Docker Command and Dockerfile

映象相關命令

# 下載映象

docker pull xxx

# 搜素映象

docker search xxx

# 檢視已經下載了哪些映象

docker images

# 檢視已下載映象的id

docker images -q 

# 刪除映象

docker rmi containerId/SOURCE_IMAGE[:TAG]

#刪除所有映象

docker rmi $(docker images -q)

docker images -q | xargs docker rmi 

# 刪除tag為<none>的映象

docker rmi | xargs docker images | awk '{if ($2 == "<none>" )print $3}' | xargs docker rmi -f

容器相關的命令

# 載入一個本地映象

docker load -i tomcat-8.0-jre.tar

# 啟動一個容器

docker run -dp 8080:8080 tomcat-8.0-jre --name tomcat

# 檢視正在執行的容器

docker ps

# 檢視全部容器的id

docker ps -q

# 檢視全部容器

docker ps -a

#執行 重啟 停止 殺掉容器

docker start/restart/stop/kill containerId/name

# 刪除已建立的容器

docker rm containerId/name:tag

docker rm $(docker ps -q)

# 檢視日誌

docker logs containerId/name

# 實時顯示日誌

docker logs -tf containerId/name

# 行首新增時間 的日誌

docker logs -tail  5 containerId/name

# 檢視容器資源情況

docker top containerId

# 進入容器的互動模式

docker exec -it containerId bash

# 複製 容器中的檔案、目錄到 宿主機

docker cp containerId:/root/test.txt /root/

# 複製 宿主機的檔案、目錄到 容器中

docker cp a.txt containerId:/root/

# 打包一個映象

docker commit -m "description xx" -a "author" containerId SOURCE_IMAGE[:TAG]

docker save redis:latest -o redis-cluster.tar

# 上傳到docker hub倉庫

docker tag redis:latest docker.io/whalefall541/redis:0.01

docker push docker.io/whalefall541/redis:0.01

# 檢視docker 網路配置

docker network ls

# 建立自定義網橋

docker mynetwork create mynetwork

# 將容器指定到 建立的網橋上

docker run -dp 80:80 --network mynetwork redis

# 刪除網橋

docker newnetwork rm mynetwork

# 檢視網橋

docker inpsect mynetwork

# 資料卷指定

# docker run -dp 80:80 tomcat -v /root/webapps:/root/webapps

docker run -dp 80:80 tomcat -v aa:/root/webapps

# 資料卷建立

docker volume create volume_1

# 刪除所有未使用的卷

docker volume prune

docker rm volume_1

# 檢視資料卷

docker inspect volume_1

Dockerfile

• ADD
• COPY
• ENV
• EXPOSE
• FROM
• LABEL
• STOPSIGNAL
• USER
• VOLUME
• WORKDIR
• ONBUILD (when combined with one of the supported instructions above)

詳細教程請看官網[Dockerfile][https://docs.docker.com/engine/reference/builder/]

此處摘自官網CMD和ENTRYPOINT互動

Understand how CMD and ENTRYPOINT interact

Both CMD and ENTRYPOINT instructions define what command gets executed when running a container.

There are few rules that describe their co-operation.

1. Dockerfile should specify at least one of CMD or ENTRYPOINT commands.

2. ENTRYPOINT should be defined when using the container as an executable.

3. CMD should be used as a way of defining default arguments for an ENTRYPOINT command
   
   or for executing an ad-hoc command in a container.

4. CMD will be overridden when running the container with alternative arguments.

The table below shows what command is executed for different ENTRYPOINT / CMD combinations:

Note

If CMD is defined from the base image, setting ENTRYPOINT will

reset CMD to an empty value. In this scenario, CMD must be defined in the

current image to have a value.

You can override the ENTRYPOINT setting using --entrypoint,

but this can only set the binary to exec (no sh -c will be used).

一個簡單的案例

拷貝springboot檔案到 容器並 指定spring配置檔案執行

FROM java

ENV JARNAME="demo-0.0.1-SNAPSHOT.jar"

WORKDIR /root/app

RUN /bin/bash -c "echo 'aaaa' >> 1.txt"

EXPOSE 80

VOLUME ["/root/app"]

ENTRYPOINT ["java","-jar","demo-0.0.1-SNAPSHOT.jar", "-Dspring.config.location"]

# 注意此處的引數 覆蓋時要制定容器內 或者容器能訪問到的位置才行

CMD ["application.yml"]

#ENTRYPOINT ["echo","/root"]

#CMD ["/root/app"]

docker build -t springboot:0.01 .

docker run -v /dockerlearn/dockerfilelearn:/root/app -p 80:80 --network rediscluster_default --rm springboot:0.01

Note

1. 如果 ENTRYPOINT ["exec_entry", "p1_entry"] 後面還有
   
   **CMD ["p1_cmd", "p2_cmd"]** 那麼CMD中的引數將全部追加到 ENTRYPOINT
   
   當docker run 後面跟引數時會覆蓋掉CMD中的引數
2. CMD ENTRYPOINT 陣列形式 都是exec模式，不支援解析本地變數
   
   如果想解析 使用這個命令 ENTRYPOINT ["sh","-c","java -jar $JARNAME"]
3. 如果使用了ENTRYPOINT ["sh","-c",..] 或者直接使用 ENTRYPOINT "echo Hello world"
   
   那麼直接就無法覆蓋引數了

參考文獻

1. [Dockerfile][https://docs.docker.com/engine/reference/builder/]
2. (https://docs.docker.com/engine/reference/builder/#understand-how-cmd-and-entrypoint-interact)