【Docker】Dockerでhello wold【Docker】
Dockerでhello worldしてみる
dockerを今更ながら学習し始めました。
まずはhello world
$ docker run hello-world
Unable to find image 'hello-world:latest' locally latest: Pulling from library/hello-world d1725b59e92d: Pull complete Digest: sha256:0add3ace90ecb4adbf7777e9aacf18357296e799f81cabc9fde470971e499788 Status: Downloaded newer image for hello-world:latest Hello from Docker! This message shows that your installation appears to be working correctly. To generate this message, Docker took the following steps: 1. The Docker client contacted the Docker daemon. 2. The Docker daemon pulled the "hello-world" image from the Docker Hub. (amd64) 3. The Docker daemon created a new container from that image which runs the executable that produces the output you are currently reading. 4. The Docker daemon streamed that output to the Docker client, which sent it to your terminal. To try something more ambitious, you can run an Ubuntu container with: $ docker run -it ubuntu bash Share images, automate workflows, and more with a free Docker ID: https://hub.docker.com/ For more examples and ideas, visit: https://docs.docker.com/get-started/
dockerコマンドをterminal上から打つと
dockerクライアント（terminal）はdockerデーモンに接続する
そこでhello wolrdのイメージを探す
PC上に存在しない場合、docker hubというdocker社が管理している場所に
ネットワークを経由して取得しにいく
次にdocker hub上にhello wold imageが見つかったら
hubからimageをダウンロードしPCに保存。
保存したイメージを元にコンテナを起動する。
同じイメージが存在する場合はPCから起動するため起動が早くなる
試しにもう一度docer run コマンドを実行します。
$ docker run hello-world
Hello from Docker! This message shows that your installation appears to be working correctly. To generate this message, Docker took the following steps: 1. The Docker client contacted the Docker daemon. 2. The Docker daemon pulled the "hello-world" image from the Docker Hub. (amd64) 3. The Docker daemon created a new container from that image which runs the executable that produces the output you are currently reading. 4. The Docker daemon streamed that output to the Docker client, which sent it to your terminal. To try something more ambitious, you can run an Ubuntu container with: $ docker run -it ubuntu bash Share images, automate workflows, and more with a free Docker ID: https://hub.docker.com/ For more examples and ideas, visit: https://docs.docker.com/get-started/
docker run コマンドを紐解く
docker run コマンドでは以下の複数のコマンドが一括実行されている
image取得
docker pull
コンテナ作成
docker create
コンテナ起動
docker start
