I am following this blog on how to connect to a docker instance: https://phoenixnap.com/kb/how-to-ssh-into-docker-container. It mentions using docker attach <name>
Trying this on my ec2 instance gives us:
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
849844c1e3a5 6501862...us-east-618356524 "docker-entrypoint.s…" About a minute ago Up About a minute 0.0.0.0:32788->8401/tcp ecs-prod-clia-lab-5-Applicationprodclia-lab-8c88d2e0bc83cfb1230
Now let's try to `docker attach <instance-name>
$ docker attach ecs-prod-clia-lab-5-Applicationprodclia-lab-8c88d2e0bc83cfb1230
Error: No such container: ecs-prod-clia-lab-5-Applicationprodclia-lab-8c88d2e0bc83cfb1230
So that actually does not work? What is the correct way to do this?
To get a shell in a running container, do this:
$ docker exec -it <container-id> /bin/sh
The attach sub-command gives you access to a running containers stdout. That's not what you want here
However, if your conainer is meant to provide SSH as a service, you'll need to run it in such a way that it's exposed on the host, on some available port (like 2222).
The you'd simply "SSH in" like this:
$ ssh 127.0.0.1 -p 2222
Related
I ran a docker container on one of the terminals, on the other terminal:
$ docker container ls
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
80b6be3a7d56 rbonghi/isaac-ros-tutorial:realsense-camera "/ros_entrypoint.sh …" 9 seconds ago Up 8 seconds inspiring_almeida
and then I run
$ docker attach inspiring_almeida
now nothing seems to happen, cursor moves to a new line.
$ docker attach inspiring_almeida
What am I doing wrong? I expected to see something like root#80b6be3a7d56
P.s. I'm accessing the machine that I run docker via SSH - if that matters.
Run docker exec -it inspiring_almeida /bin/bash. It runs a shell inside the container.
attach just connects your input/output terminal with the container's input/output.
docker ps shows instances, but when I try to log in to the instance, it says it's not running?
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
eaa62ff2df11 monitor_kibana "/usr/local/bin/dumb…" 4 months ago Up 9 days kibana
613dc901f2e1 monitor_elasticsearch-search "/usr/local/bin/dock…" 4 months ago Up 9 days elasticsearch-search
$ docker exec -it eaa62 bash
Error response from daemon: Container eaa62ff2df11547744c5f7cf82cad16bf576820d2a209c4f19f173cca68f5511 is not running
$
Could it be that the container only runs for a very short time? If you use the -a flag in your statement to get only active containers, like so:
docker ps -a
Does it still show up? It could be that it runs and just uses something like ECHO. In that case, because the program run succesfully the container is immediately terminated.
Is this an official image? If so, try to run the container without the -d (for deamon) flag. This should output the run information to terminal and give you some information on what is going on.
sudo docker exec -it eaa62 bash
I am trying to access a named postgres server from inside a docker container. I can access the server via it's IP address, but not its name. I've tried --net=host and -p ServerName:5432:5432 options on the docker run command.
I will demonstrate the issue:
# on the host
$ ping ServerName
# This works
$ ping 10.1.1.25
# Works
# Then enter container with:
$ winpty docker exec -it containerName bash
$ ping 10.1.1.25
# Works
$ ping ServerName
# Does NOT work
I would guess that I need to give docker some kind of mapping from the hosts knowlegde of the network to the container. I presume that would be through the network functionality, but I can't find any instructions that I understand.
And before anyone suggests it, the postgres instance cannot be moved, including being moved into a docker container of it's own.
Output of docker ps is:
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
15c7903f7ccd imageName "tail -f /dev/null" 47 minutes ago Up 47 minutes 0.0.0.0:5432->5432/tcp, 0.0.0.0:8000->8888/tcp containerName
Solved: I needed to use the --dns option in docker run command. Then, inside the container, I needed to use the fully qualified name i.e. serverName.companyName.com instead of just serverName.
Thanks to #Dupinder Singh for pointing me to some useful DNS articles (see comments on the question).
I try to run a Shiny app on a remote server (here DigitalOcean) using Docker.
First, I created a package for my app as a .tar.gz file. Then:
Create the following Dockerfile:
FROM thinkr/rfull
COPY myapp_*.tar.gz /myapp.tar.gz
RUN R -e "install.packages('myapp.tar.gz', repos = NULL, type = 'source')"
COPY Rprofile.site /usr/local/lib/R/etc
EXPOSE 3838
CMD ["R", "-e myapp::run()"]
Create the following Rprofile.site
local({
options(shiny.port = 3838, shiny.host = "0.0.0.0")
})
Then I build the image using
docker build -t myapp .
I push the image to DockerHub using
docker tag myapp myrepo/myapp:latest
docker push myrepo/myapp
I connect to my droplet on DigitalOcean
eval $(docker-machine env mydroplet)
I create a container from my image on Dockerhub
docker run -d -p 3838:3838 myrepo/myapp
So far it seems to work fine. No message error and I got expected messages when I run docker logs mycontainer
The problem is that I do not know how to actually access the running container. When I connect to the droplet IP, I got nothing (This site can’t be reached). If use
docker inspect --format '{{ .NetworkSettings.IPAddress }}' mycontainer
I got an IP, it seems to be a local one ('172.17.0.2').
When I run docker ps here is what I got
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
6d4195XXXX myrepo/myapp "R '-e myapp::ru…" 10 days ago Up 10 days 0.0.0.0:3838->3838/tcp, 8787/tcp determined_brown
So the question is: how can I run my dockerized shiny app on my droplet IP address?
Check if you have added the firewall rule to allow connections to 3838 port.
https://www.digitalocean.com/docs/networking/firewalls/resources/troubleshooting/
First, you need to publish the port, which is what you already do.
Second, you need to access the IP address of the host machine where there port is published.
The easiest way is probably to check the output of docker-machine env mydroplet and use this IP, together with your published port.
I created the container with the following command:
docker run -d -p 52022:22 basickarl/docker-git-test
Here are the commands:
root#basickarl:~# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
root#basickarl:~# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
e4ac54468455 basickarl/docker-git-test:latest "/bin/bash" 7 minutes ago Exited (0) 26 seconds ago adoring_lumiere
22d7c5d83871 basickarl/docker-git-test:latest "/bin/bash" 2 hours ago Exited (127) About an hour ago thirsty_wright
root#basickarl:~# docker attach --sig-proxy=false e4
FATA[0000] You cannot attach to a stopped container, start it first
root#basickarl:~# docker start e4
e4
root#basickarl:~# docker attach --sig-proxy=false e4
FATA[0000] You cannot attach to a stopped container, start it first
root#basickarl:~#
Not much to say really, I'm expecting the container to start and stay upp. Here are logs:
root#basickarl:~# docker logs e4
root#basickarl:~#
You are trying to run bash, an interactive shell that requires a tty in order to operate. It doesn't really make sense to run this in "detached" mode with -d, but you can do this by adding -it to the command line, which ensures that the container has a valid tty associated with it and that stdin remains connected:
docker run -it -d -p 52022:22 basickarl/docker-git-test
You would more commonly run some sort of long-lived non-interactive process (like sshd, or a web server, or a database server, or a process manager like systemd or supervisor) when starting detached containers.
If you are trying to run a service like sshd, you cannot simply run service ssh start. This will -- depending on the distribution you're running inside your container -- do one of two things:
It will try to contact a process manager like systemd or upstart to start the service. Because there is no service manager running, this will fail.
It will actually start sshd, but it will be started in the background. This means that (a) the service sshd start command exits, which means that (b) Docker considers your container to have failed, so it cleans everything up.
If you want to run just ssh in a container, consider an example like this.
If you want to run sshd and other processes inside the container, you will need to investigate some sort of process supervisor.
What I need is to use Docker with MariaDb on different port /3301/ on my Ubuntu machine because I already had MySql installed and running on 3306.
To do this after half day searching did it using:
docker run -it -d -p 3301:3306 -v ~/mdbdata/mariaDb:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=root --name mariaDb mariadb
This pulls the image with latest MariaDb, creates container called mariaDb, and run mysql on port 3301. All data of which is located in home directory in /mdbdata/mariaDb.
To login in mysql after that can use:
mysql -u root -proot -h 127.0.0.1 -P3301
Used sources are:
The answer of Iarks in this article /using -it -d was the key :) /
how-to-install-and-use-docker-on-ubuntu-16-04
installing-and-using-mariadb-via-docker
mariadb-and-docker-use-cases-part-1
Good luck all!