通过 docker-compose 启动 mongoDB

Question

Let's say I have the following docker compose that consists of 2 services: a nodeJS app and a mongoDB database that is backing it:

version: "3.8"

services:
  mongodb-local:
    image: mongo:latest
    restart: unless-stopped
    env_file: ./.env
    # see: https://stackoverflow.com/questions/52373098/disable-default-authentication-in-mongo-docker
#    environment:
#      - MONGO_INITDB_ROOT_USERNAME=$MONGODB_USER
#      - MONGO_INITDB_ROOT_PASSWORD=$MONGODB_PASSWORD
#      - MONGO_INITDB_DATABASE=$MONGODB_DATABASE
    ports:
      - "27017:27017"
    volumes:
      - db:/data/db
  app:
    depends_on:
      - mongodb-local
    build: .
    restart: unless-stopped
    env_file: ./.env
    ports:
      - 3000:3000
    environment:
      - DB_HOST=mongodb
      - DB_USER=$MONGODB_USER
      - DB_PASSWORD=$MONGODB_PASSWORD
      - DB_NAME=$MONGODB_DATABASE
      - DB_PORT=$MONGODB_DOCKER_PORT
    stdin_open: true
    tty: true

Let's say that the nodeJS code uses mongoose to kind of bootsrap all the schemas and models, in such a way that once the nodeJS app starts, I can hit specific endpoints to register users, add some data, etc.

What I want to do now is to be able to "seed" the DB in such a way that I create users and/or add data "upon start up" so that when doing: docker-compose up I will get a "seeded" DB with the app ready to use for local develpment.

Now it's a 2 step process:

1. run docker-compose up to spin up both services
2. Run curl commands via postman against the nodeJS app to seed the DB by making mongoose "work".

What I want is a mechanism to "seed" the DB with a few test data upon doing a docker-compose up immediately.

I tried using the curl image like so:

version: "3.8"

services:
  mongodb-local:
    image: mongo:latest
    restart: unless-stopped
    env_file: ./.env
    # see: https://stackoverflow.com/questions/52373098/disable-default-authentication-in-mongo-docker
#    environment:
#      - MONGO_INITDB_ROOT_USERNAME=$MONGODB_USER
#      - MONGO_INITDB_ROOT_PASSWORD=$MONGODB_PASSWORD
#      - MONGO_INITDB_DATABASE=$MONGODB_DATABASE
    ports:
      - "27017:27017"
    volumes:
      - db:/data/db
  app:
    depends_on:
      - mongodb-local
    build: .
    restart: unless-stopped
    env_file: ./.env
    ports:
      - 3000:3000
    environment:
      - DB_HOST=mongodb
      - DB_USER=$MONGODB_USER
      - DB_PASSWORD=$MONGODB_PASSWORD
      - DB_NAME=$MONGODB_DATABASE
      - DB_PORT=$MONGODB_DOCKER_PORT
    stdin_open: true
    tty: true

  curl-run:
    depends_on:
      - mongodb-local
      - app
    image: curlimages/curl
    command: "sleep 20 && curl --location --request POST 'http://localhost:3000/register' \
      --header 'Content-Type: application/json' \
      --data-raw '{\
      'username': 'user',\
      'password': 'pass',\
      'role': 'admin'\
    }'"

volumes:
  db:

but, no luck... Any pointers would be greatly appreciated.

I have read about mongodump and restore but didn't manage to get that working.

Note that if there is an approach to do it directly via a volume or directly against the DB container that would be the best!

Thanks in advance!

Answer 1

Have you tried using /docker-entrypoint-initdb.d ?

From the documentation :

When a container is started for the first time it will execute files with extensions.sh and.js that are found in /docker-entrypoint-initdb.d. Files will be executed in alphabetical order. .js files will be executed by mongosh (mongo on versions below 6) using the database specified by the MONGO_INITDB_DATABASE variable, if it is present, or test otherwise. You may also switch databases within the.js script.

The only caveat I see here is that this likely only works on a fresh build ( docker-compose up -b ) vs. every time it is started. If you don't care about preserving the data between ups/downs, this should work.

Answer 2

I managed to fix this by leveraging a tweak on the mongo image entrypoint: /docker-entrypoint-initdb.d

Essentially, I copy an init file, in Javascript, that gets copied over into the container entrypoint via the volume configuration and that gets executed on startup, which allows me to achieve what I want: seed the DB with data upon startup!

Here's my modified docker service for mongoDB:

services:
  mongodb-local:
    image: mongo:latest
    restart: unless-stopped
    env_file: ./.env
    ports:
      - "27017:27017"
    volumes:
      - ./mongo-init.js:/docker-entrypoint-initdb.d/mongo-init.js:ro
      - db:/data/db

And, here's my actual "seed" file:

print('Start #################################################################');

db = db.getSiblingDB('<some db name>');

console.log(db)

db.createCollection('<a collection>');

db.dams.insertMany([ ....]);

....

print("End #########")