Merge pull request #6 from google/add_minikube

Add minikube examples

.github/dependabot.yml

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+---
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/" 
+    schedule:
+        interval: "monthly"

.github/workflows/build.yaml

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+name: build
+on:
+  workflow_dispatch:
+  push:
+  pull_request:
+  schedule:
+    # every day at 6am & 6pm pacific
+    - cron: "0 1,13 * * *"
+jobs:
+  build:
+    strategy:
+      matrix:
+          os: [ubuntu-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab
+      - uses: azure/setup-kubectl@901a10e89ea615cf61f57ac05cecdf23e7de06d8
+      - uses: medyagh/setup-minikube@latest
+      - name: install tools for mac os
+        if: matrix.os == 'macos-12'
+        shell: bash
+        run: |
+          brew install docker-machine docker
+          sudo docker --version
+          sysctl hw.physicalcpu hw.logicalcpu 
+          sudo /usr/libexec/ApplicationFirewall/socketfilterfw --setglobalstate off
+          sudo /usr/libexec/ApplicationFirewall/socketfilterfw -k
+
+      - name: Build Docker images inside minikube
+        run: | 
+          eval $(minikube docker-env)
+          cd minikube
+          docker build -t local/devex:v1 .
+      - name: Deploy to to Kubernetes 
+        run: | 
+          kubectl apply -f minikube/deploy/k8s.yaml 
+      - name: Verify Deployment
+        run: | 
+          minikube service list
+          minikube service local-devex-svc --url --wait=10
+          kubectl get pods -A
+          kubectl wait --for=condition=ready pod -l app=local-devex
+          curl -vvv $(minikube service local-devex-svc --url)

minikube/.gitignore

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+local-dev-example-with-minikube
+.DS_Store

minikube/Dockerfile

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+FROM golang:alpine
+
+# Set the Current Working Directory inside the container
+WORKDIR $GOPATH/src/github.com/medyagh/local-dev-example-with-minikube/
+
+# Copy everything from the current directory to the PWD (Present Working Directory) inside the container
+COPY . .
+
+# Install the package
+RUN go install -v ./...
+
+# This container exposes port 8080 to the outside world
+EXPOSE 8080
+
+# Run the executable
+CMD ["local-dev-example-with-minikube"]

minikube/README.md

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+# local-dev-example-with-minikube
+
+
+This repo demos a simple go app being deployed to a Kubernetes cluster using minikube, and demonstrates changing the code and re-deploying a new version.
+
+
+## Requirements
+- Clone this repo!
+- Install [minikube](https://minikube.sigs.k8s.io/docs/start/)
+- Install [Docker CLI](https://minikube.sigs.k8s.io/docs/tutorials/docker_desktop_replacement/) (Docker Desktop is not required, Docker CLI is sufficent)
+
+
+## Build and deploy the app to minikube for the first time!
+
+1. Start minikube
+    ```console
+    minikube start
+    ```
+
+2. Point your terminal to minikube's Docker using `minikube docker-env`
+    ```console
+    # on Mac or Linux
+    eval $(minikube docker-env)
+    ```
+
+    ```console
+    # on Windows PowerShell
+    & minikube docker-env | Invoke-Expression
+    ```
+
+    Tip 1: if you close your terminal you will have to re-point your docker-env.
+
+    Tip 2: to verify that your terminal is pointing to minikube's Docker you can run `minikube status` and it will show "docker-env: in-use"
+
+4. Build Docker image inside minikube
+
+    ```console
+    docker build -t local/devex:v1 .
+    ```
+4. Deploy to Kubernetes
+    ```console
+    kubectl apply -f deploy/k8s.yaml
+    ```
+5. Accees the deployed service in your browser
+    ```console
+    minikube service local-devex-svc
+    ```
+    Tip: you can try `$ minikube service list` to see all exposed serivces.
+
+
+## Iterative development (how to redeploy after a code change)
+
+1. Make a change in the code (for example bump the version in `main.go`)
+2. Ensure you're still pointing to minikube's Docker using `minikube docker-env`)
+3. Delete the deployment and the image
+    ```console
+    kubectl delete -f deploy/k8s.yaml
+    docker rmi local/devex:v1
+    ```
+4. Rebuild the image and re-deploy to Kubernetes
+    ```console
+    docker build -t local/devex:v1 .
+    kubectl apply -f deploy/k8s.yaml
+    ```
+5. Access the deployed service in your browser
+    ```console
+    minikube service local-devex-svc
+    ```
+
+(for faster development you can combine steps 3 and 4 the commands in one)
+```
+kubectl delete -f deploy/k8s.yaml;docker rmi local/devex:v1;docker build -t local/devex:v1 .;kubectl apply -f deploy/k8s.yaml
+```
+
+
+### Mount Files to minikube (persistent storage example)
+ 
+- let's create a example file on our workstation (laptop) to share with our deployment in minikube
+```console
+mkdir -p ~/Desktop/local-devex
+echo "Hello from laptop" > ~/Desktop/local-devex/hello-world.text
+```
+
+in a separate window run:
+```console
+ minikube mount ~/Desktop/local-devex:/data/
+```

minikube/deploy/k8s.yaml

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+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: local-devex-deploy
+  labels:
+    app: local-devex
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: local-devex
+  template:
+    metadata:
+      labels:
+        app: local-devex
+    spec:
+      containers:
+      - name: app
+        image: local/devex:v1
+        ports:
+        - containerPort: 8080
+        volumeMounts:
+        - mountPath: /data
+          name: test-volume
+      volumes:
+        - name: test-volume
+          hostPath:
+            # directory location on host
+            path: /data
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: local-devex-svc
+spec:
+  type: NodePort
+  selector:
+    app: local-devex
+  ports:
+  - name: local-devex-port
+    protocol: TCP
+    port: 8080
+    targetPort: 8080

minikube/go.mod

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+module local-dev-example-with-minikube
+
+go 1.19

minikube/k8s.yaml

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+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: local-devex-deploy
+  labels:
+    app: local-devex
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: local-devex
+  template:
+    metadata:
+      labels:
+        app: local-devex
+    spec:
+      containers:
+      - name: app
+        image: local/devex:v1
+        ports:
+        - containerPort: 8080
+        volumeMounts:
+        - mountPath: /data
+          name: test-volume
+      volumes:
+        - name: test-volume
+          hostPath:
+            # directory location on host
+            path: /data
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: local-devex-svc
+spec:
+  type: NodePort
+  selector:
+    app: local-devex
+  ports:
+  - name: local-devex-port
+    protocol: TCP
+    port: 8080
+    targetPort: 8080

minikube/main.go

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+package main
+
+import (
+	"fmt"
+	"net/http"
+	"os"
+	"time"
+)
+
+var version = "0.0.2"
+
+func indexHandler(w http.ResponseWriter, req *http.Request) {
+	localFile, err := os.ReadFile("/data/hello-world.txt")
+	if err != nil {
+		fmt.Printf("couldn't read file %v\n", err)
+
+	}
+	fmt.Fprintf(w, "<h1>hello world :) </h1> \n Version %s\n File Content:%s", version, localFile)
+}
+
+func headersHandler(w http.ResponseWriter, req *http.Request) {
+
+	for name, headers := range req.Header {
+		for _, h := range headers {
+			fmt.Fprintf(w, "%v: %v\n", name, h)
+		}
+	}
+}
+
+func main() {
+
+	http.HandleFunc("/", indexHandler)
+	http.HandleFunc("/headers", headersHandler)
+
+	welcomeText := fmt.Sprintf("%s Starting example version %s, Listening on port 8080 ...", time.Now().String(), version)
+	fmt.Println(welcomeText)
+	http.ListenAndServe(":8080", nil)
+}