As described in docker attach in docker CLI reference page, docker attach attaches your terminal’s standard input, output, and error (or any combination of the three) to a running container using the container’s ID or name. This allows you to view its ongoing output or to control it interactively, as though the commands were running directly in your terminal.
docker attach [OPTIONS] CONTAINER
Here is example:
# Check running docker containers
$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
250510ca2534 azure-vote-front "/entrypoint.sh /sta…" 2 weeks ago Up 2 minutes 443/tcp, 0.0.0.0:8080->80/tcp azure-vote-front
f01f4cbbbae3 azure-vote-back "docker-entrypoint.s…" 2 weeks ago Up 4 minutes 0.0.0.0:3306->3306/tcp azure-vote-back
# attache to azure-vote-front
$ docker attach azure-vote-front
# send request to service run by azure-vote-front
$ curl localhost:8080
# Then, you'll see the container's output like this:
172.18.0.1 - - [19/Nov/2018:00:59:11 +0000] "GET / HTTP/1.1" 200 967 "-" "curl/7.54.0" "-"
[pid: 16|app: 0|req: 2/2] 172.18.0.1 () {32 vars in 334 bytes} [Mon Nov 19 00:59:11 2018] GET / => generated 967 bytes in 7 msecs (HTTP/1.1 200) 2 headers in 80 bytes (1 switches on core 0)As described in docker exec,
docker exec command runs a new command in a running container. The command started using docker exec only runs while the container’s primary process (PID 1) is running, and it is not restarted if the container is restarted.
docker exec [OPTIONS] CONTAINER COMMAND [ARG...]
Here is an example
# Check running docker containers
$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
250510ca2534 azure-vote-front "/entrypoint.sh /sta…" 2 weeks ago Up 2 minutes 443/tcp, 0.0.0.0:8080->80/tcp azure-vote-front
f01f4cbbbae3 azure-vote-back "docker-entrypoint.s…" 2 weeks ago Up 4 minutes 0.0.0.0:3306->3306/tcp azure-vote-back
# exec /bin/bash in running a azure-vote-front container
$ docker exec -it azure-vote-front /bin/bash
root@250510ca2534:/app# ls
__pycache__ config_file.cfg main.py prestart.sh static templates uwsgi.ini
root@250510ca2534:/app# ps aux
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 0.0 0.9 49944 20296 ? Ss 00:54 0:00 /usr/bin/python /usr/bin/supervisord
root 11 0.0 0.2 32608 4984 ? S 00:54 0:00 nginx: master process /usr/sbin/nginx
root 12 0.0 1.5 174740 31932 ? S 00:54 0:00 /usr/local/bin/uwsgi --ini /etc/uwsgi/uwsgi.ini --die-on-term --need-app
nginx 13 0.0 0.1 33072 3328 ? S 00:54 0:00 nginx: worker process
root 15 0.0 1.0 174740 21712 ? S 00:54 0:00 /usr/local/bin/uwsgi --ini /etc/uwsgi/uwsgi.ini --die-on-term --need-app
root 16 0.0 1.2 179612 25980 ? S 00:54 0:00 /usr/local/bin/uwsgi --ini /etc/uwsgi/uwsgi.ini --die-on-term --need-app
root 17 0.0 0.1 19956 3556 pts/0 Ss 01:02 0:00 /bin/bash
root 30 0.0 0.1 38384 3128 pts/0 R+ 01:06 0:00 ps auxIn your Dockerfile, you can use the verb EXPOSE to expose multiple ports.
EXPOSE 3000 80 443 22
Then, you would like to build an new image based on above Dockerfile.
$ docker build -t foo:tag .Then, you can use the -p to map host port with the container port, as defined in above EXPOSE of Dockerfile.
docker run -p 3001:3000 -p 23:22
In case you would like to expose a range of continuous ports, you can run docker like this:
docker run -it -p 7100-7120:7100-7120/tcp