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goctl docker
goctl kube

goctl docker

goctl docker can quickly generate a Dockerfile to help developers/operations and maintenance personnel speed up the deployment pace and reduce deployment complexity.

Prepare

docker install

Dockerfile note

Choose the simplest mirror: For example, alpine, the entire mirror is about 5M

Set mirror time zone

RUN apk add --no-cache tzdata
ENV TZ Asia/Shanghai

Multi-stage build

Otherwise, an executable file will be built in the first stage of construction to ensure that the build process is independent of the host
The second stage uses the output of the first stage as input to construct the final minimalist image

Dockerfile writing process

First install the goctl tool

$ GO111MODULE=on GOPROXY=https://goproxy.cn/,direct go get -u github.com/tal-tech/go-zero/tools/goctl

Create a hello service under the greet project
```
$ goctl api new hello
```

The file structure is as follows:

greet
├── go.mod
├── go.sum
└── service
    └── hello
        ├── Dockerfile
        ├── etc
        │   └── hello-api.yaml
        ├── hello.api
        ├── hello.go
        └── internal
            ├── config
            │   └── config.go
            ├── handler
            │   ├── hellohandler.go
            │   └── routes.go
            ├── logic
            │   └── hellologic.go
            ├── svc
            │   └── servicecontext.go
            └── types
                └── types.go

Generate a Dockerfile in the hello directory

$ goctl docker -go hello.go

Dockerfile:

  FROM golang:alpine AS builder
  LABEL stage=gobuilder
  ENV CGO_ENABLED 0
  ENV GOOS linux
  ENV GOPROXY https://goproxy.cn,direct
  WORKDIR /build/zero
  ADD go.mod .
  ADD go.sum .
  RUN go mod download
  COPY . .
  COPY service/hello/etc /app/etc
  RUN go build -ldflags="-s -w" -o /app/hello service/hello/hello.go
  FROM alpine
  RUN apk update --no-cache
  RUN apk add --no-cache ca-certificates
  RUN apk add --no-cache tzdata
  ENV TZ Asia/Shanghai
  WORKDIR /app
  COPY --from=builder /app/hello /app/hello
  COPY --from=builder /app/etc /app/etc
  CMD ["./hello", "-f", "etc/hello-api.yaml"]

To build mirror in the greet directory

$ docker build -t hello:v1 -f service/hello/Dockerfile .

View mirror

hello v1 5455f2eaea6b 7 minutes ago 18.1MB

It can be seen that the mirror size is about 18M.

Start service

$ docker run --rm -it -p 8888:8888 hello:v1

Test service

$ curl -i http://localhost:8888/from/you

HTTP/1.1 200 OK
Content-Type: application/json
Date: Thu, 10 Dec 2020 06:03:02 GMT
Content-Length: 14
{"message":""}

goctl docker summary

The goctl tool greatly simplifies the writing of Dockerfile files, provides best practices out of the box, and supports template customization.

goctl kube

goctl kube provides the function of quickly generating a k8s deployment file, which can speed up the deployment progress of developers/operations and maintenance personnel and reduce deployment complexity.

Have a trouble to write K8S deployment files?

K8S yaml has a lot of parameters, need to write and check?
How to set the number of retained rollback versions?
How to detect startup success, how to detect live?
How to allocate and limit resources?
How to set the time zone? Otherwise, the print log is GMT standard time
How to expose services for other services to call?
How to configure horizontal scaling based on CPU and memory usage?

First, you need to know that you have these knowledge points, and secondly, it is not easy to understand all these knowledge points, and again, it is still easy to make mistakes every time you write!

Create service image

For demonstration, here we take the redis:6-alpine image as an example.

完整 K8S Deployment file writing process

First install the goctl tool

$ GO111MODULE=on GOPROXY=https://goproxy.cn/,direct go get -u github.com/tal-tech/go-zero/tools/goctl

One-click generation of K8S deployment files

$ goctl kube deploy -name redis -namespace adhoc -image redis:6-alpine -o redis.yaml -port 6379

The generated yaml file is as follows:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: redis
  namespace: adhoc
  labels:
    app: redis
spec:
  replicas: 3
  revisionHistoryLimit: 5
  selector:
    matchLabels:
      app: redis
  template:
    metadata:
      labels:
        app: redis
    spec:
      containers:
      - name: redis
        image: redis:6-alpine
        lifecycle:
          preStop:
            exec:
              command: ["sh","-c","sleep 5"]
        ports:
        - containerPort: 6379
        readinessProbe:
          tcpSocket:
            port: 6379
          initialDelaySeconds: 5
          periodSeconds: 10
        livenessProbe:
          tcpSocket:
            port: 6379
          initialDelaySeconds: 15
          periodSeconds: 20
        resources:
          requests:
            cpu: 500m
            memory: 512Mi
          limits:
            cpu: 1000m
            memory: 1024Mi
        volumeMounts:
        - name: timezone
          mountPath: /etc/localtime
      volumes:
        - name: timezone
          hostPath:
            path: /usr/share/zoneinfo/Asia/Shanghai
---
apiVersion: v1
kind: Service
metadata:
  name: redis-svc
  namespace: adhoc
spec:
  ports:
    - port: 6379
  selector:
    app: redis
---
apiVersion: autoscaling/v2beta1
kind: HorizontalPodAutoscaler
metadata:
  name: redis-hpa-c
  namespace: adhoc
  labels:
    app: redis-hpa-c
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: redis
  minReplicas: 3
  maxReplicas: 10
  metrics:
  - type: Resource
    resource:
      name: cpu
      targetAverageUtilization: 80
---
apiVersion: autoscaling/v2beta1
kind: HorizontalPodAutoscaler
metadata:
  name: redis-hpa-m
  namespace: adhoc
  labels:
    app: redis-hpa-m
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: redis
  minReplicas: 3
  maxReplicas: 10
  metrics:
  - type: Resource
    resource:
      name: memory
      targetAverageUtilization: 80

Deploy the service, if the adhoc namespace does not exist, please create it through kubectl create namespace adhoc

$ kubectl apply -f redis.yaml
deployment.apps/redis created
service/redis-svc created
horizontalpodautoscaler.autoscaling/redis-hpa-c created
horizontalpodautoscaler.autoscaling/redis-hpa-m created

View service permission status

$ kubectl get all -n adhoc
NAME                         READY   STATUS    RESTARTS   AGE
pod/redis-585bc66876-5ph26   1/1     Running   0          6m5s
pod/redis-585bc66876-bfqxz   1/1     Running   0          6m5s
pod/redis-585bc66876-vvfc9   1/1     Running   0          6m5s
NAME                TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)    AGE
service/redis-svc   ClusterIP   172.24.15.8   <none>        6379/TCP   6m5s
NAME                    READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/redis   3/3     3            3           6m6s
NAME                               DESIRED   CURRENT   READY   AGE
replicaset.apps/redis-585bc66876   3         3         3       6m6s
NAME                                              REFERENCE          TARGETS   MINPODS   MAXPODS   REPLICAS   AGE
horizontalpodautoscaler.autoscaling/redis-hpa-c   Deployment/redis   0%/80%    3         10        3          6m6s
horizontalpodautoscaler.autoscaling/redis-hpa-m   Deployment/redis   0%/80%    3         10        3          6m6s

Test service

$ kubectl run -i --tty --rm cli --image=redis:6-alpine -n adhoc -- sh
/data # redis-cli -h redis-svc
redis-svc:6379> set go-zero great
OK
redis-svc:6379> get go-zero
"great"