% DOCKER(1) Docker User Manuals % Docker Community % JUNE 2014
docker-attach - Attach to a running container
docker attach [--help]/ [--no-stdin[=false]] [--sig-proxy[=true]] CONTAINER
The docker attach command allows you to attach to a running container using the container's ID or name, either to view its ongoing output or to control it interactively. You can attach to the same contained process multiple times simultaneously, screen sharing style, or quickly view the progress of your daemonized process.
You can detach from the container (and leave it running) with CTRL-p CTRL-q (for a quiet exit) or CTRL-c which will send a SIGKILL to the container. When you are attached to a container, and exit its main process, the process's exit code will be returned to the client.
It is forbidden to redirect the standard input of a docker attach command while attaching to a tty-enabled container (i.e.: launched with -t).
--help Print usage statement
--no-stdin=true|false Do not attach STDIN. The default is false.
--sig-proxy=true|false Proxy all received signals to the process (non-TTY mode only). SIGCHLD, SIGKILL, and SIGSTOP are not proxied. The default is true.
In this example the top command is run inside a container, from an image called fedora, in detached mode. The ID from the container is passed into the docker attach command:
# ID=$(sudo docker run -d fedora /usr/bin/top -b) # sudo docker attach $ID top - 02:05:52 up 3:05, 0 users, load average: 0.01, 0.02, 0.05 Tasks: 1 total, 1 running, 0 sleeping, 0 stopped, 0 zombie Cpu(s): 0.1%us, 0.2%sy, 0.0%ni, 99.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 373572k total, 355560k used, 18012k free, 27872k buffers Swap: 786428k total, 0k used, 786428k free, 221740k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1 root 20 0 17200 1116 912 R 0 0.3 0:00.03 top top - 02:05:55 up 3:05, 0 users, load average: 0.01, 0.02, 0.05 Tasks: 1 total, 1 running, 0 sleeping, 0 stopped, 0 zombie Cpu(s): 0.0%us, 0.2%sy, 0.0%ni, 99.8%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 373572k total, 355244k used, 18328k free, 27872k buffers Swap: 786428k total, 0k used, 786428k free, 221776k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1 root 20 0 17208 1144 932 R 0 0.3 0:00.03 top
April 2014, Originally compiled by William Henry (whenry at redhat dot com) based on docker.com source material and internal work. June 2014, updated by Sven Dowideit SvenDowideit@home.org.au