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 <andre@y7mail.com>"
# 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 <andre@y7mail.com>"
# 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