I have accessed a Remote Machine (call it , RM) through SSH (from my host). And I am running a docker image inside RM via my SSH session. Both are Ubuntu 16.04 based.
There are some processes running inside this docker container, so I can't exit the container.
So,how do I detach this ssh session from my host, so that those processes inside the docker would still run unaffected.
I am doing this, because I have to restart my host machine for some purpose.
PS:
In this link Correct way to detach from a container without stopping it, it's not running the docker container via SSH session. So two scenarios are different.
First, you have to start your Docker container in daemon (non-interactive) mode, using -d argument and dropping -it. Don't forget to name your container for further usage with --name foo option.
After container is started, you can control it using docker exec -it foo sh-or-whatever. If your ssh session will terminate, container will continue running. However, you docker exec session will be over.
Related
If I have ran a docker container / docker compose service without -d option, how do I change the running instance to detached mode? Is it possible?
# docker-compose up myservice &
[2] 12345
Docker supports a keyboard combination to gracefully detach from a container. Press Ctrl-P, followed by Ctrl-Q, to detach from your connection.
To change the configuration of a previously created container you can use docker update
docker update [OPTIONS] CONTAINER [CONTAINER...]
Note:
The docker update and docker container update commands are not supported for Windows containers.
I have docker on my host machine with a container running. I was wondering if it's possible, and what the best approach would be, to "trigger" a container creation from the running container.
Let's say my machine is host and I have a container called app (with id 123456789) running on host.
root#host $ docker contain ls
123456789 app_mage .... app
I would like to create a container on host from within app
root#123456789 $ docker run --name app2 ...
root#host docker container ls
123456789 app_mage .... app
12345678A app_mage .... app2
What I need is for my app to be running on docker and to run arbitrary applications in an isolated environment (but I'd rather avoid docker-in-docker)
A majority of the Docker community will veer away from these types of designs, however it is very doable.
Similar to Starting and stopping docker container from other container you can simply mount the docker.sock file from the host machine into the container, giving it privilege to access the docker daemon.
To make things more automated, you could use the docker-py sdk to start containers from inside a container, which would in turn access the Docker deamon on the host machine hosting the container that you are spawning more containers from.
For example:
docker run -v /var/run/docker.sock:/var/run/docker.sock image1 --name test1
----
import docker
def create_container():
docker.from_env().containers.run("image2", name="test2")
This example starts container test1, and runs that method inside the newly created container, which in turn creates a new container test2 running on the same host as test1.
how to access a path of a container from docker-machine? I have the ip docker-machine and I want to connect via remote in a docker image, e.g:
when I connect to ssh docker#5.5.5.5, all file are docker-machine, but I wat to conect a docker image via ssh.
whe I use this comman docker exec -u 0 -it test bash all files from the imagen are ok, but I want to access with ssh using docker-machine.
How can I do it?
This is tricky as Docker is designed to run a single process in foreground and containers dies when the process completed. This means Docker containers don't run anything additional other than what you define in the Dockerfile or docker-compose.yml.
What you can try is using docker-compose.yml file, expose the port 22 to outside world (also can be done through command line with Dockerfile). This is NOT guaranteed to work as this require the image to run an SSH daemon and most cases it runs one process.
If you're looking to persist files that are used by containers, such as when a container is re-deployed it starts where it left off, you can mount a folder from host machine to the container as a volume.
I am using docker-machine with Google Compute Engine(GCE)
to run a
docker swarm cluster. I created a swarm successfully with 2
nodes
(swnd-01 & swnd-02) in the cluster. I created a daemon container
like this
in the swarm-manager environment:
docker run -d ubuntu /bin/bash
docker ps shows the container running on swnd-01. When I tried
executing a command over the container using docker exec I get the
error that container is not running while docker ps shows otherwise.
I ssh'ed into swnd-01 via docker-machine to come to know that container
exited as soon as it was created. I tried docker run command inside the
swnd-01 but it still exits. I don't understand the behavior.
Any suggestions will be thankfully received.
The reason it exits is that the /bin/bash command completes and a Docker container only runs as long as its main process (if you run such a container with the -it flags the process will keep running while the terminal is attached).
As to why the swarm manager thought the container was still running, I'm not sure. I guess there is a short delay while Swarm updates the status of everything.
I'm running a docker containers interactively:
sudo docker run --rm -t -i CONTAINER_NAME bash
I need instances of containers to be purged after usage. Also container does not have any sense since tty is lost. When session is closed from container side (exit in bash) everything works fine but if my ssh session to host disconnects container stays running (shown in docker ps). This could also be reproduced by opening container in tmux window and then killing a window.
Is there a way to make docker to stop a container if host process (ssh session or tmux) that is attached to tty terminates?