file": "3" 
  }
}

Restart Docker daemon

sudo systemctl restart docker
Disk Space Usage
avimanyu@iborg-desktop:~$ docker system df
TYPE            TOTAL     ACTIVE    SIZE      RECLAIMABLE
Images          4         4         1.065GB   0B (0%)
Containers      4         4         5.705kB   0B (0%)
Local Volumes   7         7         1.108GB   0B (0%)
Build Cache     0         0         0B        0B
avimanyu@iborg-desktop:~$ docker system df -v
Images space usage:

REPOSITORY                               TAG       IMAGE ID       CREATED         SIZE      SHARED SIZE   UNIQUE SIZE   CONTAINERS
ghost                                    4.32.0    b40265427368   8 weeks ago     468.8MB   0B            468.8MB       1
jrcs/letsencrypt-nginx-proxy-companion   latest    037cc4751b5a   13 months ago   24.35MB   0B            24.35MB       1
jwilder/nginx-proxy                      latest    509ff2fb81dd   15 months ago   165MB     0B            165MB         1
mariadb                                  10.5.3    f5d2bcaf057b   20 months ago   407MB     0B            407MB         1

Containers space usage:

CONTAINER ID   IMAGE                                    COMMAND                  LOCAL VOLUMES   SIZE      CREATED        STATUS        NAMES
899cc90e85d9   ghost:4.32.0                             "docker-entrypoint.s…"   1               0B        8 weeks ago    Up 8 weeks    ghost_ghost_6
17b58fdafbce   jrcs/letsencrypt-nginx-proxy-companion   "/bin/bash /app/entr…"   4               571B      3 months ago   Up 2 months   letsencrypt-proxy-companion
58f99f46ee03   jwilder/nginx-proxy                      "/app/docker-entrypo…"   5               5.13kB    3 months ago   Up 2 months   jwilder-nginx-proxy
fb907286b60e   mariadb:10.5.3                           "docker-entrypoint.s…"   1               2B        3 months ago   Up 2 months   ghost_db_1

Local Volumes space usage:

VOLUME NAME                      LINKS     SIZE
ghostdb                          1         434.7MB
jwilder-nginx-with-ssl_acme      2         36.09kB
jwilder-nginx-with-ssl_certs     2         25.12kB
jwilder-nginx-with-ssl_dhparam   1         1.525kB
jwilder-nginx-with-ssl_html      2         1.106kB
jwilder-nginx-with-ssl_vhost     2         556B
ghost                            1         674MB

Build cache usage: 0B

CACHE ID   CACHE TYPE   SIZE      CREATED   LAST USED   USAGE     SHARED
avimanyu@iborg-desktop:~$ docker image ls
REPOSITORY    TAG       IMAGE ID       CREATED         SIZE
busybox       latest    beae173ccac6   6 weeks ago     1.24MB
ubuntu        latest    fb52e22af1b0   5 months ago    72.8MB
alpine        latest    49f356fa4513   10 months ago   5.61MB
hello-world   latest    d1165f221234   11 months ago   13.3kB
avimanyu@iborg-desktop:~$ docker ps --size
CONTAINER ID   IMAGE     COMMAND      CREATED         STATUS         PORTS     NAMES           SIZE
1171dcfb7e06   alpine    "sleep 10"   10 months ago   Up 9 seconds   
# Overlay2 is the default Docker storage driver on Ubuntu. 
# You can confirm this by running the 'docker info' command and looking for the Storage Drive
# To get the <<hash-named-directory> by the command 'docker inspect <image-name>'
sudo du -sh /var/lib/docker/overlay2/<hash-named-directory>/
# Specific Volume Disk Usage
$ docker volume ls
DRIVER    VOLUME NAME
local     d502589845f7ae7775474bc01d8295d9492a6c26db2ee2c941c27f3cac4449d1
local     e71ee3960cfef0a133d323d146a1382f3e25856480a727c037b5c81b5022cb1b
local     test-data

$ sudo du -sh /var/lib/docker/volumes/test-data/_data
4.0K	/var/lib/docker/volumes/test-data/_data
FAQ

無法移除 image

rror response from daemon: conflict: unable to delete dd78a816fb76 (must be forced) - image is referenced in multiple repositories

Solution: 如果同一個 image id 有兩個不同 image 名稱,在刪除這個 image id 時可能會遇到類似的錯誤訊息,刪除指令可以改用 image 名稱試試。

root@greencloud-us-1TB:~/watchtower# docker images
REPOSITORY                         TAG       IMAGE ID       CREATED         SIZE
mysteriumnetwork/myst              latest    5c613786d102   39 hours ago    53.3MB
presearch/node                     latest    27216957eb08   10 days ago     69.8MB
storjlabs/storagenode              latest    0ac3b4808897   3 weeks ago     124MB
lscr.io/linuxserver/transmission   latest    8cad68f9dac4   7 months ago    95.7MB
containrrr/watchtower              latest    333de6ea525a   8 months ago    16.9MB
jellyfin/jellyfin                  latest    0aa773b67433   13 months ago   717MB
presearch/auto-updater             latest    dd78a816fb76   17 months ago   16.4MB    <===
containrrr/watchtower              <none>    dd78a816fb76   17 months ago   16.4MB  <===
storjlabs/watchtower               latest    6af6621e20c1   2 years ago     14.3MB
nate/dockviz                       latest    93b5259c1e18   4 years ago     6.61MB


root@greencloud-us-1TB:~/watchtower# docker rmi dd78a816fb76
Error response from daemon: conflict: unable to delete dd78a816fb76 (must be forced) - image is referenced in multiple repositories


root@greencloud-us-1TB:~/watchtower# docker rmi presearch/auto-updater containrrr/watchtower
Untagged: presearch/auto-updater:latest
Untagged: presearch/auto-updater@sha256:3283e0b5be326d77ff4f4e8b7a91d46aaa1d511c74877b5a32f161548812d00c
Untagged: containrrr/watchtower:latest
Untagged: containrrr/watchtower@sha256:bbf9794a691b59ed2ed3089fec53844f14ada249ee5e372ff0e595b73f4e9ab3
Deleted: sha256:333de6ea525af9137e1f14a5c1bfaa2e730adca97ab97f74d738dfa99967f14f
Deleted: sha256:f493af3d0a518d307b430e267571c926557c85222217a8707c52d1cf30e3577e
Deleted: sha256:62651dc7e144aa8c238c2c2997fc499cd813468fbdc491b478332476f99af159
Deleted: sha256:83fe5af458237288fe7143a57f8485b78691032c8c8c30647f8a12b093d29343

Revision #30
Created 19 June 2020 11:46:01 by Admin
Updated 12 April 2023 12:00:22 by Admin