New to docker.
Need to install docker on a RHEL 7 (no gui) system.
Does the RHEL 7 installation come with docker already on it? If not, where do I get it from? (I cannot use the docker software at docker.com, it has to come from RedHat - government rules, not mine)
Once procured, how do I install it on a system that is not connected to the internet.
I hope I've made my request as simple as possible, let the questions begin.
Red Hat's build of docker is available in the Red Hat Enterprise Linux 7 Extras channel, but only for the Server variant of the product. You can download individual packages from the Customer Portal after login, but it is going to be a bit cumbersome because the docker package has multiple dependencies.
Alternatively, you can use the reposync tool to mirror the entire Extras channel on a network-connected machine which has a subscription. Or you can use yum in download-only mode and copy over the RPMs stored in the cache directory (but please copy them to a regular directory on the target, and use yum install to install them).
Fire up a centos system.
$ sudo yumdownloader docker --resolve
Copy the RPMs over to your RH machine and run:
$ sudo rpm -ivh *rpm
$ sudo systemctl start docker
Gen rpm on CentOS 7 with docker:
$ yumdownloader --resolve docker-ce
Then, install on target:
$ rpm -ivh docker-ce-19.03.11-3.el7.x86_64.rpm
Related
I want that all Linux Ubuntu servers I work with use the same docker version. I also want that if I run an apt-get upgrade command the docker related packages stay on this version and don't auto upgrade.
The first part was easy, it was explained in the official docker doc. For the second part I used apt-mark hold docker-ce after installing the specific docker version.
But after an apt-get upgrade a few weeks later I noticed that the containerd.io version shown by the docker version command was different than before.
I am not sure if this has any consequences. So my question is what packages, if any, should I apt-mark hold besides docker-ce?
docker-ce-cli? containerd.io? runc?
Or should I only hold docker-ce and let the other packages do their upgrades?
I downloaded the RPM package from the official website, but I still need to download some dependencies when I install it. I need to install docker-ce without any network or repository at all, so I need all the RPM packages I depend on and the order in which they are installed.
Docker-CE Version: 18.03+
Only way to install if there is no internet is download tar and extract.
Steps available at :- Docker Install Steps
tar can be downloaded from
Binary repo
if you don't want to install the binary file and thus configure it from scratch Docker, you can download all the RPM packages needed for your system, upload them to your offline machine, and install them.
Suppose you are on Centos 7.7, spin up a docker centos container, find all the needed dependencies. Download them. Upload and install them.
# In an online machine
docker run --rm -v ${PWD}/bin:/tmp -it centos:7.7.1908 bash # Run an online container similar to your offline machine
# In the online container:
cd /tmp
yum-config-manager --add-repo=https://download.docker.com/linux/centos/docker-ce.repo # Add Docker repo
yum makecache fast # Update Yum cache
yum list docker-ce --showduplicates | sort -r # Choose a version
yumdownloader --resolve docker-ce-20.10.5-3.el7 # Download all non-installed RPM depencencies
Upload all the RPM packages to your offline machine. You can make a tar out of them:
tar cvzf docker-rpm-deps.tar.gz * # Create an archive of all the RPMs
Install all the RPMs
# In the offline machine
tar xzvf docker-rpm-deps.tar.gz -C /tmp # Exctract archive
cd /tmp
rpm -ivh --replacefiles --replacepkgs *.rpm # Install all .rpm in the current folder
Voila! Now you just need to enable and start docker.
systemctl enable docker.service
systemctl start docker.service
If, when you are in the offline machine, you still miss an RPM package you can download all the needed RPMs with the command below
# Instead of using yumdownloader
repotrack -a x86_64 -p ./docker-rpm-pkgs docker-ce-20.10.5-3.el7 # Download all RPM dependencies, even the already installed ones
you must download the DEB package and install it manually and manage upgrades completely manually. This is useful in situations such as installing Docker on air-gapped systems with no access to the internet.
Install from a package
If you cannot use Docker’s repository to install Docker CE, you can download the .deb file for your release and install it manually. You will need to download a new file each time you want to upgrade Docker CE.
1.Go to [https://download.docker.com/linux/ubuntu/dists/], choose your Ubuntu version, browse to pool/stable/ and choose amd64, armhf, ppc64el, or s390x. Download the .deb file for the Docker version you want to install.
Note: To install an edge package, change the word stable in the URL to edge.
Install Docker CE, changing the path below to the path where you downloaded the Docker package.
$ sudo dpkg -i /path/to/package.deb
and run
$ sudo docker version
to peresent docker version and succeed of inestallation.
A beginner's question; how does Docker handle underlying operating system variations when using the RUN command?
Let's take, for example, a very simple Official Docker Hub Dockerfile, for JRE 1.8. When it comes to installing the packages for java, the Dockerfile uses apt-get:
RUN apt-get update && apt-get install -y --no-install-recommends ...
To the untrained eye, this appears to be a platform-specific instruction that will only work on Debian-based operating systems (or at least ones with APT installed).
How exactly would this work on a CentOS installation, for example, where the package manager would be yum? Or god forbid, something like Solaris.
If this pattern of using RUN to fork arbitrary shell commands is prevalent in docker, how does one avoid inter-platform, or even inter-version, dependencies?
i.e. what if the Dockerfile writer has a newer version of (say) grep than I do, and they've used some new CLI flag that isn't available on earlier versions?
The only two outcomes from this can be: (1) RUN command exits with non-zero exit code (2) the Dockerfile changes the installed version of grep before running the command.
The common point shared by all Dockerfiles is the FROM statement. It is the first line in the file and indicates the parent Docker image you're building on. A typical base image could be one with Ubuntu (i.e.: https://hub.docker.com/_/ubuntu/). The snippet you share in your question would fit well in an Ubuntu image (with apt-get) but not in a CentOS image.
In summary, you're installing docker in your CentOS system, but you're building a Docker image with Ubuntu in it.
As I commented in your question, you can add FROM statement to specify which relaying OS you want. for example:
FROM docker.io/centos:latest
RUN yum update -y
RUN yum install -y java
...
now you have to build/create the image with:
docker build -t <image-name> .
The idea is that you'll use the OS you are familiar with (for example, CentOS) and build an image of it. Now, you can take this image and run it above Ubuntu/CentOS/RHEL/whatever... with
docker run -it <image-name> bash
(You just need to install docker in the desired OS.
Following the section at Making your own customised boot2docker ISO, i wrote the Dockerfile below to install the vim package:
FROM boot2docker/boot2docker
RUN apt-get update && apt-get install -y vim
RUN /make_iso.sh
CMD ["cat", "boot2docker.iso"]
Then executed these commands successfully:
docker build -t my-boot2docker-img . && docker run --rm my-boot2docker-img > boot2docker.iso
I created a virtual machine using this iso image and logged into it. I've expected the vim is now available on my shell but it was not. From the build process console logs, i saw the vim installed successfully. However it is apparently not included in the iso.
Can someone please tell me, what i've missed here?
You only installed vim in the build container that produces the final boot2docker iso. To get the desired result you need to install any packages/data at $ROOTFS in the build container. For some hints on how to accomplish this with apt-get see this answer.
But first you should ask yourself why you need vim in a VM that is only meant as a transparent proxy for mac/windows users.
Edit:
As you got valid reasons to build your own boot2docker iso, have a look at the boot2docker repo.
The dockerfile broken down:
install build dependencies in the build container
download and compile a linux kernel with aufs support, copy to $ROOTFS
download and extract TinyCore distribution at $ROOTFS
download and extract TinyCore packages defined in $TCZ_DEPS to $ROOTFS
build and install VMware tools and other helpers at $ROOTFS
export $ROOTFS as new iso
I'd probably look into extending on step 4 first, i.e. simply download packages from the TinyCore repo.
I'm relatively new to Docker.
I have launch a boot2docker host using docker-machine create -d.
Managed to connect to it, and run few commands. All good.
However, when trying to create a basic http server image, based on centos..
"yum install" simply fails. No matter what is the package.
This is my Docker file:
FROM centos
MAINTAINER Amir
#Install Apache
RUN yum install httpd
When running:
docker build .
It's starting to build the image, and everything looks good.. but then fails with:
Your transaction was saved, rerun it with:
yum load-transaction /tmp/yum_save_tx.2015-09-18.15-10.q5ss8m.yumtx
SECURITY WARNING: You are building a Docker image from Windows against a non-Windows Docker host. All files and directories added to build context will have '-rwxr-xr-x' permissions. It is recommended to double check and reset permissions for sensitive files and directories.
The command '/bin/sh -c yum install httpd' returned a non-zero code: 1
Any idea what am I doing wrong?
Thanks in advance.
If you look bit earlier than the last message, you have a good chance to see something like this:
Total download size: 24 M
Installed size: 32 M
Is this ok [y/d/N]: Exiting on user command
Your transaction was saved, rerun it with:
which means you have to change the default choice, e.g.
#Install Apache
RUN yum install -y httpd