Docker_Compose_With_Mulitple_Local_Containers

 To do below

i.e Get the number of Impressions.

and scale them as per need.

Same steps what we followed

https://automationknowledgesharing2020.blogspot.com/2020/08/dockerlearning.html

i.e

1.package.json

2.index.js

3.Dockerfile

Create new file

C:\Users\manjunathk\impressions>

add/create the below

Steps

docker build .

docker build -t manjunathk/impressions:latest .

docker run manjunathk/impressions

docker run redis

2 containers are isolated

Note: Get rid off Docker cli we shall use Docker Compose

services are  type of container 

2 services i.e redis and node-app inside docker-compose.yml file  take the form of 2 different docker container

so create docker-compose.yml as below

index.js

const express = require("express");

const redis = require("redis");

const process = require("process");

const app = express();

const client = redis.createClient({

  host: "redis-server",

  port: 6379

});

client.set("visits", 0);

app.get("/", (req, res) => {

  //process.exit(0)

  client.get("visits", (err, visits) => {

    res.send("Number of visits " + visits);

    client.set("visits", parseInt(visits) + 1);

  });

});

app.listen(8081, () => {

  console.log("listening on port 8081");

});

Note:

If running container crashes, we can follow belowsteps,

package.json

{

  "dependencies": {

    "express": "*",

    "redis": "2.8.0"

  },

  "scripts": {

    "start": "node index.js"

  }

}

Dockerfile

FROM node:alpine

WORKDIR '/app'

COPY package.json .

RUN npm install

COPY . .

CMD ["npm","start"]

docker-compose.yml

version: "3"

services:

  redis-server:

    image: "redis"

  node-app:

    restart: on-failure

    build: .

    ports:

      - "4001:8081"

docker ps

docker stop 6d40abcbf151 35f8c7f9bc18

after stopping containers

docker-compose up

docker-compose ps