Step 1:
docker ps -a
container Id: dd5cf6b519b4
I need to inspect inside the stopped docker container which is cannot start.
I tried with docker exec -it container-id bin/bash But this is for running container.
$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS NAMES
0dfd54557799 ubuntu "/bin/bash" 25 seconds ago Exited (1) 4 seconds ago peaceful_feynman
Commit the stopped image
$ docker commit 0dfd54557799 debug/ubuntu
now we have a new image
$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
debug/ubuntu <none> cc9db32dcc2d 2 seconds ago 64.3MB
create a new container from the "broken" image
$ docker run -it --rm --entrypoint sh debug/ubuntu
inside of the container we can inspect - for example, the file system
$ ls /app
App.dll
App.pdb
App.deps.json
You can start container with specific entrypoint
docker run --entrypoint sleep YOUR_IMAGE 3600
It will block current terminal for 3600 seconds. You can open new terminal tab(do not close current one) and you can verify if your container is working with the
docker ps
If you do not want to block current terminal, you can add -d flag to docker run:
docker run -d --entrypoint sleep YOUR_IMAGE 3600
Above command will start docker which will be doing nothing, then you can ssh into the container when it is working with
docker exec -ti CONTAINER HASH sh
Related
docker ps or docker container ls returns an overview of all running containers. The meaning of all columns is clear to me, except one. What does the column 'COMMAND' mean?
This is the command which is passed to the container.
$ docker run -d busybox top
$docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
3eca7c034b21 busybox "top" 6 seconds ago Up 5 seconds recursing_dirac
If you check above, top is the command which has been passed to the busybox container and that's what it's showing in the docker ps -a.
It's the command passed to docker run <image> [command].
$ docker run -d ubuntu sleep 60
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS
f0c9cd92a938 ubuntu "sleep 60" 3 seconds ago Up 1 second
If no command was specified there then it's the CMD from the Dockerfile. In ubuntu's case that would be CMD ["/bin/bash"]:
$ docker run -di ubuntu
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS
9cd752ee86f4 ubuntu "/bin/bash" 4 seconds ago Up 2 seconds
I'm trying to stop and remove a docker - container.
I started with docker turorial part1, now part2 from here: https://docs.docker.com/get-started/part2/#run-the-app
I copied souce from there. and its also available here: https://gist.github.com/sl5net/8b510bc0d3e00c474575e010003406c1
Here you could see how my console looks like:
Microsoft Windows [Version 10.0.16299.431]
C:\fre\private\docker\test18-05-14_05-27>docker build -t friendlyhello .
Sending build context to Docker daemon 5.12kB
no matching manifest for windows/amd64 in the manifest list entries
BTW solution: I swaped to linux container (right click>contextmenu on docker icon)
C:\fre\private\docker\test18-05-14_05-27>docker build -t friendlyhello .
... Successfully built itsdangerous MarkupSafe
Successfully tagged friendlyhello:latest
C:\fre\private\docker\test18-05-14_05-27>docker run -p 4000:80 friendlyhello
* Running on http://0.0.0.0:80/ (Press CTRL+C to quit)
C:\fre\private\docker\test18-05-14_05-27>docker image ls
REPOSITORY TAG IMAGE ID CREATED SIZE
friendlyhello latest 7d4d1e0f78e6 8 minutes ago 151MB
python 2.7-slim 46ba956c5967 9 days ago 140MB
C:\fre\private\docker\test18-05-14_05-27>docker container stop friendlyhello
Error response from daemon: No such container: friendlyhello
C:\fre\private\docker\test18-05-14_05-27>docker rm -f friendlyhello
Error: No such container: friendlyhello
There is no container available with the name friendlyhello as you are simply running the container using docker run -p 4000:80 friendlyhello, here friendlyhello is the name of the image, and not the container's name.
Either run that container by giving it a name like below:-
docker run -p 4000:80 --name SOMENAME friendlyhello
In this case you will be able to stop and remove that container using the below command
# container stop
docker container stop SOMENAME
# container removal
docker rm -f SOMENAME
Or if running without giving a name to the container, you will have to use the ID of the container in the commands to stop and remove, even in various other commands you will be using the ID to refer that con
The tutorial shows:
$ docker container ls
CONTAINER ID IMAGE COMMAND CREATED
1fa4ab2cf395 friendlyhello "python app.py" 28 seconds ago
You haven't added a name (tag) to your container, so you must use its ID to stop it:
docker container stop 1fa4ab2cf395
friendlyhello is the name of the image, not the container.
See docker run --name to give it a name.
If you don't have a name, you will the ID with docker ps -a
The OP adds:
using docker stop 8e008ebf3ad7 its out of list using: docker container ls buts stays in list using: docker ps -a
docker stop 8e008ebf3ad7
8e008ebf3ad7
docker container ls
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS
NAMES
5227976cb9bb friendlyhello "python app.py" About an hour ago Up About an hour 0.0.0.0:4001->80/tcp SOMENAME
docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS
PORTS NAMES
5227976cb9bb friendlyhello "python app.py" About an hour ago Up About an hour
0.0.0.0:4001->80/tcp SOMENAME
8e008ebf3ad7 friendlyhello "python app.py" 6 hours ago Exited (137) About an hour ago
That is expected: a stop will put a container in an "Exited" state, which is handy when you want to debug a container which stopped without your consent!
You can then do a docker container rm <ID> in order to reomve it from the docker ps -a list.
Note that if you had launch your container with docker run --rm ..., a stop would have stopped and removed (deleted) the container directly.
docker pull solr => to pull the docker image
docker run -p 8983:8983 -t solr => run the image and define the port
http://localhost:8983/ - run on local web browser
I'm studying the Docker documentation, but I'm having a hard time understanding the concept of creating a container, ssh, and ssh back.
I created a container with
docker run -ti ubuntu /bin/bash
Then, it starts the container and I can run commands. docker ps gives me
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
0e37da213a37 ubuntu "/bin/bash" About a minute ago Up About a minute keen_sammet
The issue is after I exit the container I can't ssh back.
I tried docker attach that gives me Error: No such container and I tried docker exec -ti <container>/bin/bash that gives me the same message Error: No such container
How do I run and ssh back to the container?
When you exit the bash process, the container exits (in general, a container will exit when the foreground process exits). The error message you are seeing is accurately describing the situation (the container is no longer running).
If you want to be able to docker exec into a container, you will want to run some sort of persistent command. For example, if you were to run:
docker run -ti -d --name mycontainer ubuntu bash
This would start a "detached" container. That means you've started bash, but it's just hanging around doing nothing. You could use docker exec to start a new process in this container:
$ docker exec -it mycontainer ps -fe
UID PID PPID C STIME TTY TIME CMD
root 1 0 0 16:28 pts/0 00:00:00 bash
root 17 0 0 16:28 pts/1 00:00:00 ps -fe
Or:
$ docker exec -it mycontainer bash
There's really no reason to start bash as the main process in this case, since you're not interacting with it. You can just as easily run...
docker run -ti -d --name mycontainer ubuntu sleep inf
...and the behavior would be the same.
The most common use case for all of this is when your docker run command starts up some sort of persistent service (like a web server, or a database server, etc), and then you use docker exec to perform diagnostic or maintenance tasks.
The docker attach command will re-connect you with the primary console of a detached container. In other words, if we return to the initial example:
docker run -ti -d --name mycontainer ubuntu bash
You could connect to that bash process (instead of starting a new one) by running:
docker attach mycontainer
At this point, exit would cause the container to exit.
First, you don't ssh to a docker container (unless you have a sshd process in that container). But you can execute a command with docker exec -ti mycontainer bash -l
But you can exec a command only on running container. If the container exited already you must use another approach : create an image from the container and run a new one.
Here is an example. First I create a container and create a file within then I exit it.
$ docker run -ti debian:9-slim bash -l
root#09f889e80153:/# echo aaaaaaaaaa > /zzz
root#09f889e80153:/# cat /zzz
aaaaaaaaaa
root#09f889e80153:/# exit
logout
As you can see the container is exited (Exited (0) 24 seconds ago)
$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
09f889e80153 debian:9-slim "bash -l" 45 seconds ago Exited (0) 24 seconds ago thirsty_hodgkin
So I create a new image with docker commit
$ docker commit 09f889e80153 bla
sha256:6ceb88470326d2da4741099c144a11a00e7eb1f86310cfa745e8d3441ac9639e
So I can run a new container that contains previous container content.
$ docker run -ti bla bash -l
root#479a0af3d197:/# cat zzz
aaaaaaaaaa
I have installed Docker and have running some Ubuntu image with command:
sudo docker run ubuntu
I would like to create some text file on it and find it next time the same image will run. How to achieve that?
UPD.
Got problems with attaching to docker.
I have running docker
docker ps -a
aef01293fdc9 ubuntu "/bin/bash" 6 hours ago Up 6 hours priceless_ramanujan
Since it is Up mode, I suppose I don't need to execute command:
docker start priceless_ramanujan
So, I run command attach
docker attach priceless_ramanujan
And got nothing in output while command not returns.
Why I can't get to container's bash?
Simple example:
$ docker run -it ubuntu
root#4d5643e8c1a8:/# echo "test" > test.txt
root#4d5643e8c1a8:/# cat test.txt
test
root#4d5643e8c1a8:/# exit
exit
$ docker run -it ubuntu
root#cdb44750bffc:/# cat test.txt
cat: test.txt: No such file or directory
root#cdb44750bffc:/#
docker run image_name
This command creates and starts a new container based on the provided image_name. If a name is not set for the container, a random one is generated and assigned by docker. In the above example 2 containers were created based on ubuntu.
with docker ps -a we can see that modest_jennings and optimistic_leakey are the random names created:
$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
cdb44750bffc ubuntu "/bin/bash" About a minute ago Exited (1) 4 seconds ago optimistic_leakey
4d5643e8c1a8 ubuntu "/bin/bash" 2 minutes ago Exited (0) 2 minutes ago modest_jennings
cat test.txt failed the 2nd time because the file didn't exist. The container started from a "clean" ubuntu image.
Actually, we created test.txt inside modest_jennings only.
docker start container_name
This command starts a stopped container. So, in our case, the file is still there:
$ docker start modest_jennings
modest_jennings
$ docker attach modest_jennings
root#4d5643e8c1a8:/# cat test.txt
test
root#4d5643e8c1a8:/#
docker commit container_name image_name
This command is to create a new image, so that you can use it later and run containers based on that image. Continuing our example...
$ docker commit modest_jennings my_ubuntu
sha256:a4357f37153ac0b94e37315595f1a3b540538283adc3721df4d4e3b39bf8334f
$ docker run -it my_ubuntu
root#2e38616d532a:/# cat test.txt
test
root#2e38616d532a:/#
If you want a custom image, you can create a Dockerfile
`FROM ubuntu:16.04
ADD ./test.txt /tmp/`
after you can build it docker build -t ubuntu:custom .
and finally run your custom image docker run --name myubuntu ubuntu:custom sleep 3000
You can check your file with docker exec -it myubuntu /bin/bash and more /tmp/test.txt
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