4.8 KiB
attach
Usage: docker attach [OPTIONS] CONTAINER
Attach to a running container
--detach-keys="<sequence>" Set up escape key sequence
--help Print usage
--no-stdin Do not attach STDIN
--sig-proxy=true Proxy all received signals to the process
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
detached process.
To stop a container, use CTRL-c. This key sequence sends SIGKILL to the
container. If --sig-proxy is true (the default),CTRL-c sends a SIGINT to
the container. You can detach from a container and leave it running using the
using CTRL-p CTRL-q key sequence.
Note: A process running as PID 1 inside a container is treated specially by Linux: it ignores any signal with the default action. So, the process will not terminate on
SIGINTorSIGTERMunless it is coded to do so.
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).
Override the detach sequence
If you want, you can configure a override the Docker key sequence for detach. This is is useful if the Docker default sequence conflicts with key squence you use for other applications. There are two ways to defines a your own detach key sequence, as a per-container override or as a configuration property on your entire configuration.
To override the sequence for an individual container, use the
--detach-keys="<sequence>" flag with the docker attach command. The format of
the <sequence> is either a letter [a-Z], or the ctrl- combined with any of
the following:
a-z(a single lowercase alpha character )@(at sign)[(left bracket)\\(two backward slashes)_(underscore)^(caret)
These a, ctrl-a, X, or ctrl-\\ values are all examples of valid key
sequences. To configure a different configuration default key sequence for all
containers, see Configuration file section.
Examples
$ docker run -d --name topdemo ubuntu /usr/bin/top -b
$ docker attach topdemo
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
top - 02:05:58 up 3:06, 0 users, load average: 0.01, 0.02, 0.05
Tasks: 1 total, 1 running, 0 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.2%us, 0.3%sy, 0.0%ni, 99.5%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 373572k total, 355780k used, 17792k free, 27880k 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
^C$
$ echo $?
0
$ docker ps -a | grep topdemo
7998ac8581f9 ubuntu:14.04 "/usr/bin/top -b" 38 seconds ago Exited (0) 21 seconds ago topdemo
And in this second example, you can see the exit code returned by the bash
process is returned by the docker attach command to its caller too:
$ docker run --name test -d -it debian
275c44472aebd77c926d4527885bb09f2f6db21d878c75f0a1c212c03d3bcfab
$ docker attach test
$$ exit 13
exit
$ echo $?
13
$ docker ps -a | grep test
275c44472aeb debian:7 "/bin/bash" 26 seconds ago Exited (13) 17 seconds ago test