Connection error: docker compose: Loopback4 + Mongo - express

Question

I run the project with:
clean volumes & containers, then docker compose up --build
Tried creating different users for mongo. Made different settings for the docker file. For docker compose.
I assume that the error is somewhere between loopback & mongodb container.
For watch changes i use tsc-watch. Dont know it cause any bugs here, not sure.
Configuration
package.json
{
"name": "lympha-backend",
"version": "0.0.1",
"description": "lympha backend",
"keywords": [
"loopback-application",
"loopback"
],
"main": "dist/index.js",
"types": "dist/index.d.ts",
"engines": {
"node": "14 || 16 || 18 || 19"
},
"scripts": {
"dev": "tsc-watch --target es2017 --outDir ./dist --onSuccess \"node .\"",
"build": "lb-tsc",
"build:watch": "lb-tsc --watch",
"watch": "lb-tsc --watch",
"lint": "yarn run eslint && yarn run prettier:check",
"lint:fix": "yarn run eslint:fix && yarn run prettier:fix",
"prettier:cli": "lb-prettier \"**/*.ts\" \"**/*.js\"",
"prettier:check": "yarn run prettier:cli -l",
"prettier:fix": "yarn run prettier:cli --write",
"eslint": "lb-eslint --report-unused-disable-directives .",
"eslint:fix": "yarn run eslint --fix",
"pretest": "yarn run rebuild",
"test": "lb-mocha --allow-console-logs \"dist/__tests__\"",
"posttest": "yarn run lint",
"test:dev": "lb-mocha --allow-console-logs dist/__tests__/**/*.js && yarn run posttest",
"docker:build": "docker build -t lympha-backend .",
"docker:run": "docker run -p 3000:3000 -d lympha-backend",
"premigrate": "yarn run build",
"migrate": "node ./dist/migrate",
"preopenapi-spec": "yarn run build",
"openapi-spec": "node ./dist/openapi-spec",
"prestart": "yarn run rebuild",
"start": "node -r source-map-support/register .",
"clean": "lb-clean dist *.tsbuildinfo .eslintcache",
"rebuild": "yarn run clean && yarn run build"
},
"repository": {
"type": "git",
"url": ""
},
"license": "",
"files": [
"README.md",
"dist",
"src",
"!*/__tests__"
],
"dependencies": {
"#loopback/boot": "^5.0.7",
"#loopback/core": "^4.0.7",
"#loopback/repository": "^5.1.2",
"#loopback/rest": "^12.0.7",
"#loopback/rest-crud": "^0.15.6",
"#loopback/rest-explorer": "^5.0.7",
"#loopback/service-proxy": "^5.0.7",
"loopback-connector-mongodb": "^5.2.3",
"tsc-watch": "^6.0.0",
"tslib": "^2.0.0"
},
"devDependencies": {
"#loopback/build": "^9.0.7",
"#loopback/eslint-config": "^13.0.7",
"#loopback/testlab": "^5.0.7",
"#types/node": "^14.18.36",
"eslint": "^8.30.0",
"source-map-support": "^0.5.21",
"typescript": "~4.9.4"
}
}
Docker compose
version: '3.9'
services:
mongodb:
image: mongo
container_name: mongodb
ports:
- "27017:27017"
environment:
- MONGO_INITDB_ROOT_USERNAME=root
- MONGO_INITDB_ROOT_PASSWORD=password
- MONGO_INITDB_DATABASE=admin
restart: always
volumes:
- ./mongo-init.js:/docker-entrypoint-initdb.d/mongo-init.js:ro
- mongodb:/data/db
backend:
container_name: backend
build:
context: .
dockerfile: ./lympha-backend/Dockerfile
command: ["yarn", "dev"]
ports:
- 4000:3000
environment:
NAME: TEST_DEVELOPMENT
PORT: 3000
DB_NAME: lympha_db
DB_USER: root
DB_PASS: password
restart: always
volumes:
- ./lympha-backend:/home/node/app
depends_on:
- mongodb
links:
- mongodb
volumes:
backend:
mongodb:
Dockerfile
# Check out https://hub.docker.com/_/node to select a new base image
FROM node:16-slim
# Set to a non-root built-in user `node`
USER node
# Create app directory (with user `node`)
RUN mkdir -p /home/node/app
RUN mkdir -p /home/node/app/dist
WORKDIR /home/node/app
RUN pwd
COPY --chown=node package*.json ./
# RUN npm install
RUN yarn
# Bundle app source code
COPY --chown=node . .
# Bind to all network interfaces so that it can be mapped to the host OS
ENV HOST=0.0.0.0 PORT=3000
EXPOSE ${PORT}
mongo-init.js
db.createUser({
user: 'admin',
pwd: 'password',
roles: [
{ role: 'root', db: 'admin' },
]
});
db = db.getSiblingDB('lympha_db');
db.createCollection("lympha_db"); //MongoDB creates the database when you first store data in that database
db.createUser(
{
user: "lympha",
pwd: "lympha",
roles: [
{
role: "readWrite",
db: "lympha_db"
}
]
}
);
Mongo terminal
Look at the picture
Logs
Mongodb logs
Look at the picture
Backend logs
{
name: 'mongodb',
connector: 'mongodb',
host: 'localhost',
port: 27017,
user: 'admin',
password: 'password',
database: 'admin'
}
Server is running at http://127.0.0.1:3000
Try http://127.0.0.1:3000/ping
Connection fails: MongoServerSelectionError: connect ECONNREFUSED 127.0.0.1:27017
It will be retried for the next request.
/home/node/app/node_modules/mongodb/lib/utils.js:698
throw error;
^
MongoServerSelectionError: connect ECONNREFUSED 127.0.0.1:27017
at Timeout.\_onTimeout (/home/node/app/node_modules/mongodb/lib/core/sdam/topology.js:438:30)
at listOnTimeout (node:internal/timers:559:17)
at processTimers (node:internal/timers:502:7)
Emitted 'error' event on MongoDataSource instance at:
at MongoDataSource.postInit (/home/node/app/node_modules/loopback-datasource-juggler/lib/datasource.js:502:16)
at onError (/home/node/app/node_modules/loopback-connector-mongodb/lib/mongodb.js:325:21)
at /home/node/app/node_modules/loopback-connector-mongodb/lib/mongodb.js:333:9
at /home/node/app/node_modules/mongodb/lib/utils.js:695:9
at /home/node/app/node_modules/mongodb/lib/mongo_client.js:285:23
at connectCallback (/home/node/app/node_modules/mongodb/lib/operations/connect.js:367:5)
at /home/node/app/node_modules/mongodb/lib/operations/connect.js:554:14
at connectHandler (/home/node/app/node_modules/mongodb/lib/core/sdam/topology.js:286:11)
at Object.callback (/home/node/app/node_modules/mongodb/lib/core/sdam/topology.js:672:9)
at Timeout.\_onTimeout (/home/node/app/node_modules/mongodb/lib/core/sdam/topology.js:443:25)
at listOnTimeout (node:internal/timers:559:17)
at processTimers (node:internal/timers:502:7) {
reason: TopologyDescription {
type: 'Single',
setName: null,
maxSetVersion: null,
maxElectionId: null,
servers: Map(1) {
'localhost:27017' =\> ServerDescription {
address: 'localhost:27017',
error: Error: connect ECONNREFUSED 127.0.0.1:27017
at TCPConnectWrap.afterConnect \[as oncomplete\] (node:net:1278:16) {
name: 'MongoNetworkError'
},
roundTripTime: -1,
lastUpdateTime: 7989795,
lastWriteDate: null,
opTime: null,
type: 'Unknown',
topologyVersion: undefined,
minWireVersion: 0,
maxWireVersion: 0,
hosts: \[\],
passives: \[\],
arbiters: \[\],
tags: \[\]
}
},
stale: false,
compatible: true,
compatibilityError: null,
logicalSessionTimeoutMinutes: null,
heartbeatFrequencyMS: 10000,
localThresholdMS: 15,
commonWireVersion: null
}
}
I cant connect lb4 and mongo.
I can start for scratch to figure out what is going on. Ask everything you want, i will do everything is needed as well. Ping me please.

Answer 1

When you start in compose, it sets up single network. (https://docs.docker.com/compose/networking/)
In short, each container can see another by service name. In your case - mongodb, not localhost
try to change:
- host: 'localhost',
+ host: 'mongodb',