Share and learn in the Docker community.
I’m new to Docker and would like some advice on where to find documentation.
I intend to use it to install pre-built Applications, in Windows, Linux and TrueNAS environments.
My first doubt is how applications installed in different containers can share information, for example folders on the file System.
Many thanks in advance.
Have you tried https://docs.docker.com?
A named volume (will be listed indocker volume ls) can be backed by binding a host folder, or cifs/nfs remote share. A named volume can be used in one or more container.
There are also “volume” binds (also called bind mounts, won’t be listed in docker volume ls) that allow to map a host folder into a container folder.
For more details, see:
Thanks, I’ve started reading the documentation.
Being all web applications, I wonder if it’s better individual containers for each app or a single apache server with multiple virtual websites.
The applications are all for private use, not accessible externally.
In the case of an apache server I would install it in an xubuntu virtual machine. Even Docker I would install in a Xubuntu VM.
What creates less problems, for example for overall use of resources.
Can I start with the Community Edition?
Sure, docker-ce can be used in all stages, from development to production. It doesn’t require a subscription or licensing. Just make sure to install docker-ce from Docker’s repositories, and not docker.io from the Ubuntu repos or the snap version.
It really depends on what you want to do. Usually every standalone application should be its own container.
Are you Refering to the overhead of running one central apache instance with all websites vs. a container with apache per website? The overhead should be quite small. It also depends whether you want to create images of your website or just want to bind a host folder into the container.
No, I was referring to a manually installed apache server, without docker.
The differences and advantages of docker compared to a traditional installation.
I understand for those who have to develop an application, but for those who only have to use them, they seem more problems than advantages.
I installed Docker Desktop on Ubuntu Mate, following all informations, including generating the GPG passphrases.
Once installed, I look for the first application (ProjeQtOr).
If I want to install it on an apache server I have all the instructions directly from the official page. After that I just have to do https:something and the application starts.
In docker meanwhile I have dozens of ProjeQtor versions and none official. How to trust? I’ll take the one with the highest score. Pull. Run.
And then what do I do? Where is the application? How do I call it back wit the browser?
It’s not easy at all.
It depends on how experiences you are with container. For an inexperienced user this might be true. Working with containers might be frustrating if the concepts and mechanics are not understood.
Docker Desktop is aimed at developers. If you want to run containers in production, you should consider using docker-ce instead.
The stars are just indicators. You should avoid repositories with no or insufficient description and images that are not frequently updated. Bitnami and Linuxserver usually patch their images frequently, have decent descriptions and usually many stars. When official images are less frequently patched than those images are often a better alternative. But ultimately it’s up to you.
This indicates two things: you didn’t seem to exercise the docker getting started tutorials and/or the repository didn’t have a sufficient description.
The getting started tutorial should have covered publishing container ports to host ports, and that a published container port can be accessed using the host-ip:host-port.
It’s like when people are learning how to drive a car. It might look complicated for a beginner, but every experienced driver drives without even having to think about all the details a beginner struggles with.
If you want to understand the concepts and want to know how things need to be done in docker, I can highly recommend this fabulous, free, self-paced docker training: https://container.training/intro-selfpaced.yml.
Note: there seem to be a problem with the slide deck at the moment. Instead of showing the slides, it downloads the first page. I can’t say when they are going to fix it.
I can’t find guides for Docker-CE, only for Docker Desktop and Docker Engine.
Where can I find something for Docker - CE?
Docker Engine is Docker CE. It is because CE means community edition and there was an EE (enterprise edition) too which was bought by Mirantis. So currently Docker Engine or in other words Docker CE is what you can run on Linux and you need a virtual machine on other platforms to run Linux containers. Docker Desktop runs the VM for you.
The index page of https://container.training had an incomplete link. It is fixed now, and the correct link is https://container.training/intro-selfpaced.yml.html.