imersao-azure.md

go build

./go-docker

OUTPUT: 2019/12/01 09:48:40 Starting Server

Test the application:

curl http://localhost:8080

OUTPUT: Hello, Guest

curl http://localhost:8080\?name=Andre

OUTPUT: Hello, Andre

Dockerfile

# Start from the latest golang base image
FROM golang:1.13.4-buster

# Add Maintainer Info
LABEL maintainer="Andre Almar <[email protected]>"

# Set the Current Working Directory inside the container
WORKDIR /app

# Copy go mod and sum files
COPY go.mod go.sum ./

# Download all dependencies. Dependencies will be cached if the go.mod and go.sum files are not changed
RUN go mod download

# Copy the source from the current directory to the Working Directory inside the container
COPY . .

# Build the Go app
RUN go build -o main .

# Expose port 8080 to the outside world
EXPOSE 8080

# Command to run the executable
CMD ["./main"]

Build the image:

docker build -t go-docker .

Run the Docker Image:

docker run -d -p 8080:8080 go-docker

See the container running:

docker container ls

Interact with the app inside the running container:

curl http://localhost:8080

OUTPUT: Hello, Guest

curl http://localhost:8080\?name=Andre

OUTPUT: Hello, Andre

MULTISTAGE BUILDING

Dockerfile Multistage

# Start from the latest golang base image
FROM golang:latest as builder

# Add Maintainer Info
LABEL maintainer="Andre Almar <[email protected]>"

# Set the Current Working Directory inside the container
WORKDIR /app

# Copy go mod and sum files
COPY go.mod go.sum ./

# Download all dependencies. Dependencies will be cached if the go.mod and go.sum files are not changed
RUN go mod download

# Copy the source from the current directory to the Working Directory inside the container
COPY . .

# Build the Go app
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o main .


######## Start a new stage from scratch #######
FROM alpine:latest  

RUN apk --no-cache add ca-certificates

WORKDIR /root/

# Copy the Pre-built binary file from the previous stage
COPY --from=builder /app/main .

# Expose port 8080 to the outside world
EXPOSE 8080

# Command to run the executable
CMD ["./main"]

Build the optimized Docker image:

docker build -t go-docker-optimized -f Dockerfile.multistage .

Check if the image is created:

docker images

REPOSITORY            TAG                 IMAGE ID            CREATED             SIZE
go-docker-optimized   latest              4ba2c8b851fe        7 seconds ago       14MB

Comparing the 2 images:

REPOSITORY            TAG                 IMAGE ID            CREATED             SIZE
go-docker-optimized   latest              4ba2c8b851fe        7 seconds ago       14MB
go-docker             latest              8be37dd67655        10 minutes ago      819MB

Now interact with the Optimized Docker image:

curl http://localhost:8080

OUTPUT: Hello, Guest

curl http://localhost:8080\?name=Andre

OUTPUT: Hello, Andre

Create your Kubernetes cluster (AKS)

Launch Cloud Shell

Then type the command below to create a resource group:

az group create --name myResourceGroup --location eastus

The output must be something like this:

{
  "id": "/subscriptions/<guid>/resourceGroups/myResourceGroup",
  "location": "eastus",
  "managedBy": null,
  "name": "myResourceGroup",
  "properties": {
    "provisioningState": "Succeeded"
  },
  "tags": null
}

Don't forget to register the following Subscription:

az provider register --namespace Microsoft.Network

Type the following command to create the AKS cluster:

az aks create --resource-group myResourceGroup --name myAKSCluster --node-count 1 --enable-addons monitoring --generate-ssh-keys

The following example creates a cluster named myAKSCluster with one node. Azure Monitor for containers is also enabled using the --enable-addons monitoring parameter. This will take several minutes to complete.

After a few minutes, the command completes and returns JSON-formatted information about the cluster.

Deploying our app on AKS

Type the following:

To create a namespace:

apiVersion: v1
kind: Namespace
metadata:
  name: imersao
  labels:
    name: imersao

and then

kubectl apply -f namespace.yaml

To create a deployment:

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: go-docker-app-deployment
  namespace: imersao
spec:
  replicas: 2
  template:
    metadata:
      labels:
        app: go-docker
    spec:
      containers:
        - name: go-docker
          image: andrealmar/go-docker-optimized:latest
          imagePullPolicy: Always
          resources:
            limits:
              cpu: 400m
              memory: 300Mi
            requests:
              cpu: 200m
              memory: 150Mi

and then

kubectl apply -f deployment.yaml

To create a service (to expose our deployment to external world)

apiVersion: v1
kind: Service
metadata:
  name: go-docker-service
  namespace: imersao
spec:
  type: LoadBalancer
  ports:
    - name: http
      protocol: TCP
      port: 8080
      targetPort: 8080
  selector:
    app: go-docker

and then

kubectl apply -f service.yaml

Check if the service was created:

kubectl get service go-docker-service -n imersao --watch

Wait a few minutes to get the EXTERNAL IP:

➜  kubernetes kubectl get service go-docker-service -n imersao --watch
NAME                TYPE           CLUSTER-IP    EXTERNAL-IP    PORT(S)          AGE
go-docker-service   LoadBalancer   10.0.67.193   20.42.32.175   8080:31702/TCP   2m24s

Now try to access the app (already deployed on AKS) from your browser:

http://20.42.32.175:8080/?name=Andre

OUTPUT: Hello, Andre

Now DELETE the cluster so you don't get charged ;)

az group delete --name myResourceGroup --yes --no-wait

references: https://docs.microsoft.com/en-us/azure/aks/kubernetes-walkthrough from zero to a bank in one year: https://www.starlingbank.com

andrealmar/imersao-azure.md