DEV Community: onieio

HTML Basics: Essential Tags

onieio — Thu, 07 Dec 2023 01:26:14 +0000

HTML (Hypertext Markup Language) is the standard language for creating and designing web pages. It uses various tags to structure content and define elements on a webpage. Here are some fundamental HTML tags that every web developer should know:

<!DOCTYPE html> This declaration specifies the HTML version being used. It should be placed at the very beginning of an HTML document.

<!DOCTYPE html>

<html> The root element of an HTML document.

<html>
  <!-- Content goes here -->
</html>

<head> Contains meta-information about the HTML document, such as title, character set, and linked stylesheets.

<head>
  <title>Document Title</title>
  <!-- Other metadata goes here -->
</head>

<body> Encloses the content of the HTML document, including text, images, links, and more.

<body>
  <h1>Hello, World!</h1>
  <p>This is a sample paragraph.</p>
  <!-- Other content goes here -->
</body>

<h1> to <h6> Heading tags, ranging from the largest <h1> to the smallest <h6>.

<h1>Heading 1</h1>
<h2>Heading 2</h2>
<!-- ... -->
<h6>Heading 6</h6>

<p> Defines a paragraph.

<p>This is a paragraph.</p>

<a> Creates hyperlinks to navigate to other pages or resources.

<a href="https://www.example.com">Visit Example.com</a>

<img> Embeds images in the document.

<img src="image.jpg" alt="Description of the image">

<ul>, <ol>, <li> Defines unordered and ordered lists with list items.

Unordered List:

<ul>
  <li>Item 1</li>
  <li>Item 2</li>
</ul>

Ordered List:

<ol>
  <li>Item 1</li>
  <li>Item 2</li>
</ol>

<div> A generic container that does not carry any semantic meaning.

<div>
  <!-- Content goes here -->
</div>

<span> Similar to <div>, but used for inline elements.

<p>This is <span style="color: red;">red</span> text.</p>

<br> Creates a line break within text.

<p>This is the first line.<br>This is the second line.</p>

<hr> Represents a thematic break or horizontal rule.

<hr>

These are just a few of the essential HTML tags. As you continue learning, you'll discover more tags and attributes to enhance the structure and presentation of your web pages.

Kubernetes Basics: Understanding Key Resources

onieio — Wed, 06 Dec 2023 16:33:35 +0000

Static Pods

Overview:
Static pods are Kubernetes pods that are managed directly by the kubelet on a node. They are not part of the Kubernetes control plane, making them suitable for running system-level daemons or essential services on individual nodes.

Usage:

Create a Static Pod:

Write a pod manifest file.
Place the file in the kubelet's specified directory (e.g., /etc/kubernetes/manifests).
Restart the kubelet to start the static pod.

sudo systemctl restart kubelet

Check the status of the static pod using kubectl or kubelet logs.

kubectl get pods
kubectl describe pod my-static-pod

Cleanup:

Delete the manifest file and restart the kubelet.

sudo rm /etc/kubernetes/manifests/my-static-pod.yaml
sudo systemctl restart kubelet

Pods

Overview:
Pods are the smallest deployable units in Kubernetes. They represent one or more containers that share storage, network, and specifications.

Usage:

Create a Pod:

Write a pod manifest file (YAML) defining containers, volumes, and metadata.
Apply the manifest using kubectl.

kubectl apply -f my-pod.yaml

Monitor Pod:

Check the status of the pod.

kubectl get pods
kubectl describe pod my-pod

Update Pod:

Modify the manifest file and apply the changes.

kubectl apply -f my-updated-pod.yaml

Deployments

Overview:
Deployments provide a declarative way to manage pod replicas, enabling easy updates and rollbacks.

Usage:

Create a Deployment:

Write a deployment manifest file specifying the desired state.
Apply the manifest using kubectl.

kubectl apply -f my-deployment.yaml

Scale Deployment:

Update the replica count in the deployment manifest.

kubectl scale deployment my-deployment --replicas=3

Update Deployment:

Modify the container image or other specifications in the deployment manifest.

kubectl apply -f my-updated-deployment.yaml

StatefulSets

Overview:
StatefulSets manage the deployment and scaling of stateful applications, maintaining stable network identities and storage.

Usage:
Create a StatefulSet:

Write a StatefulSet manifest file specifying pod templates and persistent volume claims.
Apply the manifest using kubectl.

kubectl apply -f my-statefulset.yaml

Scale StatefulSet:

Update the replica count in the StatefulSet manifest.

kubectl scale statefulset my-statefulset --replicas=3

Update StatefulSet:

Modify the pod template or other specifications in the StatefulSet manifest.

kubectl apply -f my-updated-statefulset.yaml

DaemonSets

Overview:
DaemonSets ensure that a copy of a pod runs on every node in the cluster, typically for system daemons or logging agents.

Usage:

Create a DaemonSet:

Write a DaemonSet manifest file specifying pod templates.
Apply the manifest using kubectl.

kubectl apply -f my-daemonset.yaml

Update DaemonSet:

Modify the pod template or other specifications in the DaemonSet manifest.

kubectl apply -f my-updated-daemonset.yaml

Monitor DaemonSet:

Check the status of the DaemonSet and the pods on each node.

kubectl get daemonset
kubectl get pods -l app=my-daemon

This document provides a basic understanding of key Kubernetes resources and commands, including static pods, pods, deployments, StatefulSets, and DaemonSets. Each section includes an overview, usage examples, and common operations.

GO Cheatsheet

onieio — Mon, 11 Jul 2022 06:48:14 +0000

defer

Prints the content at the end of the call.
defer fmt.Println("End of the statement")