How to open multiple terminals in docker?

Question

I need to launch two distinct processes on a docker container which requires two terminals.What is the best way to achieve this?

Answer 1

You can run docker exec -it <container> bash from multiple terminals to launch several sessions connected to the same container.

Answer 2

To expand on @eltonStoneman's great answer (For all those new docker folks like me):

1. Open a docker terminal

2. Get the image running as a container in the background: docker run -d -it <image_id>

• Tip: docker ps will show the container_id that you just fired up from said image.

3. Per @eltonStoneman's advice: docker exec -it <container_id> bash

• Now your docker terminal is showing an interactive terminal to the container.

4. Open up another terminal and perform step 3 to create another interactive terminal to the container. (Rinse and Repeat)

Answer 3

docker run -it container_name bash starts a new container with bash promt.

docker exec -it container_name bash joins already running container's bash prompt.

Answer 4

First get the name of the container docker container ls Then get run docker exec command to get in that container docker exec <container_id> bash

Answer 5

Using Docker Compose: Let's say you have a Compose yml that enables X-Windows.

You can follow the steps below to launch terminals for a graphic IDE (e.g. qtCreator), nautilus and a terminal window.

Assumptions:

• Host is Windows 10. 1803
• Image is Ubuntu Xenial
• Docker engine is 18.03.1-ce
• Docker Compose is 1.21.1
• Windows Xming X Server is 7.7.0.25 - using IPv4 interface 192.168.1.101

Dockerfile: Dockerfile-dev-ubuntu_xenial - creates the Docker image

FROM ubuntu:xenial
ARG DEBIAN_FRONTEND=noninteractive
LABEL maintainer "Your NAME <your.address@yourmailhost.com>"
RUN apt-get update ; apt-get install -y apt-utils desktop-file-utils dialog nautilus build-essential debhelper fakeroot ccache lsb-release
RUN apt-get install -y autotools-dev autoconf pkg-config libtool curl gedit git wget unzip lintian
RUN apt-get install -y qtcreator valgrind
RUN apt-get install -y sudo \
    && groupadd -r user -g 1000 \
    && useradd -u 1000 -r -g user -m -d /user -s /sbin/nologin -c "Build pkg user" user \
    && chmod 755 /user \
    && echo "user ALL=(root) NOPASSWD:ALL" > /etc/sudoers.d/user \
    && chmod 0440 /etc/sudoers.d/user
WORKDIR /user
USER user
VOLUME ["/buildpkg", "/user/projects", "/user/resources"]
CMD /bin/bash

Compose.yml: compose-dev-linux.yml

version: '3'
services:
  # Commands:
  #   Build: docker-compose -f compose-dev-linux.yml build dev_ubuntu_xenial
  #   Up   : docker-compose -f compose-dev-linux.yml up -d dev_ubuntu_xenial
  #   Run  : docker-compose -f compose-dev-linux.yml run dev_ubuntu_xenial
  #   Down : docker-compose -f compose-dev-linux.yml down
  # Host folders:
  #   %USERPROFILE%/Projects
  #   %USERPROFILE%/Projects/Docker-builds
  #   %USERPROFILE%/Projects/Docker-resources
  # Docker configuration file locations:
  #   %USERPROFILE%/Dockerfiles/Dockerfile-dev-ubuntu_xenial
  #   %USERPROFILE%/compose-dev-linux.yml
  dev_ubuntu_xenial:
    security_opt:
      - seccomp:unconfined
    cap_add:
      - SYS_ADMIN
    environment:
      - DISPLAY=192.168.1.101:0
    network_mode: host
    image: "application-dev-platform/application:ubuntu_xenial"
    container_name: application-dev-ubuntu_xenial
    command: bash -c "/bin/bash"
    tty: true
    build:
      context: ./Dockerfiles
      dockerfile: Dockerfile-dev-ubuntu_xenial
    volumes:
      - ./Projects:/user/projects
      - ./Projects/Docker-builds:/buildpkg
      - ./Projects/Docker-resources:/user/resources

Run: - initial Powershell terminal

1. Build image: docker-compose -f compose-dev-linux.yml build dev_ubuntu_xenial
2. Launch Docker detached: docker-compose -f compose-dev-linux.yml up -d dev_ubuntu_xenial
3. List container(s): docker ps
4. Launch container: docker exec -it <CONTAINER ID> bash
5. Launch qtCreator: user@linuxkit-<generatedid>:~$ qtcreator

Run: - new Powershell terminal

1. Launch container: docker exec -it <CONTAINER ID> bash
2. Launch nautilus: nautilus

Run: - new Powershell terminal

1. Launch container: docker exec -it <CONTAINER ID> bash
2. Launch terminal: user@linuxkit-<generatedid>:~$

Answer 6

first of all I entered below command:

docker exec -it <containerName> bash

but docker said this container doesn't exist... after that I replaced containerName with containerID and this trick worked for me;

if you want to know each containers id run below command:

sudo docker ps

after that run this command to open new terminal to your container:

docker exec -it <containerID> bash

cheers!

Answer 7

_{I started a container in a terminal (-i interactive, -t TTY):}

docker run -i -t <IMAGE_URL> /bin/bash

_{My command prompt now starts with root@484ded1212aa:/ in which 484ded1212aa is the CONTAINER ID. In another tab (or window) I used that ID:}

docker exec -i -t 484ded1212aa /bin/bash

_{Now both terminal tabs start with root@484ded1212aa:/ and the second one contains the Git repo that I had cloned in the first terminal (between the above two commands). This was useful because I wanted to interactively change the code in one tab, and run it in another.}

_{Another way to get the CONTAINER_ID or NAMES is by the command:}

docker container ls

_{which gives me:}

CONTAINER ID        IMAGE                                            COMMAND             CREATED             STATUS              PORTS               NAMES
484ded1212aa        registry.gitlab.com/molcas/dockerfiles/gcc-4.8   "/bin/bash"         2 hours ago         Up 2 hours                              hardcore_einstein

^{Notice that there's still only one container, even though it's open in two tabs.}

Answer 8

If you are able to run Kitematic - you can click on exec button to open terminal in selected container.