Start sshd automatically with docker container

Question

Given:

• container based on ubuntu:13.10
• installed ssh (via apt-get install ssh)

Problem: each when I start container I have to run sshd manually service ssh start

Tried: update-rc.d ssh defaults, but it does not helps.

Question: how to setup container to start sshd service automatically during container start?

Answer 1

Here is a Dockerfile which installs ssh server and runs it:

# Build Ubuntu image with base functionality. FROM ubuntu:focal AS ubuntu-base ENV DEBIAN_FRONTEND noninteractive SHELL ["/bin/bash", "-o", "pipefail", "-c"]  # Setup the default user. RUN useradd -rm -d /home/ubuntu -s /bin/bash -g root -G sudo ubuntu RUN echo 'ubuntu:ubuntu' | chpasswd USER ubuntu WORKDIR /home/ubuntu  # Build image with Python and SSHD. FROM ubuntu-base AS ubuntu-with-sshd USER root  # Install required tools. RUN apt-get -qq update \     && apt-get -qq --no-install-recommends install vim-tiny=2:8.1.* \     && apt-get -qq --no-install-recommends install sudo=1.8.* \     && apt-get -qq --no-install-recommends install python3-pip=20.0.* \     && apt-get -qq --no-install-recommends install openssh-server=1:8.* \     && apt-get -qq clean    \     && rm -rf /var/lib/apt/lists/*  # Configure SSHD. # 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 RUN mkdir /var/run/sshd RUN bash -c 'install -m755 <(printf "#!/bin/sh\nexit 0") /usr/sbin/policy-rc.d' RUN ex +'%s/^#\zeListenAddress/\1/g' -scwq /etc/ssh/sshd_config RUN ex +'%s/^#\zeHostKey .*ssh_host_.*_key/\1/g' -scwq /etc/ssh/sshd_config RUN RUNLEVEL=1 dpkg-reconfigure openssh-server RUN ssh-keygen -A -v RUN update-rc.d ssh defaults  # Configure sudo. RUN ex +"%s/^%sudo.*$/%sudo ALL=(ALL:ALL) NOPASSWD:ALL/g" -scwq! /etc/sudoers  # Generate and configure user keys. USER ubuntu RUN ssh-keygen -t ed25519 -f ~/.ssh/id_ed25519 #COPY --chown=ubuntu:root "./files/authorized_keys" /home/ubuntu/.ssh/authorized_keys  # Setup default command and/or parameters. EXPOSE 22 CMD ["/usr/bin/sudo", "/usr/sbin/sshd", "-D", "-o", "ListenAddress=0.0.0.0"] 

Build with the following command:

docker build --target ubuntu-with-sshd -t ubuntu-with-sshd . 

Then run with:

docker run -p 2222:22 ubuntu-with-sshd 

To connect to container via local port, run: ssh -v localhost -p 2222.

To check for container IP address, use docker ps and docker inspect.

---

Here is example of docker-compose.yml file:

--- version: '3.4' services:   ubuntu-with-sshd:     image: "ubuntu-with-sshd:latest"     build:       context: "."       target: "ubuntu-with-sshd"     networks:       mynet:         ipv4_address: 172.16.128.2     ports:       - "2222:22"     privileged: true # Required for /usr/sbin/init networks:   mynet:     ipam:       config:         - subnet: 172.16.128.0/24 

To run, type:

docker-compose up --build 

Answer 2

Just try:

ENTRYPOINT service ssh restart && bash 

in your dockerfile, it works fun for me!

more details here: How to automatically start a service when running a docker container?