I wonder if it's possible to dump a whole container to a tgz archive, so it can be bakuped or moved to another server. I know I can do it with an image, so I can pusblih the container as an image and dump it but would be nice to be able to do it directly.
Thanks in advance!
Yes it is possible first you need to publish your container that will create a local image and then you export that image this will create an archive
eg
lxc list on my machine
TestContainer | RUNNING
Publish the Container
lxc publish TestContainer --alias TestContainerPublish --force
and export the image in curr dir
lxc image export TestContainerPublish .
And than you are done
Related
I use docker-compose for local development on my Mac. I have multiple images being built with docker compose. My docker and docker-compose set up is very standard. Now I want to share my locally built image file with someone. Where are these local files stored?
Searching a bit gave me answers like:
~/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/Docker.qcow2
But then how can I extract one image from this and share? I tried running the tty that is present with it, but to no avail.
Docker Version: 18.03 Docker for Mac
Docker compose Version: 2
If you have docker-hub account (which is free), then you can use docker push command to save docker image into registry and use docker pull to pull on other machine.
Another solution is to use save + import commands.
For that you can use docker save and docker import commands.
docker#default:~$ docker save --help
Usage: docker save [OPTIONS] IMAGE [IMAGE...]
Save one or more images to a tar archive (streamed to STDOUT by default)
Options:
-o, --output string Write to a file, instead of STDOUT
docker#default:~$
After that you have TAR file on your file system (check -o value) then transfer the file to another machine and execute docker import
docker#default:~$ docker import --help
Usage: docker import [OPTIONS] file|URL|- [REPOSITORY[:TAG]]
Import the contents from a tarball to create a filesystem image
Options:
-c, --change list Apply Dockerfile instruction to the created image
-m, --message string Set commit message for imported image
docker#default:~$
Apparently, the solution with docker-compose is using the docker save command. We do not need to know the locations of images as #fly2matrix mentioned. We can use the docker save command to save the image in TAR file.
docker save --output image-name.tar image-name:tag
Then this image can be shared and loaded by other users through:
docker load --input image-name.tar
I have installed docker in a system which has no connection to Internet so to run an image with docker, I had to download a simple image from this and from another system. Then I put this image in my offline system in this path : C:\Users\Public\Documents\Hyper-V\Virtual hard disks
but when I run docker run hello-world in cmd I see this message:
Unable to find image 'hello-world:latest' locally
and tries to download hello-world image form Internet but it has to no connection to the Internet so it field. Now I want to know where I should put my images in to be visible to docker?
You can do it the easy way without messing around with folders, by exporting the docker image from any other machine with access to internet:
pull the image on a machine with internet access.
$docker pull hello-world
save that image to a .tar file.
$ docker save --output hello-world.tar {your image name or ID}
copy that file to any machine.
load the .tar file to docker.
$docker load --input hello-world.tar
Check out:
https://docs.docker.com/engine/reference/commandline/image_save/
https://docs.docker.com/engine/reference/commandline/load/#examples
You are trying to start a container using the dockerfile. You need to first build the image from dockerfile. You can do this via
docker build -t < image name > < path >
You will require the internet connection while building the image.
You can check the image in your system using
docker images
Once you build the docker image you can start the container without internet connection using
docker run < image name >
Also you can export the same image using docker save and docker load functionalities.
Docker runs in a client-server architecture environment just almost like git. It can pull resources from the server online with the client on "your machine".
The command $docker pull hello-world requires connection to the server as part of docker itself.
I have an app with a Dockerfile content that looks like
Dockerfile
FROM SOME_NUMBERS.dkr.ecr.us-east-1.amazonaws.com/app_name:SOME_HEX_VALUE
COPY docker/app/bin/startup.sh /usr/bin/
CMD ["/usr/bin/startup.sh"]
I don't want to pull the image from amazon anymore instead I'd like to "pull" from the already-existing local image pulled the after the first docker-compose up --build command was ran.
When I do docker images I get
SOME_NUMBERS.dkr.ecr.us-east-1.amazonaws.com/app_name SOME_HEX_VALUE SOMESHORT_HEX 2 days ago 1.54 GB which means the image is local already. I understand this
if the host has the image you want docker-compose to use on it it will use that image but if the host doesn't have it, it will go to docker hub or whatever you have setup in your config for registries
So I changed the Dockerfile content to this:
FROM IMAGE_ID:SOME_HEX_VALUE where IMAGE_ID is the image id of the repository I want when I do docker images but then I get Service 'app' failed to build: repository SOMESHORT_HEX not found: does not exist or no pull access and I'd like to know how to tell Docker to use the local image instead of trying to pull from the amazon url. Any ideas?
First pull the images from the remote repository in your local Docker engine:
docker pull SOME_NUMBERS.dkr.ecr.us-east-1.amazonaws.com/app_name:SOME_HEX_VALUE
Now, give the image a new local tag:
docker tag SOME_NUMBERS.dkr.ecr.us-east-1.amazonaws.com/app_name:SOME_HEX_VALUE my-image-name
Now you can simply refer to my-image-name, as in:
FROM my-image-name
You should:
FROM IMAGE_ID
Or, this is already ok:
FROM SOME_NUMBERS.dkr.ecr.us-east-1.amazonaws.com/app_name:SOME_HEX_VALUE
Where SOME_HEX_VALUE is the tag version (the second column in docker images). Note that if the images is present in your computer, docker won't try to pull it again.
I was trying to add some files inside a docker container like "touch". I found after I shutdown this container, and bring it up again, all my files are lost. Also, I'm using ubuntu image, after shutdown-restart the same image, all my software that has been installed by apt-get is gone! Just like running a new image. So how can I save any file that I created?
My question is, does docker "store" all its file systems like "/tmp" as memory file system, so nothing is actually saved to disk?
Thanks.
This is normal behavoir for docker. You have to define a volume to save your data, those volumes will exist even if you shutdown your container.
For example with a simple apache webserver:
$ docker run -dit --name my-apache-app -v "$PWD":/usr/local/apache2/htdocs/ httpd:2.4
This will mount your "current" director to /usr/local/apache2/htdocs at the container, so those files wil be available there.
A other approach is to use named volumes, those ones are not linked to a directory on your disk. Please refer to the docs:
Docker Manage - Data
When you start a container using docker run command,docker run ubuntu, docker starts a new container based on the image you specified. Any changes you make to the previous container will not be available, as this is a new instance spawned from the base image.
There a multiple ways to persist your data/changes to your container.
Use Volumes.
Data volumes are designed to persist data, independent of the container’s lifecycle. You could attach a data volume or mount a host directory as a volume.
Use Docker commit to create a new image with your changes and start future containers based on that image.
docker commit <container-id> new_image_name
docker run new_image_name
Use docker ps -a to list all the containers. It will list all containers including the ones that have exited. Find the docker id of the container that you were working on and start it using docker start <id>.
docker ps -a #find the id
docker start 1aef34df8ddf #start the container in background
References
Docker Volumes
Docker Commit
I have installed Docker for Windows. I have downloaded HDP_2.5_docker.tar from http://hortonworks.com/downloads/#sandbox which is a 10 GB file.
How can I load an image tar file? I have tried this command:
docker import HDP_2.5_docker.tar
You can use docker load
Usage: docker load [OPTIONS]
Load an image from a tar archive or STDIN
Git bash console:
docker load < HDP_2.5_docker.tar
Windows cmd:
docker load -i windowsservercore.tar
Firstly, put the tar file under your user folder: i.e: C:\Users\yourName\xxx.tar
Secondly, run the Docker load CMD:
docker load -i xxx.tar
After it is done, we could see the file is loaded as Docker images by running CMD:
docker images
you can do:
docker image import file.tar images_name:image_tag
Load the desired docker file, assuming you are in the same directory as the tar file, you can use -
$ docker load -i filename.tar
On successful import, you will see a success message along with the image ID
Check in the docker images for the image ID that you just received:
docker images
You will see the docker loaded successfully in the docker images list. However, there is one thing worth mentioning in case you might get confused; the date reflected in the command output might reflect the date when docker is created. Assuming, docker got created 5 days ago then the same will be shown in the output. Better way to confirm if your docker is loaded or not is to check for the image ID or repo and tag name (if you know).
You can finally run the docker using the command -
$ docker run -it image-ID