I'm trying to find out if /opt/refresh_key.sh exists in my docker container. I've tried the likes of docker container inspect container_name and also docker run -it image_name sh but neither seem to be what I need.
Docker run launch a new container.
If you want to dive inside your existing container you should do:
docker exec -it <container-name> /bin/bash
and then you will have access to the filesystem of the existing container.
You can find container-name by doing docker ps.
Try the following :
docker exec -it <contailer-id> [[ -f "/bin/sh" ]] && echo "exists"
Place your file name in place of /bin/sh
How can do something like:
docker exec -it 06a0076fb4c0 install-smt
But use the name of the container instead
docker exec -it container/container install-smt
I am running a build on CI server so I can not manually input the container ID.
How can I achieve this?
Yes, you can do this by naming the container with --name. Note that your command with container/container is likely referencing an image name and not the container.
➜ ~ docker run --name my_nginx -p 80:80 -d nginx
d122acc37d5bc2a5e03bdb836ca7b9c69670de79063db995bfd6f66b9addfcac
➜ ~ docker exec my_nginx hostname
d122acc37d5b
Although it won't save any typing, you can do something like this if you want to use the image name instead of giving the container a name:
docker run debian
docker exec -it `docker ps -q --filter ancestor=debian` bash
This will only work if you're only running one instance of the debian image.
It does help if you're constantly amending the image when working on a new Dockerfile, and wanting to repeatedly run the same command in each new container to check your changes worked as expected.
I was able to fix this by setting a container name in the docker-compose file, and rundocker exec -it with the name form the file.
#Héctor (tnx)
These steps worked for me:
This will start the container named mytapir and spawn a shell into the docker container:
docker run -d --name mytapir -it wsmoses/tapir-built:latest bash
Upon docker ps to ensure the docker container is running:
docker exec -it mytapir /bin/bash
Will spawned a shell into an existing container named mytapir.
And you can stop the container as usual docker stop mytapir.
And starting it via docker start mytapir, if it is not running.
(check via docker ps -a)
I'm unable to connect to a container that's running on a swarm. Seems like the following doesn't work:
docker exec -it <container_ID> bash
Here is some output:
>$ docker service ls
ID NAME REPLICAS IMAGE COMMAND
4rliefwe74o5 login 1/1 login-arm64:1.0
>$ docker service ps login
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR
2jk3s2xs7ce62piunbkiptypz login.1 login-arm64:1.0 odroid64-cluster4 Running Running 5 minutes ago
Then I'll run:
$ docker exec -it 2jk3s2xs7ce62piunbkiptypz bash
or
$ docker exec -it login.1 bash
and see the following errors
Error response from daemon: No such container: 2jk3s2xs7ce62piunbkiptypz
Error response from daemon: No such container: login.1
Use docker ps to find the names you can use. Look under both CONTAINER ID and NAMES, either will work.
>$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
e53bff8bebfc login-arm64:1.0 "/bin/sh -c 'node ser" 27 seconds ago Up 25 seconds login.1.cg7fltcu3wfe7ixtnqzg8myy1
>$ docker exec -it e53bff8bebfc bash
root#e53bff8bebfc:/#
The long name is of the form $SERVICE_NAME.$REPLICA_NUMBER.$ID_FROM_SERVICE_PS
>$ docker exec -it login.1.cg7fltcu3wfe7ixtnqzg8myy1 bash
root#e53bff8bebfc:/#
Quite an older question, but just my two cents here: I very often run:
docker exec -it $(docker ps -q -f name="login*") sh
-q only returns the container id
-f name="login*" applies a filter based on container name, using a regex
This comes in handy because starting a new container will change the container name with some random characters in it. It's important that your filter returns just 1 container, so specify the name in a way that there will be just 1 result. For example: if you have a container "monster" and a container "monitor", you need -f name="moni*" to exclude the "monster" container.
The command will result in something like:docker exec -it login.1.cg7fltcu3wfe7ixtnqzg8myy1 sh
I have a docker image I'd like to poke inside. How can I pull it and get access to a shell on it? I tried sudo docker exec -it verdverm/pypge-experiments bash, but it just gave me Error response from daemon: No such container: verdverm/pypge-experiments. What am I doing wrong?
Replace exec with run:
sudo docker run -it verdverm/pypge-experiments bash
I created a container with -d so it's not interactive.
docker run -d shykes/pybuilder bin/bash
I see that the container has exited:
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
d6c45e8cc5f0 shykes/pybuilder:latest "bin/bash" 41 minutes ago Exited (0) 2 seconds ago clever_bardeen
Now I would like to run occasional commands on the machine and exit. Just to get the response.
I tried to start the machine. I tried attaching. I thought I could call run with a container, but that does not seem to be allowed. Using start just seems to run and then exist quickly.
I'd like to get back into interactive mode after exiting.
I tried:
docker attach d6c45e8cc5f0
But I get:
2014/10/01 22:33:34 You cannot attach to a stopped container, start it first
But if I start it, it exits anyway. Catch 22. I can't win.
In October 2014 the Docker team introduced docker exec command: https://docs.docker.com/engine/reference/commandline/exec/
So now you can run any command in a running container just knowing its ID (or name):
docker exec -it <container_id_or_name> echo "Hello from container!"
Note that exec command works only on already running container. If the container is currently stopped, you need to first run it with the following command:
docker run -it -d shykes/pybuilder /bin/bash
The most important thing here is the -d option, which stands for detached. It means that the command you initially provided to the container (/bin/bash) will be run in the background and the container will not stop immediately.
Your container will exit as the command you gave it will end. Use the following options to keep it live:
-i Keep STDIN open even if not attached.
-t Allocate a pseudo-TTY.
So your new run command is:
docker run -it -d shykes/pybuilder bin/bash
If you would like to attach to an already running container:
docker exec -it CONTAINER_ID /bin/bash
In these examples /bin/bash is used as the command.
So I think the answer is simpler than many misleading answers above.
To start an existing container which is stopped
docker start <container-name/ID>
To stop a running container
docker stop <container-name/ID>
Then to login to the interactive shell of a container
docker exec -it <container-name/ID> bash
To start an existing container and attach to it in one command
docker start -ai <container-name/ID>
Beware, this will stop the container on exit. But in general, you need to start the container, attach and stop it after you are done.
To expand on katrmr's answer, if the container is stopped and can't be started due to an error, you'll need to commit it to an image. Then you can launch bash in the new image:
docker commit [CONTAINER_ID] temporary_image
docker run --entrypoint=bash -it temporary_image
Some of the answers here are misleading because they concern containers that are running, not stopped.
Sven Dowideit explained on the Docker forum that containers are bound to their process (and Docker can't change the process of a stopped container, seemingly due at least to its internal structure: https://github.com/docker/docker/issues/1437). So, basically the only option is to commit the container to an image and run it with a different command.
See https://forums.docker.com/t/run-command-in-stopped-container/343
(I believe the "ENTRYPOINT with arguments" approach wouldn't work either, since you still wouldn't be able to change the arguments to a stopped container.)
I had to use bash -c to run my command:
docker exec -it CONTAINER_ID bash -c "mysql_tzinfo_to_sql /usr/share/zoneinfo | mysql mysql"
Creating a container and sending commands to it, one by one:
docker create --name=my_new_container -it ubuntu
docker start my_new_container
// ps -a says 'Up X seconds'
docker exec my_new_container /path/to/my/command
// ps -a still says 'Up X+Y seconds'
docker exec my_new_container /path/to/another/command
If you are trying to run shell script, you need run it as bash.
docker exec -it containerid bash -c /path/to/your/script.sh
This is a combined answer I made up using the CDR LDN answer above and the answer I found here.
The following example starts an Arch Linux container from an image, and then installs git on that container using the pacman tool:
sudo docker run -it -d archlinux /bin/bash
sudo docker ps -l
sudo docker exec -it [container_ID] script /dev/null -c "pacman -S git --noconfirm"
That is all.
Pipe a command to docker exec bash stdin
Must remove the -t for it to work:
echo 'touch myfile' | docker exec -i CONTAINER_NAME bash
This can be more convenient that using CLI options sometimes.
Tested with:
docker run --name ub16 -it ubuntu:16.04 bash
then on another shell:
echo 'touch myfile' | docker exec -i ub16 bash
Then on first shell:
ls -l myfile
Tested on Docker 1.13.1, Ubuntu 16.04 host.
I would like to note that the top answer is a little misleading.
The issue with executing docker run is that a new container is created every time. However, there are cases where we would like to revisit old containers or not take up space with new containers.
(Given clever_bardeen is the name of the container created...)
In OP's case, make sure the docker image is first running by executing the following command:
docker start clever_bardeen
Then, execute the docker container using the following command:
docker exec -it clever_bardeen /bin/bash
I usually use this:
docker exec -it my-container-name bash
to continuously interact with a running container.
Assuming the image is using the default entrypoint /bin/sh -c, running /bin/bash will exit immediately in daemon mode (-d). If you want this container to run an interactive shell, use -it instead of -d. If you want to execute arbitrary commands in a container usually executing another process, you might want to try nsenter or nsinit. Have a look at https://blog.codecentric.de/en/2014/07/enter-docker-container/ for the details.
Unfortunately it is impossible to override ENTRYPOINT with arguments with docker run --entrypoint to achieve this goal.
Note: you can override the ENTRYPOINT setting using --entrypoint, but
this can only set the binary to exec (no sh -c will be used).
For Mac:
$ docker exec -it <container-name> sh
if you want to connect as root user:
$ docker exec -u 0 -it <container-name> sh
Simple answer: start and attach at the same time. In this case you are doing exactly what you asked for.
docker start <CONTAINER_ID/CONTAINER_NAME> && docker attach <CONTAINER_ID/CONTAINER_NAME>
make sure to change <CONTAINER_ID/CONTAINER_NAME>
I am running windows container and I need to look inside the docker container for files and folder created and copied.
In order to do that I used following docker entrypoint command to get the command prompt running inside the container or attach to the container.
ENTRYPOINT ["C:\\Windows\\System32\\cmd.exe", "-D", "FOREGROUND"]
That helped me both to the command prompt attach to container and to keep the container a live. :)
# docker exec -d container_id command
Ex:
# docker exec -d xcdefrdtt service jira stop
A quick way to resume and access the most recently exited container:
docker start -a -i `docker ps -q -l`
An easy solution that solved a similar problem for me:
docker run --interactive --tty <name_of_image>