Build a hot reload development environment with Docker-compose using Realize of Go

Introduction

This article is the 14th day article of ITRC Advent Calendar 2020. Previous article → Help Dockerman (Network) Hello RIN1208 This time, we want to build a hot reload of the development environment in the Docker-compose using the Realize.

Required environment

• docker-compose
• mac os

I will explain in the above environment

To construct

The repository is here

The following 5 files are required to build the hot reload development environment this time.

• Dockerfile
• docker-compose.yml --go.mod package management --.realize.yml realize configuration file --go project

First install

$ go get -u github.com/oxequa/realize

Write a Dockerfile

First, create a Dockerfile. We do not copy files here. The reason will be explained later.

FROM golang:1.14

RUN go get github.com/oxequa/realize 

ENV CGO_ENABLED=0 \
    GOOS=linux \
    GOARCH=amd64 \
    GO111MODULE=on

EXPOSE 8080

CMD ["realize", "start", "--build","--run"]

Write docker-compose.yml

Next, write docker-compose.yml. Set volumes here. Please note that if you copy with Dockerfile, it will be copied when the container is built, so you cannot develop by hot reload. I was addicted to it without noticing it

version: '3'
services:

  api:
    build: .
    ports:
      - "8080:8080"
    tty: true
    volumes:
      - ./:/app
    working_dir: /app

Write .realize.yml

Then create .realize.yml. Detailed explanation will be explained in the comments

settings:
  legacy:
    force: true
    interval: 0s
schema:
- name: test
  path: .
  commands:
    install: #Executed when the file is modified. This time I build it and specify it in a file called main
      status: true
      method: go build -o main main.go 
    run: #Running the built file
      status: true
      method: ./main 
  watcher: #Here we have selected the files to monitor
    extensions:
    - go
    - env
    paths: #Here, the directory to be monitored is selected./If you want to monitor only the files under the api/It's okay if you change it to api
    - /
    ignored_paths: #Here we have selected the files to exclude from monitoring
    - .git
    - .realize
    - vendor

Create a go project

Create a go project as you like. This time I will create an api server using gin

package main

import (
	"github.com/gin-gonic/gin"
)

func main() {
	r := gin.Default()
	r.GET("/", hoge)
	r.Run() 
}

func hoge(c *gin.Context) {
	c.JSON(200, "hogeaaaaaae")
}

Try to start

Let's start it.

$ docker-compose build
$ docker-compose up -d 

Execute the above command to start the container. If you check http: // localhost: 8080/with your browser or curl, it will return as hogeaaaaaae. Also, if you change it to huga, it will come back as huga, and you can build a hot reload development environment.

At the end

Thank you for reading this far. I mentioned Realize itself more than half a year ago, but I didn't write it in the article, so I wrote it in this article. I hope it helps those who are trying to build a hot reload development environment with Docker-compose using Realize. Also, if you have any mistakes, please let us know in the comments.