Why is Docker Popular with Jenkins?

Question
You have noticed that Docker and Jenkins are regularly used together. Why is this?

Answer
1. The docker build command produces one artifact. Jenkins lends itself to well-defined tasks.

2. The logic and dependencies of the build can usually be completely contained in the Dockerfile (page 20 of Docker Up and Running). Simple lines of text can standardize many aspects of a given build (e.g.,

How Do You Install Spring Framework with Docker?

Problem scenario
You want to deploy the Spring framework with Docker. How do you do this?

Solution
Warning: The last step in this is not a security “recommended practice.” Only follow these directions (with sudo docker run…), if the server is not that important or you are in a very secure network. One published book says you can use “sudo docker …” as long as the server is not in production (page 43 of Docker Up and Running).

How Do You Troubleshoot the AWS Error “could not get token: NoCredentialProviders: no valid providers in chain. Deprecated.”?

Problem scenario
You run this command: kubectl get svc

You receive this:
” could not get token: NoCredentialProviders: no valid providers in chain. Deprecated.
For verbose messaging see aws.Config.CredentialsChainVerboseErrors”

What should you do?

Solution
Install and configure the AWS CLI. If you need assistance with this, see this posting.

What is a Service, a Deployment, an HPA, a Pod, an Ingress, a Secret, and a Node in Kubernetes?

Question
In Kubernetes you have heard of these things: service, deployment, HPA, pod, ingress, secret, configmap, and node. What are they?

Answer
Click on the relevant question for its answer:
What is a Secret in Kubernetes?
What is a ConfigMap in Kubernetes?
What is a Deployment in Kubernetes?
What is an Ingress Resource in Kubernetes?

How Do You Deploy AKS (Azure’s Kubernetes) Using the GUI?

Problem scenario
You want to use Azure’s Kubernetes PaaS offering using the GUI. What do you do?

Solution

1. Sign into the Azure portal.
2. Click on “Services” on the left.
3. Click on “Containers”.
4. Click on “Kubernetes services”.
5. Click “Add”.
6. Fill out the required fields.
7. Click the “Review + create” button.

What is a ConfigMap in Kubernetes?

Question
What is a ConfigMap in Kubernetes?

Answer
A ConfigMap is a mapping of configuration originally in YAML format that resides in etcd (partially taken from this external posting). A .yaml file will define the version of the Kubernetes API (e.g., version 1), data, and the “kind:” key will be set to “ConfigMap”.

The content of the ConfigMap is consumed by an application in Kubernetes.

What is an HPA in Kubernetes?

Question
What is an HPA in Kubernetes?

Answer
HPA stands for HorizontalPodAutoscaler. It is a concept and resource that allows clusters to scale out upon a certain condition being met. HPA can support a pod to scale based on certain amounts of CPU utilization. It natively supports granular CPU requests down to a single millicore. A .yaml file in Kubernetes has the key “kind”;

How Do You Use the Docker Pipeline Plugin with Jenkins?

Problem scenario
You want to use the Docker Pipline (with the Jenkins ID of “docker-workflow”). What do you do?

Solution
Prerequisites
Jenkins needs to be installed. If you need assistance, see this posting if you are using a CentOS/RHEL/Fedora server; if you want to install Jenkins on a Debian/Ubuntu server, see this posting.