The problem is that you are using two FROM instructions, which is referred to as a multi-stage build. The final image will be based on the node image that doesn't contain the mongo database.

* Edit *

here are more details about what is happening:

FROM mongo:latest

• the base image is mongo:latest

FROM node

• now the base image is node:latest. The previous image is just standing there...

RUN mongod

COPY . .

RUN node ./scripts/import-data.js

• now you run mongod and the other commands in your final image that is based on node (which doesn't contain mongo)

It happens because multiple FROM instructions should be used for Multistage Build (check the documentation) and NOT for image creation contains all of present applications.

Multistage builds provide you possibility of delegation building process into container's environment without local application installation.

FROM rabbitmq

...some instructions require rabbitmq...

FROM mongo:latest

...some instructions require mongo...

In other words if you want to create an image with rabbitmq, mongo and other application you have to choose the image and install applications manually.

Use docker-compose (https://docs.docker.com/compose/install/) to run the images rather than attempting to build a new image from a collection of existing images. Your docker-compose.yml might look something like:

version: '3.7'
services:
  portainer:
    image: 'portainer/portainer'
    container_name: 'portainer'
    hostname: 'portainer'
    domainname: 'example.com'
    volumes:
    - '/var/run/docker.sock:/var/run/docker.sock'
    - 'portainer_data:/data'
    ports:
    - '9000:9000'
  rabbitmq:
    image: 'rabbitmq'
    container_name: 'rabbitmq'
    hostname: 'rabbitmq'
    domainname: 'example.com'
    volumes:
    - 'rabbitmq_data:/var/lib/rabbitmq'
  elasticsearch:
    image: 'elasticsearch:7.1.1'
    container_name: 'elasticsearch'
    hostname: 'elasticsearch'
    domainname: 'example.com'
    environment:
    - 'discovery.type=single-node'
    volumes:
    - 'elasticsearch_data:/usr/share/elasticsearch/data'
    ports:
    - '9200:9200'
    - '9300:9300'
  node:
    image: 'node:12'
    container_name: 'node'
    hostname: 'node'
    domainname: 'example.com'
    user: 'node'
    working_dir: '/home/node/app'
    environment:
    - 'NODE_ENV=production'
    volumes:
    - './my-app:/home/node/app'
    ports:
    - '3000:3000'
    command: 'npm start'
  mongo:
    image: 'mongo'
    container_name: 'mongo'
    hostname: 'mongo'
    domainname: 'example.com'
    restart: 'always'
    environment:
    - 'MONGO_INITDB_ROOT_USERNAME=root'
    - 'MONGO_INITDB_ROOT_PASSWORD=example'
    volumes:
    - 'mongo_data:/data/db'
volumes:
  portainer_data:
  rabbitmq_data:
  elasticsearch_data:
  mongo_data: