Testing databases in a Docker Container

Setting up Docker locally

Situation: We need have an separate frontend-backend work environment instead of spinning up a test database in our actual database.

We need to separate test environment from dev/prod environment.

For demonstration, I’m pulling a docker container into my local machine to test a database for the bounty board project.

Enter Docker. Assuming a dev has already setup the docker container in a specific feature branch feature/docker-compose-mongo.

# clone repo that contains docker container (bountyboard-docker directory is installed locally)
git clone https://github.com/jordaniza/bounty-board.git bountyboard-docker

# change directory into that directory's root
cd bountyboard-docker

# create new feature branch to match branch you want to pull locally (containing the docker container) 
git checkout -b feature/docker-compose-mongo

# pull container to your local environment
git pull origin feature/docker-compose-mongo

# change directory to folder with "Dockerfile"
cd mongo

# run command to start Docker up
docker-compose up --build

# start up (frontend) App
# install first
yarn && yarn dev

## OPEN LOCALHOST:3000 http://localhost:3000

ENVIRONMENT VARIABLES

We have to change directory into packages/react-app/.env.local to create the .env.local file (changed for security)

# terminal
$ code .env.local

# paste this into the newly opened file

BUILD_ENV=development
MONGODB_DB=bountyboard
#PROD_MONGODB_URI=
MONGODB_URI=mongodb://localhost:27017/bountyboard
NEXT_PUBLIC_DISCORD_SERVER_ID=8******************0
NEXT_PUBLIC_DISCORD_CHANNEL_BOUNTY_BOARD_ID=8******************0

# Public Environments
NEXT_PUBLIC_DAO_CURRENT_SEASON=1
NEXT_PUBLIC_DAO_CURRENT_SEASON_END_DATE=2021-08-31T04:00:00.000Z

# URLs
NEXT_PUBLIC_DAO_BOUNTY_BOARD_URL=https://bountyboard.bankless.community
DISCORD_BOUNTY_BOARD_WEBHOOK=

What happens when you pull a Docker container locally

We are:

• Pulling a folder for MongoDB with the latest scripts, schema, and Dockerfiles
• Using the docker-compose utility, docker-compose up --build to fire up a Mongo container, and a temporary seeding container
• The seeding container runs a set of bash scripts to populate the DB you can see this in mongo/seed.sh

Opening Additional Terminal windows: Mongo

Once, I ran yarn dev I got the Application to fire up, ready - started server on 0.0.0.0:3000, url: http://localhost:3000

but Mongo wasn’t turned on.

First, open up a new terminal, then:

docker exec -it mongo_mongo_1 bash

NOTE: Install DOCKER in VSCode to follow along

Find the Container that’s a GREEN TRIANGLE, right click, then attach shell.

NOTE: This did not work, so I needed to open a 3rd Terminal to type in:

docker exec -it mongo_mongo_1 bash

exec executes a command -it starts an interactive terminal session mongo_mongo_1 is the name of the container and bash is the shell.

NOTE: You should see something like root@4d5cedd1a8a7:/#, then type in the following to fire up Mongo Shell:

mongosh

Another confirmation is Connecting to: mongodb://127.0.0.1:27017/?directConnection=true&serverSelectionTimeoutMS=2000

At this point you can do basic Mongo commands:

show collections

NOTE: I was on the test> database and needed to switch to bountyboard> database where the “test” data was located and ready for testing.

Other commands to run are findOne() or find() just to see the seeded data:

db.bounties.findOne()

NOTE: I did not get the front end to work so for this session, we only tested the database by querying in Mongo shell.

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