Docker Stack deployment method steps for web cluster

Docker is becoming more and more mature and its functions are becoming more and more powerful. It is also very convenient to use Docker Stack to build a service cluster. Docker itself provides load function, which is very convenient. I want to share it with you and make a simple tutorial.

environment

I used two centos7 virtual machines to do this tutorial. Their IP addresses are

Main server: 192.168.0.105 // also a private warehouse server Server 2: 192.168.0.49

All the code in this post can be found on GitHub: https://github.com/lpxxn/godockerswarm

Setting up Docker Swarm

I use 192.168.0.105 as the main server and start swarm on it

docker swarm init

After executing the command, the command to join the swarm will be given

Execute the command on 192.168.0.49 to join the swarm

docker swarm join --token SWMTKN-1-425vswwmb8o34uhnmo58w0k4rfzs5okjtye7mokpqps1vl9ymq-0p6pr2gua7l8a6udb67tfndoo 192.168.0.105:2377 

In this way, we have built the swarm, and the two hosts now have a relationship.

Web Services

The web service is a simple interface written in go language, which returns the name of the host: This makes it easy for us to check whether there is load

package main

import (
  "fmt"
  "log"
  "net/http"
  "os"
)

func main() {
  http.HandleFunc("/hi", func(w http.ResponseWriter, r *http.Request) {
    hostName, _ := os.Hostname()
    fmt.Fprintf(w, "HostName: %s", hostName)
  })

  log.Fatal(http.ListenAndServe(":8000", nil))
}

Docker file

Take a look at the Dockerfile:

Execution means copying the code to the corresponding folder, exposing the port, and running the program based on the golang context. Simple, right?

FROM golang

# Copy the current directory contents into the container
COPY ./go/src/github.com/lpxxn/godockerswarm/

WORKDIR /go/src/github.com/lpxxn/godockerswarm/

RUN go build

EXPOSE 8000

CMD ["./godockerswarm"]

Take a look at the folder where the dockerfile file is located

Execute the docker build command in this directory:

docker build . -t goweb:1.0 

You can run the newly generated image

docker run -p 8100:8000 7a7e3 

Submit the image to a private repository

I will say more about how to build a private warehouse server here. You can go to my previous post to check it out.

Address: https://www.jb51.net/article/156168.htm

Because the machines in the cluster automatically retrieve images from the warehouse and then run the program, we need to push the images we generated above to our private warehouse. I built it myself

Rename using tag

docker tag goweb:1.0 lpxxn.com:5000/goweb:1.0 

Push

docker push lpxxn.com:5000/goweb:1.0 

docker-compose file

Next, create the docker-compose.yml file

Image is the image we created above. Run 5 applications, Docker will do its own load, port mapping 8111, automatically restart the service when it fails, and create its own network, which is very useful when there are multiple server services.

For the specific parameters, you can refer to the official tutorial:

https://docs.docker.com/compose/compose-file/

version: "3"
services:
 web:
  image: lpxxn.com:5000/goweb:1.0
  deploy:
   replicas: 5
   resources:
    limits: 
     cpus: "0.1"
     memory: 50M
   restart_policy:
    condition: on-failure
  ports:
   - "8111:8000"
  networks: 
   - gowebnet
networks: 
 gowebnet:

Deploy the application

Now it’s the final stage. Deployment is just as simple. Execute the deploy command.

docker stack deploy -c docker-compose.yml mygoweb 

View started services

docker service ps mygoweb 

Testing Services

Look at these returned host names: they are different. Docker does the load for us.

All the code in this post can be found on GitHub: https://github.com/lpxxn/godockerswarm

The above is the full content of this article. I hope it will be helpful for everyone’s study. I also hope that everyone will support 123WORDPRESS.COM.