A Technical I.T./DevOps Blog
Problem scenario
You are trying to install docker-engine on Ubuntu Linux, but you get this error:
“docker-engine : Depends: libsystemd-journal0 (>= 201)”
Solution
This solution assumes your Ubuntu Linux server has access to the Internet.
1. Run this command exactly once:
echo ‘deb http://cz.archive.ubuntu.com/ubuntu trusty main’ >> /etc/apt/sources.list.d/docker.list
2. Try to install docker-engine again.
…
Problem scenario
You are using Linux (Ubuntu 14.04) and trying to run Docker for the first time. You run docker ps or docker version and you see this message:
“Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?”
How do you fix this problem to get Docker to work?
Solution
Run this command:
cat /var/log/upstart/docker.log | grep -i docker | grep -i linux
If you see this: ‘ level=fatal msg=”Your Linux kernel version 2.6.32-042stab116.2 is not supported for running docker.
…
UPDATE: If you are using RHEL 8.x use these directions instead of the ones below.
Problem scenario
You want to install Docker on an AWS instance of RedHat Linux (version 7.x or below). You do not want to use CentOS packages. What do you do?
Solution
For RedHat Linux running via AWS, you have to run one command to enable numerous yum repositories.
…
Continue reading “How Do You Install Docker on an AWS Instance of RHEL?”
Problem scenario: You are using RHEL 7.x via AWS. You want to install Kubernetes. What do you do?
Solution
1. Log into the Linux server as ec2-user. Then run this command:
sudo yum-config-manager –enable rhui-REGION-rhel-server-extras rhui-REGION-rhel-server-optional
2. Create this file: /etc/yum.repos.d/kubernetes.repo
3. Have this be the content of the file (with the first line being “[kubernetes]” and the last line ending in “…
…
Continue reading “How Do You Install Kubernetes on an AWS Instance of RedHat Linux?”
Updated on 10/13/20.
Problem scenario
You want to deploy a Kubernetes cluster in AWS. You have an Ubuntu server (e.g., with a nano flavor in AWS or a minimally powered Azure instance). It has no software packages installed on it (e.g., it does not have Docker or Kubernetes). How do you deploy Kubernetes in AWS?
Solution
Warning: This will automatically create EC2 servers in you AWS account behind the scenes.
…
Continue reading “How Do You Deploy a Kubernetes Cluster in AWS Using an Ubuntu Linux Instance?”
We found Docker Cookbook to be a good reference book about Docker. The author, via O’Reilly Customer Service, responded to us saying that on page 79 near the top of Figure 3-1, the open curly brace “{” should be removed. We were impressed the author took that the time to respond.
A shorter book written by two authors (neither of whom authored the Docker Cookbook) is called
…
Update on 11/20/20: We recommend you see How Do You Install the docker.service File on RHEL 8.x? instead of the directions below. (Many times this command will work: sudo yum -y install docker )
Update on 9/10/19: These directions below work to install Docker version 17.05.0-ce on RHEL 8.x.
These “directions” to install Docker on RedHat Enterprise Linux include a script and how to run it.
…
Continue reading “How To Install Docker on an AWS Instance of RedHat Linux”
Updated 12/26/18
Problem scenario
You want to install Docker. You can make changes to the Ubuntu Linux repositories so you can use apt-get to install it. How do you install Docker on an AWS EC-2 instance?
Solution
There is an alternative set of directions if you click on this link here (if you would prefer not to configure the apt-get repositories). These directions below to install Docker on Ubuntu Linux include a script and how to run it (but the script below will make a change to the repositories that the Linux server uses).
…
Continue reading “How To Install Docker on an AWS Instance of Ubuntu”
Question
What is TCP port 8080 typically used for?
Answer
Jenkins, Docker, NodeJS, Apache Ambari, Apache Marathon, Apache Tomcat, Amazon Web Services’ Elastic Load Balancer, JBoss Application Server, GitLab, M2MLogger (remote monitoring), InfoSphere BigInsights Console (IBM’s proprietary Hadoop and Spark solution), JasperReports (because of Apache Tomcat), remote management of physical routers, and enterprise network proxy services all commonly use port 8080.
In part, taken from Learning AWS,
…
Continue reading “What is TCP port 8080 typically used for?”
Problem scenario
You want to move copies of all the files in a given subdirectory (we’ll say /tmp/a/ for an example) on a Docker host to go into a Docker container.
Solution
From the server use the command “docker ps” to find the container ID. Now that you have the container ID, you can write a script to move copies of the files into the Docker container.
…
Continue reading “How Do You Copy Many Files from Your Linux Server into a Docker Container?”