I'm new to docker and pulled plesk panel docker image from this link. I succesfully built and ran this container using following command and created some data in it.
docker run -d -p 80:80 -p 443:443 -p 8880:8880 -p 8443:8443 -p 8447:8447 plesk/plesk
Whenever I restart container from image, I lost my data on plesk panel. Fair enough, because I'm creating a fresh container whenever I started container from scratch. I know that I need to create volumes and save data in it and mount container everytime from these volumes, it's ok. But here is my question, which file inside container will I map with host? How to decide it? Is it enough to create a volume with /data directory in every container? How to find container saves data in which of its directories?
Thanks in advance.
Related
I'm working on a project using NodeRed deployed with docker and I would like to save the state of my deployment, including flows, settings and new added modules so that I can save the image and load it on another host replicating exactly the same NodeRed instance.
I created the container using:
docker run -itd --name my-nodered node-red
After implementing the flows and installing some custom modules, with the container running I used this command:
docker commit my-nodered my-project-nodered/my-nodered:version1
docker save my-project-nodered/my-nodered:version1 > tar-archive.tar.gz
And on another machine I'd imported the image using:
docker load < tar-archive.tar.gz
And run it using:
docker run -itd my-project-nodered/my-nodered:version1
And I obtain a vanilla NodeRed docker container with a default /data directory and just the files on the data directory maintained.
What am I missing? It could be possibile that my /data directory is overwrittenm as well as my settings.js file in the home directory? And in this case, which is the best practice to achieve my target?
Thank you a lot in advance
commit will not work, as you can see that there is volume defined in the Dockerfile.
# User configuration directory volume
VOLUME ["/data"]
That makes it impossible to create a derived image with any different content in that directory tree. (This is the same reason you can't create a mysql or postgresql image with prepopulated data.)
docker commit doesn't consider volumes at all, so you'll get an unchanged image with nothing preloaded in it.
You can see the offical documentation
Managing User Data
Once you have Node-RED running with Docker, we need to ensure any
added nodes or flows are not lost if the container is destroyed. This
user data can be persisted by mounting a data directory to a volume
outside the container. This can either be done using a bind mount or a
named data volume.
Node-RED uses the /data directory inside the container to store user
configuration data.
nodered-user-data-in-docker
one way is to restore the your config file on another machine, for example backup-config then
docker run -it -p 1880:1880 -v $PWD/backup-config/:/data --name mynodered nodered/node-red-docker
or if you want to full for some repo then you can try
docker run -it --rm -v "$PWD/$(wget https://raw.githubusercontent.com/openenergymonitor/oem_node-red/master/flows_emonpi.json)":/data/ nodered/node-red-docker
I am trying to use volumes.
I created an app that reads from and writes to a file.
Either if I run it like that (without a volume):
docker run -p 3000:3000 hello-express
or if I run it like that (with a volume):
docker run -p 3000:3000 -v myvol:/myvol hello-express
I get the same result: the data is persisted after I stop and start the contianer, but it's deleted after I remove the container and run it again.
So something is wrong here.
You can try to create the Volume in DockerFile and attach it while running the command with the container you want. As volume are isolated with container and they have no dependency to the specific container.
You can refer to this good article of volumes as well. Hope it helps.
I run Joomla image with :
docker run --name some-joomla --link test-mysql:mysql -p 8080:80 -d joomla
How can I change Joomla files ?
I think it is possible when specifying volume mapping, but I did not use that to run Joomla: is there a way to access Joomla files now ?
If I understand your question correctly, this thread should help you out.
Commit your container and create a new image from it.
Run a container from your just created image (and add the volume you need). Watch out for the port mappings, you either have to use other ports temporarily to check functionality of your new container, or you do step 3 beforehand.
If all works out, stop the old one.
If you want to check what's currently in the container, you can jump into it by running docker exec -it some-joomla bash (or sh, whatever Shell is installed in this image). You can then look for the files you want inside the container.
If you found them and you want to copy them on your local machine, you can run docker cp some-joomla:/your/path /path/on/local/machine.
I did the following and lost all the changed data in my Docker container.
docker build -t <name:tag> .
docker run *-p 8080:80* --name <container_name> <name:tag>
docker exec (import and process some files, launch a server to host them)
Then I wanted to run it on a different port. docker stop & docker run does not work. Instead I did
docker stop
docker rm <container_name>
docker run (same parameters as before)
After the restart I saw the changes that happened in the container at 1-3 had disappeared, and had to re-run the import.
How do I do this correctly next time?
what you have to do is build the image from the container you just stopped after making changes. Because your old command still using the old image which doesn't have new changes(you have made changes in container which you just stopped not in image )
docker commit --help
Usage: docker commit [OPTIONS] CONTAINER [REPOSITORY[:TAG]]
Create a new image from a container's changes
docker commit -a me new_nginx myrepo/nginx:latest
then you can start container with the new image you just built
but if you dont want create image with the changes you made(like you dont want to put config containing password in the image) you can use volume mount
docker run -d -P --name web -v /src/webapp:/webapp training/webapp python app.py
This command mounts the host directory, /src/webapp, into the container at /webapp. If the path /webapp already exists inside the container’s image, the /src/webapp mount overlays but does not remove the pre-existing content. Once the mount is removed, the content is accessible again. This is consistent with the expected behavior of the mount command.
Manage data in containers
Every time you do a docker run it will spin up a fresh container based on your image. And once a container is started, there are very few things that docker allows you to change with the docker update. So instead, you should preserve your data in an external volume that needs to persist between instances of a container. E.g.
docker run -p 8080:80 -v app-data:/data --name <container_name> <name:tag>
The volume name (app-data) and mount point in the container (/data) can be changed for your own requirements. Then when you destroy and restart a new container, you can mount the same volume in the new container.
There is something I'm missing in many docker examples and that is persistent data. Am I right if I conclude that every container that is stopped will lose it's data?
I got this Prestashop image running with it's internal database:
https://hub.docker.com/r/prestashop/prestashop/
You just run docker run -ti --name some-prestashop -p 8080:80 -d prestashop/prestashop
Well you got your demo then, but not very practical.
First of all I need to hook an external MySQL container, but that one will also lose all it's data if for example my server reboots.
And what about all the modules and themes that are going to be added to the prestashop container?
It has to do with Volumes, but it is not clear to my how all the the host volumes needs to be mapped correctly and what path to the host is normally chosen. /opt/prestashop er something?
First of all, I don't have any experience with PrestaShop. This is an example which you can use for every docker container (from which you want to persist the data).
With the new version of docker (1.11) it's pretty easy to 'persist' your data.
First create your named volume:
docker volume create --name prestashop-volume
You will see this volume in /var/lib/docker/volumes:
prestashop-volume
After you've created your named volume container you can connect your container with the volume container:
docker run -ti --name some-prestashop -p 8080:80 -d -v prestashop-volume:/path/to/what/you/want/to/persist :prestashop/prestashop
(when you really want to persist everything, I think you can use the path :/ )
Now you can do what you want on your database.
When your container goes down or you delete your container, the named volume will still be there and you're able to reconnect your container with the named-volume.
To make it even more easy you can create a cron-job which creates a .tar of the content of /var/lib/docker/volumes/prestashop-volume/
When really everything is gone you can restore your volume by recreating the named-volume and untar your .tar-file in it.