DockerCLI/docs/reference/commandline/attach.md

91 lines
3.7 KiB
Markdown
Raw Normal View History

<!--[metadata]>
+++
title = "attach"
description = "The attach command description and usage"
keywords = ["attach, running, container"]
[menu.main]
parent = "smn_cli"
+++
<![end-metadata]-->
# attach
Usage: docker attach [OPTIONS] CONTAINER
Attach to a running container
--help=false Print usage
--no-stdin=false 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.
You can detach from the container and leave it running with `CTRL-p CTRL-q`
(for a quiet exit) or with `CTRL-c` if `--sig-proxy` is false.
If `--sig-proxy` is true (the default),`CTRL-c` sends a `SIGINT` to the
container.
> **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 `SIGINT` or `SIGTERM` unless 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`).
#### 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