feat: Add Kubernetes resources for demo-app namespace, api-node servi…

…ce, api-golang service, client-react-nginx service, and strip-api-prefixes middleware

- Added Namespace.yaml for demo-app namespace
- Added Service.yaml for api-node service
- Added Service.yaml for api-golang service
- Added Service.yaml for client-react-nginx service
- Added Middleware.yaml for strip-api-prefixes middleware

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/kubernetes/demo-apps/go-node-react-postgres/Namespace.yaml

@@ -0,0 +1,4 @@
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: demo-app

docs/kubernetes/demo-apps/go-node-react-postgres/README.md

@@ -0,0 +1,165 @@
+## Multi Service App
+
+This is a simple multi-service app that consists of a React Client, a Node API, and a Golang API. The app uses a Postgresql database for data storage.
+
+### Prerequisites
+
+- Kubernetes Cluster
+- Helm v3
+- kubectl
+
+## Layout
+
+The following shows the layout of this directory:
+
+```markdown
+├── api-golang
+│   ├── Deployment.yaml
+│   ├── IngressRoute.yaml
+│   ├── Secret.yml
+│   └── Service.yaml
+├── api-node
+│   ├── Deployment.yaml
+│   ├── IngressRoute.yaml
+│   ├── Secret.yaml
+│   └── Service.yaml
+├── client-react
+│   ├── ConfigMap.yaml
+│   ├── Deployment.yaml
+│   ├── IngressRoute.yaml
+│   └── Service.yaml
+├── common
+│   ├── Middleware.yaml
+│   ├── Namespace.yaml
+└── postgresql
+    ├── Job.db-migrator.yaml
+    └── Secret.db-password.yaml
+```
+
+### Setting up the APP
+
+Make sure you are in `go-node-react-postgres` directory.
+
+1. Create a Namespace
+
+```bash
+kubectl apply -f Namespace.yaml
+```
+
+switch to the namespace:
+
+```bash
+kubectl config set-context --current --namespace=demo-app
+```
+
+2. Install Postgresql Database using Helm
+
+Add the bitnami repo:
+
+```bash
+helm repo add bitnami https://charts.bitnami.com/bitnami
+```
+
+Install the chart:
+
+```bash
+helm upgrade --install \
+    -n postgres \
+    postgres bitnami/postgresql \
+    --set auth.postgresPassword=foobarbaz \
+    --version 15.3.2 \
+    --values ./postgresql/values.yaml \
+    --create-namespace
+```
+
+3. Database Migration
+
+First we need to create a secret for the database password:
+
+```bash
+kubectl apply -f postgresql/Secret.db-password.yaml
+```
+
+Then we can run the migration job:
+
+```bash
+kubectl apply -f postgresql/Job.db-migrator.yaml
+```
+
+5. Install traffic Ingress Controller
+
+Add the traefik repo:
+
+```bash
+helm repo add traefik https://traefik.github.io/charts
+```
+
+Install the chart:
+
+```bash
+helm upgrade --install \
+    -n traefik \
+    traefik traefik/traefik \
+    --version 20.8.0 \
+    --create-namespace
+```
+
+6. Deploy a Middleware to Strop of the prefix from incoming requests
+
+```bash
+kubectl apply -f common/Middleware.yaml
+```
+
+7. Deploy the Golang API.
+
+Before deploying, update the `IngressRoute.yaml` file to match the correct host.
+
+```yaml
+routes:
+    - kind: Rule
+      match: Host(`host/domain`) && PathPrefix(`/api/golang`)
+```
+
+Then deploy the API:
+
+```bash
+kubectl apply -f api-golang
+```
+
+8. Deploy the Node API. 
+
+Before deploying, update the `IngressRoute.yaml` file to match the correct host.
+
+```yaml
+routes:
+    - kind: Rule
+      match: Host(`host/domain`) && PathPrefix(`/api/node`)
+```
+
+Then deploy the API:
+
+```bash
+kubectl apply -f api-node
+```
+
+9. Deploy the React Client.
+
+Before deploying, update the `IngressRoute.yaml` file to match the correct host.
+
+```yaml
+routes:
+    - kind: Rule
+      match: Host(`host/domain`) # This will root with no prefix
+```
+
+Then deploy the client:
+
+```bash
+kubectl apply -f client-react
+```
+
+Now you should be able to access the app using the host/domain you have set in the IngressRoute files.
+
+- For Node API, you can access it using `<host>/api/node`.
+- For Golang API, you can access it using `<host>/api/golang`.
+- For React Client, you can access it using `<host>`.

docs/kubernetes/demo-apps/go-node-react-postgres/api-golang/Deployment.yaml

@@ -0,0 +1,45 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: api-golang
+  namespace: demo-app
+  labels:
+    app: api-golang
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: api-golang
+  template:
+    metadata:
+      labels:
+        app: api-golang
+    spec:
+      containers:
+        - name: api-golang
+          image: sidpalas/devops-directive-docker-course-api-golang:foobarbaz
+          env:
+            - name: PORT
+              value: "8000"
+          envFrom:
+            - secretRef:
+                name: api-golang-database-url
+          ports:
+            - containerPort: 8000
+              protocol: TCP
+          readinessProbe:
+            httpGet:
+              path: /ping
+              port: 8000
+          resources:
+            limits:
+              memory: "100Mi"
+            requests:
+              memory: "100Mi"
+              cpu: "50m"
+          securityContext:
+            allowPrivilegeEscalation: false
+            privileged: false
+      securityContext:
+        seccompProfile:
+          type: RuntimeDefault

docs/kubernetes/demo-apps/go-node-react-postgres/api-golang/IngressRoute.yaml

@@ -0,0 +1,18 @@
+apiVersion: traefik.containo.us/v1alpha1
+kind: IngressRoute
+metadata:
+  name: api-golang
+  namespace: demo-app
+spec:
+  entryPoints:
+    - web
+  routes:
+    - kind: Rule
+      match: Host(`d11ae95f-7695-4635-9637-13829bf55c83.lb.civo.com`) && PathPrefix(`/api/golang`)
+      middlewares:
+        - name: strip-api-prefixes
+      services:
+        - kind: Service
+          name: api-golang
+          port: 8000
+          scheme: http

docs/kubernetes/demo-apps/go-node-react-postgres/api-golang/Secret.yml

@@ -0,0 +1,9 @@
+# ⛔️ DONT PUT SECRET FILES IN VCS
+apiVersion: v1
+kind: Secret
+type: Opaque
+metadata:
+  name: api-golang-database-url
+  namespace: demo-app
+stringData:
+  DATABASE_URL: postgres://postgres:[email protected]:5432/postgres

docs/kubernetes/demo-apps/go-node-react-postgres/api-golang/Service.yaml

@@ -0,0 +1,12 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: api-golang
+  namespace: demo-app
+spec:
+  selector:
+    app: api-golang
+  ports:
+    - protocol: TCP
+      port: 8000
+      targetPort: 8000

docs/kubernetes/demo-apps/go-node-react-postgres/api-node/Deployment.yaml

@@ -0,0 +1,45 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: api-node
+  namespace: demo-app
+  labels:
+    app: api-node
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: api-node
+  template:
+    metadata:
+      labels:
+        app: api-node
+    spec:
+      containers:
+        - name: api-node
+          image: sidpalas/devops-directive-docker-course-api-node:foobarbaz
+          env:
+            - name: PORT
+              value: "3000"
+          envFrom:
+            - secretRef:
+                name: api-node-database-url
+          ports:
+            - containerPort: 3000
+              protocol: TCP
+          readinessProbe:
+            httpGet:
+              path: /ping
+              port: 3000
+          resources:
+            limits:
+              memory: "100Mi"
+            requests:
+              memory: "100Mi"
+              cpu: "50m"
+          securityContext:
+            allowPrivilegeEscalation: false
+            privileged: false
+      securityContext:
+        seccompProfile:
+          type: RuntimeDefault

docs/kubernetes/demo-apps/go-node-react-postgres/api-node/IngressRoute.yaml

@@ -0,0 +1,18 @@
+apiVersion: traefik.containo.us/v1alpha1
+kind: IngressRoute
+metadata:
+  name: api-node
+  namespace: demo-app
+spec:
+  entryPoints:
+    - web
+  routes:
+    - kind: Rule
+      match: Host(`d11ae95f-7695-4635-9637-13829bf55c83.lb.civo.com`) && PathPrefix(`/api/node`)
+      middlewares:
+        - name: strip-api-prefixes
+      services:
+        - kind: Service
+          name: api-node
+          port: 3000
+          scheme: http

docs/kubernetes/demo-apps/go-node-react-postgres/api-node/Secret.yaml

@@ -0,0 +1,9 @@
+# ⛔️ DONT PUT SECRET FILES IN VCS
+apiVersion: v1
+kind: Secret
+type: Opaque
+metadata:
+  name: api-node-database-url
+  namespace: demo-app
+stringData:
+  DATABASE_URL: postgres://postgres:[email protected]:5432/postgres

docs/kubernetes/demo-apps/go-node-react-postgres/api-node/Service.yaml

@@ -0,0 +1,12 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: api-node
+  namespace: demo-app
+spec:
+  selector:
+    app: api-node
+  ports:
+    - protocol: TCP
+      port: 3000
+      targetPort: 3000