I'm receiving an error from docker when I run my docker file. It's saying the /var/lib/docker/aufs/layers/xxxx: no such file or directory when I run Docker build .
I have tried numerous ways to remove containers and images so I'm pretty much stock on this one.
Any
The Docker file is:
FROM node:6
RUN git clone https://github.com/preboot/angular2-webpack.git
WORKDIR angular2-webpack
RUN sed -i.bak 's/--port 8080/--host 0.0.0.0 --port 8080/'
package.json RUN npm i
CMD [ "npm", "run", "start" ]
The complete console output is:
Sending build context to Docker daemon
9.728 kB
Step 1 : FROM node:6
6: Pulling from library/node
6a5a5368e0c2: Already exists
7b9457ec39de: Already exists
ff18e19c2db4: Already exists
6a3d69edbe90: Already exists
0ce4b037e17f: Already exists
82252a100d5a: Already exists
Digest:
sha256:db245bde5445eb122d8dc090ba98539a9ef7f56c0ea981ade643695af0d8eaf0
Status: Downloaded newer image for node:6
---> 9873603dc506 Step 2 :
RUN git clone https://github.com/preboot/angular2-webpack.git open
/var/lib/docker/aufs/layers/9319fd93cb6d6718243ff2e65ce5d2aa6122a1bb9211aa9f8e88d85c298727e5:
no such file or directory User:docker-test
Edit
The issue was resolved thanks to #BMitchs' recommendation:
rm -rf /var/lib/docker/*
Uninstall Docker completely
re install docker
With that sort of corruption, I'd give a full docker wipe a try, rm -rf /var/lib/docker/*. Before doing that, backup any data (volumes), then shutdown docker, and you'll need to pull or rebuild all your images again. If there are still problems with aufs, try changing the filesystem driver, e.g. changing to dockerd -s overlay2 in your service startup.
It doesn't hurt to check for common issues, like running out of disk space or old version of the application, first.
try building the image again on a clean machine or using the --no-cache flag, this seems like a caching issue.
Also - In my company, we clone the code into the machine building the image, and then copy the code into the container. In my opinion - it's a better solution, but I think it's a matter of taste.
The data files used by Docker are corrupted. You can execute the following command:
1- If they exist, delete contain and image
docker rm CONTAINER ID
docker rmi IMAGE ID
2- Stop the Docker service (Ubuntu)
service docker stop
3- Start the Docker service (Ubuntu)
service docker start
4- Check Docker service status (Ubuntu)
service docker status
docker system prune -af
worked for me
Many organizations are using Docker specifically for the advantage of being able to seamlessly roll back deployed software. For instance, given an image called newapi, deployment looks like this:
# fetch latest
docker pull newapi:latest
# stop old one and terminate it
docker stop -t 10 newapi-container
docker rm -f newapi-container
# start new one
docker run ... newapi:latest
If something goes wrong, we can revert back to the previous version like this:
docker stop -t 10 newapi-container
docker rm -f newapi-container
docker run ... newapi:0.9.2
The problem becomes that over time, our local Docker images index will get huge. Does Docker automatically get rid of old, unused images from its local index to save disk space, or do I have to manually manage these?
It doesn't do it for you but you can use the following commands to do it manually.
#!/bin/bash
# Delete all containers
sudo docker rm $(sudo docker ps -a -q)
# Delete all images
sudo docker rmi $(sudo docker images -q)
The documentation relating to the docker rm and rmi commands is here: https://docs.docker.com/reference/commandline/cli/#rm
The additional commands are standard bash.
Update Sept. 2016 for docker upcoming docker 1.13: PR 26108 and commit 86de7c0 introduce a few new commands to help facilitate visualizing how much space the docker daemon data is taking on disk and allowing for easily cleaning up "unneeded" excess.
docker system prune will delete ALL dangling data (i.e. In order: containers stopped, volumes without containers and images with no containers). Even unused data, with -a option.
You also have:
docker container prune
docker image prune
docker network prune
docker volume prune
Taken from here.
I want to mount a host data volume to docker. But the container should have read and write permission to it, meantime, any changes on the data volumes should not affect the data in host.
I can image a solution that mount several data volumes to single folder, one is read only another is read and write. But only this second '-v' works in my command,
docker run -ti --name build_cent1 -v /codebase/:/code:ro -v /temp:/code:rw centos6:1.0 bash
only this second '-v' works in my command,
That might be because both -v options attempt to mount host folders on the same container destination folder /code.
-v /codebase/:/code:ro
^^^^^
-v /temp:/code:rw
^^^^^
You could mount those host folders in two separate folders within /code.
As in:
-v /codebase/:/code/base:ro -v /temp:/code/temp:rw.
Normally in this case I think you ADD the folder to the Docker image, so that any container running it will have it in its (writeable) filesystem, but writes will go to a different layer.
You need to write a Dockerfile in the folder above the one you wish to use, which should look something like this:
FROM my/image
ADD codebase /codebase
Then you build the container using docker build -t some-name <path>. These steps could be added to the build scripts of your app (maybe you will find some plugin to help there). Then you can docker run some-name.
The downside is that there is one copy to do and the image creation, but should you launch many containers they will share the same copy of the layer in read-only and write their own modifications to independent layers above.
Got one answer from nixun in github.
you can simply use overlayfs to fix this:
mount -t overlay overlay \
-olowerdir=/codebase,upperdir=/temp,workdir=/workdir /codebase_new
docker run -ti --name build_cent1 -v /codebase_new:/code:rw centos6:1.0 bash
This solution has a good flexibility. Create image with share folder would be a solution, but it cannot update folder data easily.
This answer is not for docker users but it will help anyone who uses Lima to manage their containers.
I was stuck trying to solve the issue with limactl and lima nerdctl . I thought it is worth sharing the fix so that it may help anyone in the community who's using lima instead of docker:
By default Lima mounts volumes as read only. to be make them writeable by default do the following:
Edit the file and set write: true under mount section
$ vim ~/.lima/default/lima.yaml
then restart lima
limactl list #this lists all running vms
limactl stop default #or name of the machine
limactl start default #or name of the machine
you would still need to specify mount options exactly as with docker
lima nerdctl run -ti --name build_cent1 \
-v /codebase/:/code/base:ro \
-v /temp:/code/temp:rw \
centos6:1.0 bash
For more information about lima, please check this out
I've noticed with docker that I need to understand what's happening inside a container or what files exist in there. One example is downloading images from the docker index - you don't have a clue what the image contains so it's impossible to start the application.
What would be ideal is to be able to ssh into them or equivalent. Is there a tool to do this, or is my conceptualisation of docker wrong in thinking I should be able to do this.
Here are a couple different methods...
A) Use docker exec (easiest)
Docker version 1.3 or newer supports the command exec that behave similar to nsenter. This command can run new process in already running container (container must have PID 1 process running already). You can run /bin/bash to explore container state:
docker exec -t -i mycontainer /bin/bash
see Docker command line documentation
B) Use Snapshotting
You can evaluate container filesystem this way:
# find ID of your running container:
docker ps
# create image (snapshot) from container filesystem
docker commit 12345678904b5 mysnapshot
# explore this filesystem using bash (for example)
docker run -t -i mysnapshot /bin/bash
This way, you can evaluate filesystem of the running container in the precise time moment. Container is still running, no future changes are included.
You can later delete snapshot using (filesystem of the running container is not affected!):
docker rmi mysnapshot
C) Use ssh
If you need continuous access, you can install sshd to your container and run the sshd daemon:
docker run -d -p 22 mysnapshot /usr/sbin/sshd -D
# you need to find out which port to connect:
docker ps
This way, you can run your app using ssh (connect and execute what you want).
D) Use nsenter
Use nsenter, see Why you don't need to run SSHd in your Docker containers
The short version is: with nsenter, you can get a shell into an
existing container, even if that container doesn’t run SSH or any kind
of special-purpose daemon
UPDATE: EXPLORING!
This command should let you explore a running docker container:
docker exec -it name-of-container bash
The equivalent for this in docker-compose would be:
docker-compose exec web bash
(web is the name-of-service in this case and it has tty by default.)
Once you are inside do:
ls -lsa
or any other bash command like:
cd ..
This command should let you explore a docker image:
docker run --rm -it --entrypoint=/bin/bash name-of-image
once inside do:
ls -lsa
or any other bash command like:
cd ..
The -it stands for interactive... and tty.
This command should let you inspect a running docker container or image:
docker inspect name-of-container-or-image
You might want to do this and find out if there is any bash or sh in there. Look for entrypoint or cmd in the json return.
NOTE: This answer relies on commen tool being present, but if there is no bash shell or common tools like ls present you could first add one in a layer if you have access to the Dockerfile:
example for alpine:
RUN apk add --no-cache bash
Otherwise if you don't have access to the Dockerfile then just copy the files out of a newly created container and look trough them by doing:
docker create <image> # returns container ID the container is never started.
docker cp <container ID>:<source_path> <destination_path>
docker rm <container ID>
cd <destination_path> && ls -lsah
see docker exec documentation
see docker-compose exec documentation
see docker inspect documentation
see docker create documentation
In case your container is stopped or doesn't have a shell (e.g. hello-world mentioned in the installation guide, or non-alpine traefik), this is probably the only possible method of exploring the filesystem.
You may archive your container's filesystem into tar file:
docker export adoring_kowalevski > contents.tar
Or list the files:
docker export adoring_kowalevski | tar t
Do note, that depending on the image, it might take some time and disk space.
Before Container Creation :
If you to explore the structure of the image that is mounted inside the container you can do
sudo docker image save image_name > image.tar
tar -xvf image.tar
This would give you the visibility of all the layers of an image and its configuration which is present in json files.
After container creation :
For this there are already lot of answers above. my preferred way to do
this would be -
docker exec -t -i container /bin/bash
The most upvoted answer is working for me when the container is actually started, but when it isn't possible to run and you for example want to copy files from the container this has saved me before:
docker cp <container-name>:<path/inside/container> <path/on/host/>
Thanks to docker cp (link) you can copy directly from the container as it was any other part of your filesystem.
For example, recovering all files inside a container:
mkdir /tmp/container_temp
docker cp example_container:/ /tmp/container_temp/
Note that you don't need to specify that you want to copy recursively.
The file system of the container is in the data folder of docker, normally in /var/lib/docker. In order to start and inspect a running containers file system do the following:
hash=$(docker run busybox)
cd /var/lib/docker/aufs/mnt/$hash
And now the current working directory is the root of the container.
you can use dive to view the image content interactively with TUI
https://github.com/wagoodman/dive
Try using
docker exec -it <container-name> /bin/bash
There might be possibility that bash is not implemented. for that you can use
docker exec -it <container-name> sh
On Ubuntu 14.04 running Docker 1.3.1, I found the container root filesystem on the host machine in the following directory:
/var/lib/docker/devicemapper/mnt/<container id>/rootfs/
Full Docker version information:
Client version: 1.3.1
Client API version: 1.15
Go version (client): go1.3.3
Git commit (client): 4e9bbfa
OS/Arch (client): linux/amd64
Server version: 1.3.1
Server API version: 1.15
Go version (server): go1.3.3
Git commit (server): 4e9bbfa
In my case no shell was supported in container except sh. So, this worked like a charm
docker exec -it <container-name> sh
The most voted answer is good except if your container isn't an actual Linux system.
Many containers (especially the go based ones) don't have any standard binary (no /bin/bash or /bin/sh). In that case, you will need to access the actual containers file directly:
Works like a charm:
name=<name>
dockerId=$(docker inspect -f {{.Id}} $name)
mountId=$(cat /var/lib/docker/image/aufs/layerdb/mounts/$dockerId/mount-id)
cd /var/lib/docker/aufs/mnt/$mountId
Note: You need to run it as root.
I use another dirty trick that is aufs/devicemapper agnostic.
I look at the command that the container is running e.g. docker ps
and if it's an apache or java i just do the following:
sudo -s
cd /proc/$(pgrep java)/root/
and voilá you're inside the container.
Basically you can as root cd into /proc/<PID>/root/ folder as long as that process is run by the container. Beware symlinks will not make sense wile using that mode.
Only for LINUX
The most simple way that I use was using proc dir, the container must be running in order to inspect the docker container files.
Find out the process id (PID) of the container and store it into some variable
PID=$(docker inspect -f '{{.State.Pid}}' your-container-name-here)
Make sure the container process is running, and use the variable name to get into the container folder
cd /proc/$PID/root
If you want to get through the dir without finding out the PID number, just use this long command
cd /proc/$(docker inspect -f '{{.State.Pid}}' your-container-name-here)/root
Tips:
After you get inside the container, everything you do will affect the actual process of the container, such as stopping the service or changing the port number.
Hope it helps
Note:
This method only works if the container is still running, otherwise, the directory wouldn't exist anymore if the container has stopped or removed
None of the existing answers address the case of a container that exited (and can't be restarted) and/or doesn't have any shell installed (e.g. distroless ones). This one works as long has you have root access to the Docker host.
For a real manual inspection, find out the layer IDs first:
docker inspect my-container | jq '.[0].GraphDriver.Data'
In the output, you should see something like
"MergedDir": "/var/lib/docker/overlay2/03e8df748fab9526594cfdd0b6cf9f4b5160197e98fe580df0d36f19830308d9/merged"
Navigate into this folder (as root) to find the current visible state of the container filesystem.
This will launch a bash session for the image:
docker run --rm -it --entrypoint=/bin/bash
On newer versions of Docker you can run docker exec [container_name] which runs a shell inside your container
So to get a list of all the files in a container just run docker exec [container_name] ls
I wanted to do this, but I was unable to exec into my container as it had stopped and wasn't starting up again due to some error in my code.
What worked for me was to simply copy the contents of the entire container into a new folder like this:
docker cp container_name:/app/ new_dummy_folder
I was then able to explore the contents of this folder as one would do with a normal folder.
For me, this one works well (thanks to the last comments for pointing out the directory /var/lib/docker/):
chroot /var/lib/docker/containers/2465790aa2c4*/root/
Here, 2465790aa2c4 is the short ID of the running container (as displayed by docker ps), followed by a star.
For docker aufs driver:
The script will find the container root dir(Test on docker 1.7.1 and 1.10.3 )
if [ -z "$1" ] ; then
echo 'docker-find-root $container_id_or_name '
exit 1
fi
CID=$(docker inspect --format {{.Id}} $1)
if [ -n "$CID" ] ; then
if [ -f /var/lib/docker/image/aufs/layerdb/mounts/$CID/mount-id ] ; then
F1=$(cat /var/lib/docker/image/aufs/layerdb/mounts/$CID/mount-id)
d1=/var/lib/docker/aufs/mnt/$F1
fi
if [ ! -d "$d1" ] ; then
d1=/var/lib/docker/aufs/diff/$CID
fi
echo $d1
fi
This answer will help those (like myself) who want to explore the docker volume filesystem even if the container isn't running.
List running docker containers:
docker ps
=> CONTAINER ID "4c721f1985bd"
Look at the docker volume mount points on your local physical machine (https://docs.docker.com/engine/tutorials/dockervolumes/):
docker inspect -f {{.Mounts}} 4c721f1985bd
=> [{ /tmp/container-garren /tmp true rprivate}]
This tells me that the local physical machine directory /tmp/container-garren is mapped to the /tmp docker volume destination.
Knowing the local physical machine directory (/tmp/container-garren) means I can explore the filesystem whether or not the docker container is running. This was critical to helping me figure out that there was some residual data that shouldn't have persisted even after the container was not running.
If you are using Docker v19.03, you follow the below steps.
# find ID of your running container:
docker ps
# create image (snapshot) from container filesystem
docker commit 12345678904b5 mysnapshot
# explore this filesystem
docker run -t -i mysnapshot /bin/sh
For an already running container, you can do:
dockerId=$(docker inspect -f {{.Id}} [docker_id_or_name])
cd /var/lib/docker/btrfs/subvolumes/$dockerId
You need to be root in order to cd into that dir. If you are not root, try 'sudo su' before running the command.
Edit: Following v1.3, see Jiri's answer - it is better.
another trick is to use the atomic tool to do something like:
mkdir -p /path/to/mnt && atomic mount IMAGE /path/to/mnt
The Docker image will be mounted to /path/to/mnt for you to inspect it.
My preferred way to understand what is going on inside container is:
expose -p 8000
docker run -it -p 8000:8000 image
Start server inside it
python -m SimpleHTTPServer
If you are using the AUFS storage driver, you can use my docker-layer script to find any container's filesystem root (mnt) and readwrite layer :
# docker-layer musing_wiles
rw layer : /var/lib/docker/aufs/diff/c83338693ff190945b2374dea210974b7213bc0916163cc30e16f6ccf1e4b03f
mnt : /var/lib/docker/aufs/mnt/c83338693ff190945b2374dea210974b7213bc0916163cc30e16f6ccf1e4b03f
Edit 2018-03-28 :
docker-layer has been replaced by docker-backup
The docker exec command to run a command in a running container can help in multiple cases.
Usage: docker exec [OPTIONS] CONTAINER COMMAND [ARG...]
Run a command in a running container
Options:
-d, --detach Detached mode: run command in the background
--detach-keys string Override the key sequence for detaching a
container
-e, --env list Set environment variables
-i, --interactive Keep STDIN open even if not attached
--privileged Give extended privileges to the command
-t, --tty Allocate a pseudo-TTY
-u, --user string Username or UID (format:
[:])
-w, --workdir string Working directory inside the container
For example :
1) Accessing in bash to the running container filesystem :
docker exec -it containerId bash
2) Accessing in bash to the running container filesystem as root to be able to have required rights :
docker exec -it -u root containerId bash
This is particularly useful to be able to do some processing as root in a container.
3) Accessing in bash to the running container filesystem with a specific working directory :
docker exec -it -w /var/lib containerId bash
Often times I only need to explore the docker filesystem because my build won't run, so docker run -it <container_name> bash is impractical. I also do not want to waste time and memory copying filesystems, so docker cp <container_name>:<path> <target_path> is impractical too.
While possibly unorthodox, I recommend re-building with ls as the final command in the Dockerfile:
CMD [ "ls", "-R" ]
I've found the easiest, all-in-one solution to View, Edit, Copy files with a GUI app inside almost any running container.
mc editing files in docker
inside the container install mc and ssh: docker exec -it <container> /bin/bash, then with prompt install mc and ssh packages
in same exec-bash console, run mc
press ESC then 9 then ENTER to open menu and select "Shell link..."
using "Shell link..." open SCP-based filesystem access to any host with ssh server running (including the one running docker) by it's IP address
do your job in graphical UI
this method overcomes all issues with permissions, snap isolation etc., allows to copy directly to any machine and is the most pleasant to use for me
I had an unknown container, that was doing some production workload and did not want to run any command.
So, I used docker diff.
This will list all files that the container had changed and therefore good suited to explore the container file system.
To get only a folder you can just use grep:
docker diff <container> | grep /var/log
It will not show files from the docker image. Depending on your use case this can help or not.
Late to the party, but in 2022 we have VS Code