How to use Docker to containerize the Go Web project and realize rapid deployment and operation in different environments?

With the popularity of microservices, Docker has become a very popular containerization technology, especially for developers who need to deploy and maintain multiple applications. This article will introduce how to use Docker to containerize Go Web projects and implement rapid deployment and operation in different environments.

Introduction

Go is an efficient, modern, fast-growing programming language ideal for building web applications. And Docker is a lightweight containerization technology that enables your applications to run anywhere with isolation and portability.

In order for a Go Web project to run in a Docker container, we need to complete the following steps:

1. Write a Dockerfile to generate a Docker image.
2. Build the Docker image.
3. Run Docker images as containers.

Next, we will highlight these steps.

Write Dockerfile

A Dockerfile is a text file containing instructions and parameters for automatically building a Docker image. When writing your Dockerfile, take into account the environment and dependencies your Go web project will need.

Here is an example of a basic Dockerfile (assuming your Go Web project is called myapp):

FROM golang:1.17-alpine AS builder

RUN apk update && apk add --no-cache git ca-certificates tzdata && update-ca-certificates
RUN mkdir /build
WORKDIR /build

COPY . .
RUN go mod download
RUN go build -o myapp

FROM alpine:3.14.2
COPY --from=builder /build/myapp /usr/local/bin/myapp

CMD ["myapp"]

In the example above, we first used golang:1.17-alpineas the base image. Next, install some necessary dependent packages and set the time zone, and then use COPYthe command to copy the code in our current directory to the container's /builddirectory. Run go mod downloadto download the project dependencies and go buildbuild our Go Web project binaries with myapp.

Finally, we used alpine:3.14.2as the runtime image and myappcopied the built binaries to /usr/local/bin/the directory. Finally, use CMDthe directive to specify the command for the container to start.

Build a Docker image

After the Dockerfile is written, you can use docker buildthe command to build the Docker image. Execute the following command:

docker build -t myapp-image .

Among them, -tthe parameter specifies the name of the image, myapp-imagewhich is the name of the image we created. .Indicates the path where the Dockerfile is located. If your Dockerfile is in another path, please use the corresponding path to overwrite it ..

After the build is successful, you can use docker imagesthe command to list all mirrors. You can see the image we just built:

REPOSITORY      TAG             IMAGE ID       CREATED          SIZE
myapp-image     latest          e3e61d272f9d   20 seconds ago   13.6MB

Run Docker images as containers

Now that we have successfully generated a Docker image, we can docker runlaunch it as a container using the command. Execute the following command:

docker run -p 8080:8080 myapp-image

The -pparameter is to map port 8080 inside the container to port 8080 of the host. You can use your own port, just modify -pthe parameter. After the container starts, you can visit in your browser http://localhost:8080to see if your application is running.

Deploy the image to the cloud

When your application is ready to run in production, you can use a cloud service provider's container platform (such as AWS ECS, Google Cloud Container Engine, Azure Container Service, etc.) to deploy your Docker image.

1. Push the Docker image to Docker Hub or other mirror warehouses.

   # 首先需要在 Docker Hub 上注册一个账号，并创建一个名为 myapp 的 repository
   docker login
   docker tag myapp-image <your-docker-username>/myapp:latest
   docker push <your-docker-username>/myapp:latest
   

2. Create a service or a task on your cloud provider's container platform and push your Docker image to deploy on it.

   # AWS ECS 示例
   # 首先需要在 AWS ECS 中创建一个 cluster 和 task definition，然后在该 task definition 中设置镜像名称为：your-docker-username/myapp:latest。
   # 接着创建一个 service，将该 task definition 分配给该 service，即可完成部署。
   

Summarize

In this article, we covered how to use Docker images to deploy Go web projects. Firstly, the Dockerfile is written, and the required environment and dependencies are stipulated in it, then the docker buildDocker image is built using the command, and finally docker runit is started as a container using the command. Additionally, it discusses how to deploy Docker images to the cloud for use in production.