DOCKER : MongooseError [MongooseServerSelectionError]: getaddrinfo ENOTFOUND mongo

Question

I am trying to connect mongodb with my app in docker container. I'm using mongoose package, this is the code that i wrote

mongoose.connect("mongodb://mongo:27016/IssueTracker", { useNewUrlParser: true,useUnifiedTopology: true },(err: Error) => {
    err ? console.log(err) : console.log("Mongodb database connected");
}); 

This i my docker-compose.yml file

version: "3"
services:
    app:
        container_name: IssueTracker
        restart: always
        build: .
        ports: 
            - '9000:9000'
        links:
            - mongo
    mongo:
        container_name: mongo
        image: mongo
        ports:
            - '27017:27016'

And here is my Dockerfile

FROM node:13

WORKDIR /app

COPY package*.json ./

RUN npm install

COPY . .

EXPOSE 9000

RUN ["npm","run","dev"]

This the error which i get when i try to run docker-compose up in my docker cmdline

server started on port 9000
MongooseError [MongooseServerSelectionError]: getaddrinfo ENOTFOUND mongo
        at new MongooseServerSelectionError (/app/node_modules/mongoose/lib/error/serverSelection.js:22:11)
        at NativeConnection.Connection.openUri (/app/node_modules/mongoose/lib/connection.js:823:32)
        at Mongoose.connect (/app/node_modules/mongoose/lib/index.js:333:15)
        at Object.<anonymous> (/app/src/app.ts:9:10)
        at Module._compile (internal/modules/cjs/loader.js:1123:30)
        at Module.m._compile (/app/node_modules/ts-node/src/index.ts:839:23)
        at Module._extensions..js (internal/modules/cjs/loader.js:1143:10)
        at Object.require.extensions.<computed> [as .ts] (/app/node_modules/ts-node/src/index.ts:842:12)
        at Module.load (internal/modules/cjs/loader.js:972:32)
        at Function.Module._load (internal/modules/cjs/loader.js:872:14)
        at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12)
        at main (/app/node_modules/ts-node/src/bin.ts:227:14)
        at Object.<anonymous> (/app/node_modules/ts-node/src/bin.ts:513:3)
        at Module._compile (internal/modules/cjs/loader.js:1123:30)
        at Object.Module._extensions..js (internal/modules/cjs/loader.js:1143:10)
        at Module.load (internal/modules/cjs/loader.js:972:32) {
      reason: TopologyDescription {
        type: 'Single',
        setName: null,
        maxSetVersion: null,
        maxElectionId: null,
        servers: Map(1) { 'mongo:27016' => [ServerDescription] },
        stale: false,
        compatible: true,
        compatibilityError: null,
        logicalSessionTimeoutMinutes: null,
        heartbeatFrequencyMS: 10000,
        localThresholdMS: 15,
        commonWireVersion: null
      },
      [Symbol(mongoErrorContextSymbol)]: {}
    }

Tried to check if any of my container in docker are using the mentioned port so that might create this error and none were using the same port. I'm new to docker so don't know so much about it i tried to check some online solutions but it didn't help

Answer 1

Try creating and using a network instead of link

version: "3"
services:
    app:
        container_name: IssueTracker
        restart: always
        build: .
        ports: 
            - '9000:9000'
        networks: #here
            - my-network
    mongo:
        container_name: mongo
        image: mongo
        ports:
            - '27017:27016'
        networks: #here
            - my-network 
    
    networks: #here
        my-network:
            driver: bridge