docker exec and docker run do not work with names

Question

I ran docker run busybox a few times with success.

docker run busybox echo "hello from busybox"

Output:

hello from busybox

docker ps -a shows the following:

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                         PORTS               NAMES
59be6eaee13e        busybox             "echo 'hello from bu…"   2 minutes ago       Exited (0) 2 minutes ago                           lucid_ride
2d1a63cfd696        busybox             "echo 'hello from bu…"   4 minutes ago       Exited (0) 4 minutes ago                           quizzical_engelbart
69804c9b7db5        busybox             "echo 'hello from bu…"   49 minutes ago      Exited (0) 49 minutes ago                          focused_clarke
65c371540c5d        busybox             "echo 'hello from bu…"   59 minutes ago      Exited (0) 59 minutes ago                          charming_merkle
2fc6bd074048        busybox             "sh"                     About an hour ago   Exited (0) About an hour ago                       nice_noyce

Trying to use either docker run or docker exec with the name in the Names column instead of the imange name busyboxy.

docker run lucid_ride echo "hello from lucid_ride"

Output:

docker: Error response from daemon: pull access denied for lucid_ride, repository does not exist...

Using exec:

docker exec -it lucid_ride echo "hello from lucid_ride" 

Output:

Error response from daemon: Container 59be6eaee13e4089a5abcccee7fa4778f8b76332e15a0dc2f698057c0368f95f is not running

So, I can run docker run busybox all day and have instances show up in the results of the docker ps -a. But, when I try to use any of the names in the Names column (either with exec or run) it doesn't work. Why is this? Thank you.

Answer 1

Here are a short description of the docker commands above :

• docker run : starts a docker container from the given image name ;
• docker exec : runs a program inside a running container;
• docker start : restart a stopped container by relaunching the initial command;

You should definitivly try the last one ;-)