docker インストールとTensorflowコンテナの起動

Dockerのインストール・設定とTensorflowコンテナを起動した時の手順。
Dockerインストール手順はちょくちょく変わっているようなので、最新の情報は公式ドキュメントを参照すること。

公式ドキュメントでのUbuntuへのDockerインストール手順
Get Docker for Ubuntu - Docker Documentation

Dockerインストール

sudo apt-get update
# …
# Reading package lists... Done

sudo apt-get -y install \
linux-image-extra-$(uname -r) \
linux-image-extra-virtual
# …
# Setting up linux-image-generic (4.4.0.66.70) ...
# Setting up linux-image-extra-virtual (4.4.0.66.70) ...
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
# [sudo] password for chie8842:
# OK
sudo apt-key fingerprint 0EBFCD88
# pub   4096R/0EBFCD88 2017-02-22
#       Key fingerprint = 9DC8 5822 9FC7 DD38 854A  E2D8 8D81 803C 0EBF CD88 <- 公式ドキュメント(https://docs.docker.com/engine/installation/linux/ubuntu/#install-using-the-repository)に載っているフィンガープリントと一致しているか確認すること。
uid                  Docker Release (CE deb) <docker@docker.com>
# sub   4096R/F273FCD8 2017-02-22

sudo add-apt-repository \
"deb [arch=amd64] https://download.docker.com/linux/ubuntu \
$(lsb_release -cs) \
stable"

sudo apt-get update
# …
# Reading package lists... Done
sudo apt-get install docker-ce
apt-cache madison docker-ce
#  docker-ce | 17.03.0~ce-0~ubuntu-xenial | https://download.docker.com/linux/ubuntu xenial/stable amd64 Packages
sudo docker run hello-world
# Unable to find image 'hello-world:latest' locally
# latest: Pulling from library/hello-world
# 78445dd45222: Pull complete
# BDigest: sha256:c5515758d4c5e1e838e9cd307f6c6a0d620b5e07e6f927b07d05f6d12a1ac8d7
# 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.
#  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://cloud.docker.com/

# For more examples and ideas, visit:
#  https://docs.docker.com/engine/userguide/

インストール後の設定

現在のユーザでDockerを実行できるように権限付与する

sudo groupadd docker
# groupadd: group 'docker' already exists
sudo usermod -aG docker $USER
docker run -it ubuntu bash
# docker: Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Post http://%2Fvar%2Frun%2Fdocker.sock/v1.26/containers/create: dial unix /var/run/docker.sock: connect: permission denied.

# 公式ドキュメントの通りだと、ここでdocker run に成功するはずだが、
# 上記のように失敗する。OS再起動したらうまくいくようになった。
sudo shutdown -r now
docker run -it ubuntu bash
# 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.
#  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://cloud.docker.com/

# For more examples and ideas, visit:
#  https://docs.docker.com/engine/userguide/

Dockerサービスの起動と自動起動の設定

sudo systemctl enable docker
# [sudo] password for chie8842:
# Synchronizing state of docker.service with SysV init with /lib/systemd/systemd-sysv-install...
# Executing /lib/systemd/systemd-sysv-install enable docker

sysv-rc-conf --list |grep docker
# docker       0:off      1:off   2:on    3:on    4:on    5:on    6:off
# 自動起動がONになっていない場合は、自動起動をONにする。
sudo sysv-rc-conf docker on

Tensorflowコンテナの起動

docker run -it -p 8888:8888 gcr.io/tensorflow/tensorflow # 初回はDockerイメージのダウンロードが行われるので時間がかかる
# …
#     Copy/paste this URL into your browser when you connect for the first time,
#     to login with a token:
#         http://localhost:8888/?token=******* <-このURLでブラウザを開くと、Jupyter Notebookにアクセスできる。 

開いたJupyter Notebookのキャプチャ

デフォルトでGetting StartedやMNistなどのサンプルのノートブックが入っている。