A Technical I.T./DevOps Blog
Problem scenario
You are using a variable in Ansible. You want to attach a string to it to augment this variable. You can rename it so later in the playbook you can call this modified, augmented version of the variable.
You assign the variable like this:
foo: ” {{ bar }}”
You want foo to have an extra string (e.g., “/subdirectory/path/to”). What do you do?
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Continue reading “How Do You Prepend or Append to a Variable in Ansible?”
Problem scenario
You go to the SonarQube web UI to log in. You see nowhere to log in but no error either. What could be wrong?
Solution
Have your web browser accept cookies. If you block cookies and using Apache web server with SonarQube 7.x, you may experience this problem.
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Question
You have read about the Sonar Scanner. What is it exactly?
Answer
It is now called the SonarQube Scanner — not the Sonar Scanner. Source: https://docs.sonarqube.org/latest/
“The SonarQube Scanner is recommended as the default launcher to analyze a project with SonarQube.” This quote was taken from
https://docs.sonarqube.org/display/SCAN/Analyzing+with+SonarQube+Scanner.
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Question
You are using Kubernetes. You read about Nodes and Pods. What is the difference?
Answer
A Pod is a collection of one or more containers (e.g., Docker or rkt containers). A node is a server that is the home of one or more Pods.
“A Node is a worker machine in Kubernetes and may be either a virtual or a physical machine…” (taken from
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Continue reading “What Is the Difference between a Node and a Pod in Kubernetes?”
Problem scenario
You have an Nginx instance configured to be an HTTP load balancer (aka invisible landing page, pass-through distributor or reverse proxy). You want to analyze the inbound web traffic that your Nginx server is currently receiving. How do you find out how many active connections there are through the load balancer?
Solution
1. Modify the /etc/nginx/conf.d/default.conf file in the Nginx HTTP load balancer.
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Problem scenario
You want to create a rudimentary CI/CD pipeline (one that is simple and has no QA or automated testing of code). You want to trigger a deployment of code upon code being checked into a Git repository. You want to set up GitLab and Jenkins to be the main servers of this pipeline. You have two other servers; one is for developing code on and checking code into a Git repository and the other server is for receiving code once it is checked into GitLab.
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Continue reading “How Do You Set up a Basic CI/CD Pipeline with GitLab and Jenkins?”
Problem scenario
You want to create a Docker container. What do you do?
Solution
Prerequisites
This assumes you have installed Docker on your Linux server. If you have not, click the link below corresponding with your distribution of Linux:
CentOS/RHEL/Fedora
Debian/Ubuntu
SUSE
If you want to use a Dockerfile to build a Docker image,
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Problem scenario
You started the uninstallation of a plugin in Jenkins via the web UI. The plugin now says “Uninstallation pending” in the web UI. You changed your mind (or you accidentally initiated the process to remove the plugin by clicking the “Uninstall” button) about removing the plugin. What do you do to keep the plugin continuously installed in Jenkins?
Solution
Background
When you initiate the uninstallation of a plugin,
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Continue reading “How Do You Cancel the Uninstallation of a Jenkins Plugin?”
Problem scenario
You know that Amazon Aurora is compatible with either PostgreSQL or MySQL. While RDS supports these database types as well as Oracle and SQL Server, RDS does not offer all of the advantages that Aurora offers.
You have read about the benefits of Aurora a database PaaS or DBaaS. You want to deploy Amazon Aurora because it has numerous features for high availability, performance,
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Continue reading “How Do You Use Amazon Aurora to Try It Out?”
Problem scenario
You try to use start-dfs.sh or start-yarn.sh. You received this message: Permission denied (publickey,gssapi-keyex,gssapi-with-mic).
What do you do?
Solution
You need to be able to ssh into the node without any Hadoop components. To help you troubleshoot, consider the following items on the server that is causing the problem (e.g., the DataNode server, but it could be the NameNode server itself):
1.
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