How to create a Mongo Docker Image with default collections and data?

Question

I need support here to build my own mongo docker image.

I have a list of scripts to create and insert data into the MongoDB that shall be called in my Dockerfile to

Answer 1

During a docker image build, each build command like RUN is launched in it's own docker container and then when the command completes the data is committed as an image. If you run dockviz images --tree while doing a build you will get the idea.

In your case mongod has started and stopped long before you need it. You need to start mongo and run your scripts all in the one RUN step. You can achieve that by using a shell script that launches mongod and inserts your data.

Your Dockerfile will run:

RUN mongo_create_insert.sh

Then mongo_create_insert.sh contains all your mongo dependent steps:

#!/usr/bin/env bash

mongod --fork --logpath /var/log/mongodb.log --dbpath /data/db/

FILES=scripts/*-create.js
for f in $FILES; do mongo mydb $f; done

FILES=scripts/*-insert.js
for f in $FILES; do mongo mydb $f; done

mongod --shutdown

As a side note, I tend to install Ansible in my base image and use that to provision Docker images in single RUN command rather than doing lots of shell RUN steps in a Dockerfile (which is just a glorified shell script in the end). You lose some of the build caching niceness but we've moved on from provisioning with shell scripts for a reason.