docs: Refactor k8s (#97)

docs/argocd/manifests/declarative.yml

@@ -18,4 +18,5 @@ spec:
             selfHeal: true
         syncOptions:
         - CreateNamespace=true # This will create namespace if not present
+
 

docs/docker/introduction.md

@@ -38,11 +38,20 @@ Docker is an open-source platform designed to simplify the development, deployme
 - `CMD` (command to run when the container starts) 
 - `WORKDIR` (create a directory where all the files will be copied and used)
 
-To build an image from the **Dockerfile**, use this command:
+### Docker Build Architecture
+
+We can build the image in two ways single architecture or multi-architecture. In the single architecture, we can build the image for a specific architecture, and in multi-architecture, we can build the image for multiple architectures.
+
+#### Single Architecture
+
+```bash
+docker build -t <image-name> .
+```
+
+#### Multi-Architecture
 
 ```bash
-docker build <path> 
-// docker build .
+docker buildx build --platform linux/amd64,linux/arm64 -t <image-name> .
 ```
 
 **Good Practice**
@@ -236,6 +245,18 @@ HEALTHCHECK --interval=30s --timeout=3s \
 CMD curl -f http://localhost/ || exit 1
 ```
 
+### Container Registry
+
+A repo - a collection of repositories. Use to store and access container images.
+
+Some popular registries are:
+
+- Docker Hub
+- GitHub Container Registry (ghcr.io)
+- Google Container Registry (gcr.io)
+- Amazon Elastic Container Registry (ECR)
+- Azure Container Registry (ACR) 
+
 ### Private Docker Registry
 
 We can create a registry with the official [Registry image](https://hub.docker.com/_/registry).

docs/github-actions/introduction.md

@@ -233,6 +233,45 @@ jobs:
           run: echo ${{ needs.deploy.outputs.url }}
 ```
 
+## Artifacts
+
+It allows you to share data between jobs in a workflow and store data once the workflow has been completed. We can use the `upload-artifact` and `download-artifact` actions to upload and download artifacts.
+
+```yaml
+name: Share data between jobs
+
+on: [push]
+
+jobs:
+  job_1:
+    name: Generate Random Number
+    runs-on: ubuntu-latest
+    steps:
+      - shell: bash
+        run: |
+          echo $((RANDOM % 100)) > random-number.txt
+      - name: Upload random number for job 1
+        uses: actions/upload-artifact@v4
+        with:
+          name: random_number
+          path: random-number.txt
+
+  job_2:
+    name: Echo Random Number
+    needs: job_1
+    runs-on: ubuntu-latest
+    steps:
+      - name: Download random number from job 1
+        uses: actions/download-artifact@v4
+        with:
+          name: random_number
+      - shell: bash
+        run: |
+          number=$(cat random-number.txt)
+          echo The random number is $number
+``` 
+
+
 ### What's next?
 
 - [Scenarios](./scenarios.md) - A collection of GitHub Actions workflow files I use and created to help you understand the concepts better.

docs/golang/concepts/0) test.go

@@ -1 +1,15 @@
-package main
+package main
+
+import "fmt"
+
+func main() {
+	var num int = 42
+	var numFloat float64 = float64(num)
+
+	var numFloat2 = 3.14
+	var numInt = int(numFloat2)
+
+	fmt.Println(numFloat)
+	fmt.Println(numInt)
+}
+

docs/golang/concepts/17) switch-statements.go

@@ -2,13 +2,14 @@ package main
 
 func main() {
 
-	city := "london"
+	city := "paris"
 
 	switch city {
 	case "london", "manchester": // Here we are checking for multiple values with the same output
 		println("London or Manchester")
 	case "paris":
 		println("Paris ")
+		fallthrough
 	case "rome":
 		println("Rome ")
 	default: // This is the default case

docs/golang/concepts/6) string-opr.go

@@ -0,0 +1,18 @@
+package main
+
+import (
+	"fmt"
+	"strings"
+)
+
+func main() {
+
+	var name = "John"
+	fmt.Println(len(name))               // It will print the length of the string
+	fmt.Println(strings.ToUpper(name))   // It will print the string in uppercase
+	fmt.Println(strings.ToLower(name))   // It will print the string in lowercase
+	fmt.Println(strings.Title(name))     // It will print the string in title case
+	fmt.Println(strings.Repeat(name, 3)) // It will repeat the string 3 times
+	fmt.Println(strings.Replace(name, "J", "K", 1)) // It will replace the first occurrence of J with K
+	fmt.Println(strings.Split(name, "")) // It will split the string into a slice of characters
+}

docs/helm/charts/minimal/.helmignore

@@ -0,0 +1,23 @@
+# Patterns to ignore when building packages.
+# This supports shell glob matching, relative path matching, and
+# negation (prefixed with !). Only one pattern per line.
+.DS_Store
+# Common VCS dirs
+.git/
+.gitignore
+.bzr/
+.bzrignore
+.hg/
+.hgignore
+.svn/
+# Common backup files
+*.swp
+*.bak
+*.tmp
+*.orig
+*~
+# Various IDEs
+.project
+.idea/
+*.tmproj
+.vscode/

docs/helm/charts/minimal/Chart.yaml

@@ -0,0 +1,6 @@
+apiVersion: v2
+name: minimal
+description: A tiny helm chart for educational purposes
+type: application
+version: 0.1.0
+appVersion: 1.26.0

docs/helm/charts/minimal/templates/NOTES.txt

@@ -0,0 +1 @@
+Hi 👋 -- you just deployed {{ template "envShort" . }} 

docs/helm/charts/minimal/templates/_helpers.tpl

@@ -0,0 +1,7 @@
+{{- define "envShort" -}}
+{{- if eq .Values.environment "production" -}}
+prod
+{{- else -}}
+non-prod
+{{- end -}}
+{{- end -}}

docs/helm/charts/minimal/templates/configmap.yaml

@@ -0,0 +1,13 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: helm-{{ .Release.Name }}-configmap
+data:
+  appVersion: {{ .Chart.AppVersion }}
+  environment: {{ .Values.environment | quote }}
+  envShort: {{ template "envShort" . }} 
+  {{- range .Values.configData }}
+  {{- if .enabled }}
+  {{ .key }}: {{ .value | quote }}
+  {{- end }}
+  {{- end }}

docs/helm/charts/minimal/values-alt.yaml

@@ -0,0 +1,6 @@
+environment: staging
+
+configData:
+  - key: conditionalKey
+    value: "this wont be included"
+    enabled: false

docs/helm/charts/minimal/values.yaml

@@ -0,0 +1,6 @@
+environment: production
+
+configData:
+  - key: conditionalKey
+    value: "this will be included"
+    enabled: true

docs/helm/introduction.md

@@ -3,31 +3,128 @@ sidebar_position: 1
 title: Helm Introduction
 ---
 
-Helm is Package manager for Kubernetes.
+Helm is package manager and a templating engine for Kubernetes. It allows you to define, install, and upgrade even the most complex Kubernetes applications. It's like apt, yum, or homebrew for Kubernetes. Primary use case is application deployment and environment management. 
+
+## Helm Architecture
+
+The new architecture of Helm 3 is very simple. It has only client-side components. The server-side components like Tiller are removed in Helm 3. Helm 3 is a client-side application that interacts with the Kubernetes API server.
 
 ### Using a Helm Chart
 
-- Once we install the helm to the system, we have to add a chart repository, like prometheus, Ingress-nginx and [more](https://artifacthub.io/packages/search?kind=0)
+To deploy an application using Helm, you need to create a Helm chart. A Helm chart is a collection of files that describe a related set of Kubernetes resources. A single chart might be used to deploy something simple, like a memcached pod, or something complex, like a full web app stack with HTTP servers, databases, caches, and so on.
+
+First we need to add the repository to the helm
+
+```bash
+helm repo add bitnami https://charts.bitnami.com/bitnami
+```
+
+- We can update the repository using the following command
+
+```bash
+helm repo update
+```
 
-Eg:
+- Then we can install the chart using the following command
 
 ```bash
-helm repo add <name> <repo url>
-helm repo add kubernetes-dashboard https://kubernetes.github.io/dashboard/
+helm install postgres bitnami/postgresql
 ```
 
-- To check list of charts we can install
+we can search for the available charts using the following command
 
 ```bash
-helm search repo kubernetes-dashboard
+helm search repo bitnami
 ```
 
-- To install a chart 
+Or search the available versions of the chart using the following command
 
+```bash
+helm search repo bitnami/postgresql --versions
 ```
-helm install <name> kubernetes-dashboard/kubernetes-dashboard
+
+We can also pull the chart locally to look at the configuration files. `--version` flag is used to specify the version of the chart not the app version
+
+```bash
+helm pull bitnami/postgresql --version 16.3.0
 ```
 
+We can give values to the chart using the values flag and padding the values in the yaml file
+
+```bash
+helm install postgresql bitnami/postgresql --values values.yaml
+```
+
+The values.yaml file should look like this
+
+```yaml
+commonAnnotations:
+    foo: bar
+```
+
+We can upgrade the chart using the following command
+
+```bash
+helm upgrade --install postgresql bitnami/postgresql --values values.yaml --version=16.4.0 --namespace=my-namespace
+```
+
+We can rollback the chart using the following command `postgresql` is the release name we can get the release name using `helm list`.
+
+```bash
+helm rollback postgresql
+```
+
+To check helm release status
+
+```bash
+helm list
+```
+
+To check values provided by the user. Again `postgresql` is the release name
+
+```bash
+helm get values postgresql
+```
+
+We can also get actual manifest files that are generated by the helm chart. Again `postgresql` is the release name
+
+```bash
+helm get manifest postgresql
+```
+
+We can uninstall the chart using the following command. Again `postgresql` is the release name
+
+```bash
+helm uninstall postgresql
+```
+
+### Creating our own Helm Chart
+
+- We can create our own helm chart using the following command. It will generate a dir with all the boilerplate code.
+
+```bash
+helm create mychart
+```
+
+- We can install the chart using the following command. `mychart` is the chart name and `./mychart` is the path to the chart
+
+```bash
+helm install mychart ./mychart
+```
+
+We can also apply with a values file
+
+```bash
+helm install mychart ./mychart --values values.yaml
+```
+
+## Helm Hooks
+
+Helm hooks are a way to interact with the lifecycle of a release. They allow you to intervene at certain points in a release's life cycle. Helm supports the following hooks:
+
+- `pre-install` - Runs before any templates are rendered.
+- `post-install` - Runs after all templates have been rendered and resources have been created.
+
 ### What's next?
 
 [Learning Resources](./learning-resources.md) - Learn more about Helm with these resources.

docs/kubernetes/apps/nginx-simple-app/Deployment.yaml

@@ -0,0 +1,26 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: nginx-deployment
+  namespace: nginx-ns
+spec:
+  selector:
+    matchLabels:
+      app: nginx-app
+  template:
+    metadata:
+      labels:
+        app: nginx-app
+    spec:
+      containers:
+      - name: nginx
+        image: nginx:latest
+        resources:
+          limits:
+            memory: "128Mi"
+            cpu: "500m"
+          requests:
+            memory: "64Mi"
+            cpu: "250m"
+        ports:
+        - containerPort: 80

docs/kubernetes/apps/nginx-simple-app/Namespace.yaml

@@ -0,0 +1,4 @@
+apiVersion: v1 
+kind: Namespace
+metadata:
+  name: nginx-ns