We are currently running Red Hat 5. But I saw documentation that says docker is only supported on Red Hat 7. So we have to upgrade to Red Hat 7 or we can't use docker at all on RHEL 5? Alternatively we can consider to switch to Ubuntu.
How do others solve the similar issue?
You will need to upgrade from RHEL5 to use Docker.
The official Docker release deprecated RHEL6 support from 1.7 (and inadvertently broke it in 1.7.0 but fixed in 1.7.1). Support for RHEL6 was dropped in Docker 1.8. Since then, a RHEL7 based distro with a 3.10+ kernel has been required.
There is a docker-io-1.7.1-2 package available on EPEL for RHEL6.5+ based distros. RHEL6 runs an older 2.6 kernel with back ported fixes so docker can work. This kernel must be at 2.6.32-431 or higher.
RHEL doesn't support AUFS which is the most commonly used Docker storage driver. By default RHEL uses a loopback storage driver which is not production ready. The EPEL packages provide docker-storage-setup to setup thin provisioned LVM. You need to do this setup manually if you want to run the docker.com packages.
Personally I would recommend going with a recent debian based distribution running the official docker packages for timely updates. If you are on EC2, Amazons AMI will do nicely though.
Related
I was told it's better not to use latest in Docker File, but how can I find alternatives?
According to: https://ubuntu.com/download/desktop the latest version of ubuntu is Ubuntu 22.04.1 LTS but when I go to: https://hub.docker.com/_/ubuntu/tags I see strange tags like: bionic what is that?
and 22.10 this is a future version? how is that possible?
and while I could fine 22.04 I could not find 22.04.1
There are many problems involving the usage of latest tag on a docker image. The application is constantly changing and with it its architecture as well. While pulling an image with the latest tag, you use these changes as well. This may be good in a personal project sometimes but in a large scale application, you dont want your application to change drastically. Example:
While working on a dockerized application, we incorporated db connector to session storage redis db, the connector connected to redis at the start of the application and if it was unsuccessful, the application would not start. Every update/change on the host machine with running application meant deploying redis as well as we were using the latest tag.
22.04 Ubuntu is the latest LTS build, but there also is experimental 22.10 (ref. Ubuntu 22.10
I am very new to docker. I have installed docker desktop on my mac. When i execute docker version it is showing OS/Arch:linux/amd64 under server docker engine. I am assuming this means that docker installed linux kernel on top of my mac OS using hypervisor to manage linux based containers. if this linux kernel got updated, will it going break the functionalities of existing images?
Why am I asking this question?
Recently after updating my mac OS to 10.15.2, things started breaking because of openssl and ruby-2.3.x compatibility issues. And I was told, we could solve these type of issues using docker since it is independent of host OS?
But docker itself has own linux kernel, Will i be going to face this issue if linux kernel got updated?
Thanks in advance
You got those errors because you were depending software libraries available on the machine. They are not related to kernel. Any such software dependencies should be bundled with the docker image. Linux kernel upgrades never break user space.
I've bought a Debian 8 VPS for 3e per month https://www.pulseheberg.com/vps/simple.
I would like to install docker engine but it not works ( cause it need a kernel >= 3.10)
Do you have any idea for install docker on my server ?
Related?
You can't. Sorry to bear the bad news.
Docker backport-supports kernel 3.10 but not below. Here is a copy/paste from their doc:
Prerequisites
Docker requires a 64-bit installation regardless of your Debian version. Additionally, your kernel must be 3.10 at minimum. The latest 3.10 minor version or a newer maintained version are also acceptable.
Kernels older than 3.10 lack some of the features required to run Docker containers. These older versions are known to have bugs which cause data loss and frequently panic under certain conditions.
I want to install docker 1.3.1 on my centos 6.5 environment but I have no idea how to find it in the epel. I'm quite new to docker. Can anyone help me out? Thanks
Clearly stated in the Docker documentation:
Docker runs on CentOS 7.X.
CentOS 6.5 is not CentOS 7.X. Docker is not available for your old operating system.
Furthermore, you didn't give any details about your computer, but you should remain aware that Docker only works on 64-bit systems.
By the way, you should take better care of your computer; in CentOS, the minor version number is updated automatically by the package manager. So the fact that you are two versions behind (CentOS 6 is currently on 6.7) indicates that you are not performing updates to your packages, and could have various security vulnerabilities. You should update your system regularly, by simply running yum update.
I have been working with LXC containers, the basic tutorials and some networking and it seems to me that its a very straightforward and simple way to create a pure distribution on top of my host.
Current list of templates available does not however list the RHEL x.x distribution. There is CentOS.
I see that Red Hat has supported some efforts in LXC with the libvirt driver, however that shows as deprecated on the site and everything is pointing to their Atomic host which I am experimenting anyways, however, that seems more of a docker way. There might be some variations of docker which ultimately may give me a bare minimum container running a full distro.
I am OK getting more into docker but what I expect at this moment is to run as a simple LXC container with RHEL 6.x distro. Is there no way to run a RHEL LXC container ?
it is indeed unfortunate that redhat plans to discontinue libvirt support for lxc. even within rhel7, so that means rhel6 may be the last version where it will be supported for the lifetime of that release.
as an alternative, there are packages for lxc in epel: https://dl.fedoraproject.org/pub/epel/6/x86_64/repoview/lxc.html
they are even easier to use than libvirt-lxc
as for the template, in either case you should be able to use the centos template with little modification. all the packages are the same and really only the repo sources should point to redhat instead of centos.