How do i launch a temporary docker container?

hawksbill

Man page docker run: http://bit.ly/2h77MqO
Docker Documentation - docker run: https://docs.docker.com/engine/reference/commandline/run/

Man page for docker ps: http://bit.ly/2Ac6OAX
Docker documentation - docker ps: https://docs.docker.com/engine/reference/commandline/ps/

Man page for docker exec: http://bit.ly/2j3fIxJ
Docker documentation - docker exec: https://docs.docker.com/engine/reference/commandline/exec/

Docker can be made to run in a persistent state as well as temporary (ephemeral) state.

Run docker in ephemeral state.

$ docker run alpine /bin/sh -c "while true; do ps; sleep 2; done"
PID   USER     TIME   COMMAND
    1 root       0:00 /bin/sh -c while true; do ps; sleep 2; done
   81 root       0:00 /bin/sh
 1194 root       0:00 ps
...
...
...

You now have docker container running, to see it open an new terminal window and type:

$ docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS               NAMES
caa2d17120dc        alpine              "/bin/sh -c 'while..."   23 seconds ago      Up 22 seconds                           gallant_easley

Docker is not a full OS, but a container under the OS, but you can still get into it, like so:

-i, --interactive[=false]       Keep STDIN open even if not attached
-t, --tty[=false]               Allocate a pseudo-TTY

The container ID is obtained from the docker ps command and specify /bin/sh, to get a shell running in the container.

$ docker exec -it caa2d17120dc /bin/sh
/ # 
/ # ps
PID   USER     TIME   COMMAND
    1 root       0:00 /bin/sh -c while true; do ps; sleep 2; done
   81 root       0:00 /bin/sh
   86 root       0:00 sleep 2
   87 root       0:00 ps

You can see from the ps, your script is running, once you Ctrl-C out from the terminal running the script, then do another docker ps, the docker container is no longer running.

$ docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES

If you want to see the ones that have exited.

$ docker ps -a