[LINUX] Introduction to docker Create ubuntu environment in ubuntu

Purpose

It may not be a major way to use docker, but I would like to create a docker container for ubuntu and enter it for various developments.

It was my first time to touch docker, and I saw various materials, but there were few similar cases, so as a memorandum.

flow

--Install docker --Creating a Dockerfile --Create docker image --Start docker container --Connect to docker container

install docker

Follow Official Site

$ sudo apt-get remove docker docker-engine docker.io containerd runc

$ sudo apt-get update

$ sudo apt-get install \
    apt-transport-https \
    ca-certificates \
    curl \
    gnupg-agent \
    software-properties-common

$ curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

$ sudo apt-key fingerprint 0EBFCD88

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

$ sudo apt-get update

$ sudo apt-get install docker-ce docker-ce-cli containerd.io

$ sudo docker run hello-world

With this, Hello world. At this rate, I couldn't use the docker command without adding sudo, so

$ sudo gpasswd -a <user> docker

This eliminates the need for sudo.

Creating a Dockerfile

The Dockerfile created this time is as follows.

#Specify the version of ubuntu to use
FROM ubuntu:18.04

#Install the command to use
RUN \
	apt update && \
	apt -y upgrade && \
	apt install -y build-essential && \
	apt install -y software-properties-common && \
	apt install -y curl git man unzip vim wget sudo

#Creating a user because it is inconvenient to be root
RUN useradd -m hoge
#Grant root authority
RUN gpasswd -a hoge sudo
#Password set to pass
RUN echo 'hoge:pass' | chpasswd
#Set the shell for ssh login to bash
RUN sudo sed -i 's/hoge:x:1000:1000::\/home\/hoge:\/bin\/sh/hoge:x:1000:1000::\/home\/hoge:\/bin\/bash/g' /etc/passwd

#Settings for ssh (see official website)
RUN apt install -y openssh-server
RUN mkdir /var/run/sshd
RUN sed -i 's/PermitRootLogin prohibit-password/PermitRootLogin yes/' /etc/ssh/sshd_config
# SSH login fix. Otherwise user is kicked off after login
RUN sed 's@session\s*required\s*pam_loginuid.so@session optional pam_loginuid.so@g' -i /etc/pam.d/sshd
ENV NOTVISIBLE "in users profile"
RUN echo "export VISIBLE=now" >> /etc/profile
EXPOSE 22
CMD ["/usr/sbin/sshd", "-D"]

From docker image creation to login

Create docker image

$ docker build . -t myubuntu:18.04

Execute in the directory where the Dockerfile is placed. myubuntu: 18.04 is an arbitrary name. You can check it with the following command.

$ docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
myubuntu            18.04               iiiiiidddddd        6 minutes ago       496MB

Start docker container

$ docker run -d -P --name test myubuntu:18.04

Create a container from the docker image and start it. Background execution with -d, Connect the ECPOSE port with -P to the local, Specify the container name with --name.

Ssh connection to docker container

$ docker port test 22
0.0.0.0:32768

Ssh for the port displayed in.

$ ssh hoge@localhost -p 32768
hoge@localhost's password:<pass>

Welcome to Ubuntu 18.04.4 LTS (GNU/Linux 4.15.0-47-generic x86_64)
...
hoge@nyonyonyo:~$

I was able to ssh in the container with user hoge and start bash! The rest will be developed in this (should).

reference

https://docs.docker.com/engine/examples/running_ssh_service/ https://qiita.com/techno-tanoC/items/58e9c5c74d90392d9de4