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How to ping/ssh to a running docker by name?

Time:11-22

I want to access a running docker via ssh, by name.

  1. How can I ping to the docker?
  2. How can I connect to the docker using ssh?
  3. Bonus: How can I connect to the docker, using ssh, from a different computer than the one it runs on?

I am aware that it is considered better to access via docker exec, but this does not work for me, as I have to use ssh for my case [I am trying to use clion's fully remote mode on a remote hosted docker via ssh tunneling. Their docs only support remote non-docker, or local docker].

This is my dockerfile

ARG VER=
ARG TOOL_DOCKER=
ARG BASE_IMAGE=
ARG TOOL_DIR=
FROM devsrv:5000/${TOOL_DOCKER}:${VER} AS tool_base

ARG VER=
ARG BASE_IMAGE=
ARG TOOL_DIR=
FROM ${BASE_IMAGE}
ARG VER=
ARG BASE_IMAGE=
ARG TOOL_DOCKER=
ARG TOOL_DIR=
ARG UNAME=
ARG UID=
USER root

COPY launchpad.key /tmp/launchpad.key

RUN apt-get update && \
    apt-get install -y software-properties-common && \
    apt-key add /tmp/launchpad.key && \
    add-apt-repository -y ppa:git-core/ppa && apt-get update && \
    apt-get install -y git libxt-dev libxtst6 libnss3 libnspr4 \
        libgbm-dev libxss-dev libasound2 libatk-bridge2.0-0 \
        libcanberra-gtk-module libcanberra-gtk3-module valgrind sudo \
        libx11-xcb-dev && \
    apt-get clean && \
    rm -rf /var/lib/apt/lists/* && \
    rm -rf /tmp/*

RUN groupadd --system ${UNAME} --gid ${UID} && \
    useradd --uid ${UID} --system --gid ${UNAME} --home-dir /home/${UNAME} --create-home --comment "Docker image user" ${UNAME} && \
    chown -R ${UNAME}:${UNAME} /home/${UNAME} && \
    usermod -aG sudo ${UNAME} && \
    echo "${UNAME}  ALL=(ALL) NOPASSWD:ALL" | sudo tee /etc/sudoers.d/${UNAME}

COPY --from=tool_base ${TOOL_DIR} ${TOOL_DIR}

and this is the gist of how it is run

BUILD_CMDLINE="docker build \
    --build-arg UID=${UID} \
    --build-arg UNAME=${USER} \
    --build-arg VER=${VERSION} \
    --build-arg BASE_IMAGE=${BASE_DOCKER} \
    --build-arg TOOL_DOCKER=$(${DIR}/impl/known-tools.py docker ${TOOL}) \
    --build-arg TOOL_DIR=$(${DIR}/impl/known-tools.py tool-dir ${TOOL}) \
    -f ${DIR}/impl/personal-tool.dockerfile -t ${IMAGE} ${DIR}/impl"

echo "Building docker using: ${BUILD_CMDLINE}"
${BUILD_CMDLINE} || exit 1

# Need to give the container access to your windowing system
xhost  
echo $HOME
echo ${USER_ID}:${GROUP_ID}
RUN_CMD="docker run --group-add ${DOCKER_GROUP_ID} \
                --env HOME=${HOME} \
                --env="DISPLAY" \
                --entrypoint /bin/bash \
                --interactive \
                --net "host" \
                --rm \
                --tty \
                --user=${USER_ID}:${GROUP_ID} \
                --volume ${HOME}:${HOME} \
                --volume /isilon:/isilon \
                --volume /mnt:/mnt \
                $(cat ${HOME}/personal-uv-docker-flags) \
                -v "${HOME}/.Xauthority:${HOME}/.Xauthority:rw" \
                --volume /var/run/docker.sock:/var/run/docker.sock \
                --workdir ${HOME} \
                --cap-add sys_ptrace \
                -p127.0.0.1:2222:22 \
                --name my_docker \
                ${IMAGE} $(${DIR}/impl/known-tools.py cmd-line ${TOOL})"

echo "Running docker using: ${RUN_CMD}"

${RUN_CMD}

When running this docker, doing docker ps gives

CONTAINER ID        IMAGE                                                        COMMAND                  CREATED             STATUS              PORTS               NAMES
a5f15b6f5e7b        clion-professional_devsrv_5000/acq-base-docker_latest:noam   "/bin/bash /opt/clio…"   18 minutes ago      Up 18 minutes                           my_docker


If information is missing please say so and I will edit the question.


Edit:

Edited the dockerfile to


COPY launchpad.key /tmp/launchpad.key

RUN apt-get update && \
    apt-get install -y software-properties-common && \
    apt-get install -y openssh-client && \
    apt-get install -y openssh-server && \
    systemctl enable sshd && \
    apt-key add /tmp/launchpad.key && \
    add-apt-repository -y ppa:git-core/ppa && apt-get update && \
    apt-get install -y git libxt-dev libxtst6 libnss3 libnspr4 \
        libgbm-dev libxss-dev libasound2 libatk-bridge2.0-0 \
        libcanberra-gtk-module libcanberra-gtk3-module valgrind sudo \
        libx11-xcb-dev && \
    apt-get clean && \
    rm -rf /var/lib/apt/lists/* && \
    rm -rf /tmp/*

RUN groupadd --system ${UNAME} --gid ${UID} && \
    useradd --uid ${UID} --system --gid ${UNAME} --home-dir /home/${UNAME} --create-home --comment "Docker image user" ${UNAME} && \
    chown -R ${UNAME}:${UNAME} /home/${UNAME} && \
    usermod -aG sudo ${UNAME} && \
    echo "${UNAME}  ALL=(ALL) NOPASSWD:ALL" | sudo tee /etc/sudoers.d/${UNAME}

COPY --from=tool_base ${TOOL_DIR} ${TOOL_DIR}

USER {UNAME}

output:

...

Get:11 http://archive.ubuntu.com/ubuntu xenial/main amd64 ssh-import-id all 5.5-0ubuntu1 [10.2 kB]
debconf: delaying package configuration, since apt-utils is not installed
Fetched 1003 kB in 0s (1184 kB/s)
Selecting previously unselected package libwrap0:amd64.
(Reading database ... 25945 files and directories currently installed.)
Preparing to unpack .../libwrap0_7.6.q-25_amd64.deb ...
Unpacking libwrap0:amd64 (7.6.q-25) ...
Selecting previously unselected package ncurses-term.
Preparing to unpack .../ncurses-term_6.0 20160213-1ubuntu1_all.deb ...
Unpacking ncurses-term (6.0 20160213-1ubuntu1) ...
Selecting previously unselected package openssh-sftp-server.
Preparing to unpack .../openssh-sftp-server_1:7.2p2-4ubuntu2.10_amd64.deb ...
Unpacking openssh-sftp-server (1:7.2p2-4ubuntu2.10) ...
Selecting previously unselected package openssh-server.
Preparing to unpack .../openssh-server_1:7.2p2-4ubuntu2.10_amd64.deb ...
Unpacking openssh-server (1:7.2p2-4ubuntu2.10) ...
Selecting previously unselected package python3-pkg-resources.
Preparing to unpack .../python3-pkg-resources_20.7.0-1_all.deb ...
Unpacking python3-pkg-resources (20.7.0-1) ...
Selecting previously unselected package python3-chardet.
Preparing to unpack .../python3-chardet_2.3.0-2_all.deb ...
Unpacking python3-chardet (2.3.0-2) ...
Selecting previously unselected package python3-six.
Preparing to unpack .../python3-six_1.10.0-3_all.deb ...
Unpacking python3-six (1.10.0-3) ...
Selecting previously unselected package python3-urllib3.
Preparing to unpack .../python3-urllib3_1.13.1-2ubuntu0.16.04.4_all.deb ...
Unpacking python3-urllib3 (1.13.1-2ubuntu0.16.04.4) ...
Selecting previously unselected package python3-requests.
Preparing to unpack .../python3-requests_2.9.1-3ubuntu0.1_all.deb ...
Unpacking python3-requests (2.9.1-3ubuntu0.1) ...
Selecting previously unselected package tcpd.
Preparing to unpack .../tcpd_7.6.q-25_amd64.deb ...
Unpacking tcpd (7.6.q-25) ...
Selecting previously unselected package ssh-import-id.
Preparing to unpack .../ssh-import-id_5.5-0ubuntu1_all.deb ...
Unpacking ssh-import-id (5.5-0ubuntu1) ...
Processing triggers for man-db (2.7.5-1) ...
Processing triggers for systemd (229-4ubuntu21.16) ...
Setting up libwrap0:amd64 (7.6.q-25) ...
Setting up ncurses-term (6.0 20160213-1ubuntu1) ...
Setting up openssh-sftp-server (1:7.2p2-4ubuntu2.10) ...
Setting up openssh-server (1:7.2p2-4ubuntu2.10) ...
debconf: unable to initialize frontend: Dialog
debconf: (TERM is not set, so the dialog frontend is not usable.)
debconf: falling back to frontend: Readline
Creating SSH2 RSA key; this may take some time ...
2048 SHA256:Wlq9V siHa4herOkUxo f7Gsy Dr5obNzd21YlvcTxw root@20cd14a69430 (RSA)
Creating SSH2 DSA key; this may take some time ...
1024 SHA256:PHYTyaGyXHO7N5V3VOGoFcBY23FDBydEcCdrrI01ZpU root@20cd14a69430 (DSA)
Creating SSH2 ECDSA key; this may take some time ...
256 SHA256:/T4agN5tch9KKW3 vp7jdFhGBGHtZ2lA7rD9BFk/vfM root@20cd14a69430 (ECDSA)
Creating SSH2 ED25519 key; this may take some time ...
256 SHA256:xm6KylI0biBsq1imRWYuTecinrwTAlFE ekVlWV8G3o root@20cd14a69430 (ED25519)
invoke-rc.d: could not determine current runlevel
invoke-rc.d: policy-rc.d denied execution of start.
Setting up python3-pkg-resources (20.7.0-1) ...
Setting up python3-chardet (2.3.0-2) ...
Setting up python3-six (1.10.0-3) ...
Setting up python3-urllib3 (1.13.1-2ubuntu0.16.04.4) ...
Setting up python3-requests (2.9.1-3ubuntu0.1) ...
Setting up tcpd (7.6.q-25) ...
Setting up ssh-import-id (5.5-0ubuntu1) ...
Processing triggers for libc-bin (2.23-0ubuntu11) ...
Processing triggers for systemd (229-4ubuntu21.16) ...
Operation failed: Too many levels of symbolic links
The command '/bin/sh -c apt-get update &&     apt-get install -y software-properties-common &&     apt-get install -y openssh-client &&     apt-get install -y openssh-server &&     systemctl enable sshd &&     apt-key add /tmp/launchpad.key &&     add-apt-repository -y ppa:git-core/ppa && apt-get update &&     apt-get install -y git libxt-dev libxtst6 libnss3 libnspr4         libgbm-dev libxss-dev libasound2 libatk-bridge2.0-0         libcanberra-gtk-module libcanberra-gtk3-module valgrind sudo         libx11-xcb-dev &&     apt-get clean &&     rm -rf /var/lib/apt/lists/* &&     rm -rf /tmp/*' returned a non-zero code: 1

With the highlighted errors being

invoke-rc.d: could not determine current runlevel
invoke-rc.d: policy-rc.d denied execution of start.

and

Operation failed: Too many levels of symbolic links

CodePudding user response:

I think docker does not support connecting to the container by name, you have to expose the port to the host machine and then connect through it.

Or if you still want to connect via name you can refer here defreitas/dns-proxy-server

Example:

# First run DPS
$ docker run --rm --hostname dns.mageddo \
-v /var/run/docker.sock:/var/run/docker.sock \
-v /etc/resolv.conf:/etc/resolv.conf \
defreitas/dns-proxy-server

# Then run the container
$ docker run --hostname my_docker --name my_docker -d my_image

# Now, you can connect by name
$ ping my_docker

CodePudding user response:

Based on @vector's answer, here is a complete solution :

#!/bin/bash
# docker.sh

docker run --rm --hostname dns.mageddo\
    -v /var/run/docker.sock:/var/run/docker.sock\
    -v /etc/resolv.conf:/etc/resolv.conf\
    -d defreitas/dns-proxy-server

docker run -ti --hostname my_docker --name my_docker\
    -p 2222:22 --rm debian bash -c "
        apt update -y;apt install -y openssh-server; service ssh start;
        useradd pi; mkdir -p /home/pi; chown pi /home/pi;
        passwd pi <<< \$'password\npassword'; exec bash"

In one terminal, run ./docker.sh, once both containers running,

open another terminal :

  1. ping my_docker

  2. ssh pi@my_docker # password : password

  3. from another computer than your-machine :

    ssh -p 2222 pi@your-machine # password : password

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