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Personal Single Server Microservices Practice

Building Microservices with etcd and go-zero

Preface

  • Although I started working with microservices last year and deployed them on my personal server, they were all using direct connection mode. Today I took the opportunity to upgrade the go-zero codebase and revamp the architecture.

Framework

  • I continued using go-zero (https://github.com/zeromicro/go-zero) which was originally adopted last year, just updating to the latest version.

  • The code structure features a double-layer service under the root app directory, with shared code in pkg (e.g., configuration center access) and a common Dockerfile for all services.

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  • The Dockerfile uses multi-stage builds. The build argument SERVICE_PATH specifies the target service:

    • docker build -t xxx:xx --build-arg SERVICE_PATH=${SERVICE_PATH} .
FROM golang:alpine3.18 AS builder

LABEL stage=gobuilder

ARG SERVICE_PATH
ENV CGO_ENABLED 0

RUN echo -e 'https://mirrors.aliyun.com/alpine/v3.18/main/\nhttps://mirrors.aliyun.com/alpine/v3.18/community/' > /etc/apk/repositories && apk update --no-cache && apk add --no-cache tzdata

WORKDIR /build

COPY . .
RUN go env -w GO111MODULE=on
RUN go env -w GOPROXY=https://mirrors.aliyun.com/goproxy/,direct
RUN go mod download
RUN go build -ldflags="-s -w" -o /build/main /build/app/${SERVICE_PATH}

FROM scratch

ARG SERVICE_PATH

COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
COPY --from=builder /usr/share/zoneinfo/Asia/Shanghai /usr/share/zoneinfo/Asia/Shanghai
ENV TZ Asia/Shanghai

WORKDIR /app
COPY --from=builder /build/main /app/main

ENTRYPOINT  ["./main"]
  • To deploy multiple instances on a single machine without port conflicts, we dynamically assign available ports during go-zero startup:
func GetAvailablePort() (int, error) {
	address, err := net.ResolveTCPAddr("tcp", "0.0.0.0:0")
	if err != nil {
		return 0, err
	}

	listener, err := net.ListenTCP("tcp", address)
	if err != nil {
		return 0, err
	}

	defer listener.Close()
	return listener.Addr().(*net.TCPAddr).Port, nil
}

Service Registration & Discovery && Configuration Center

  • Key requirements for personal deployment: low cost and reliability.
  • Service registration/discovery uses etcd.
  • Configuration center also leverages etcd (configs pulled at startup), managed via etcdkeeper with built-in JSON/YAML support.

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  • docker-compose for infrastructure setup:
version: '3'

services:
  etcd:
    container_name: etcd
    image: bitnami/etcd:3
    restart: always
    environment:
      - ETCDCTL_API=3
      - ALLOW_NONE_AUTHENTICATION=yes
      - ETCD_ADVERTISE_CLIENT_URLS=http://127.0.0.1:2379
    volumes:
      - "./data/etcd:/bitnami/etcd/data"
    network_mode: host
  etcdkeeper:
    hostname: etcdkeeper
    image: evildecay/etcdkeeper:v0.7.6
    network_mode: host
    restart: always

CI

  • Using Coding for CI/CD with 10 free build hours/month.
  • Environment variables SERVICE_PATH (build target) and SERVICE_NUMBER (instance count) are injected during builds.
  • Deployment pseudo-code:
script {
  def count = SERVICE_NUMBER.toInteger();
  echo "Deploying: ${count} instances"
  for (int i = 0; i < count; i++) {
    sshCommand(
      remote: remoteConfig,
      command: "docker run --cpus=0.5 --memory=100m -d --net=host --restart=always --name ${SERVICE_NAME}-${i} ${IMAGE_NAME}:${CI_BUILD_NUMBER}",
      sudo: true,
    )
    echo "${SERVICE_NAME}-${i}..."
  }
}

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End

  • Final deployment shows multiple service instances running:

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4.png