How to open multiple terminals in docker?

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

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

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.