sample1

sample1 is a vagrant box provisioned by ansible with:

• HAproxy acting as load-balancer
• web application written in Django(Python) running in Docker container to store/list events in DB
• PostgreSQL running in Docker container

Despite there are two instances of web application, PostgreSQL is obviously SPOF in this example.

Dependencies

• ansible=7.3.0
• vagrant=2.4.1

How-to run/setup

# Install ansible dependencies
ansible-galaxy install -p provisioning/roles/ -r requirements.yml
# Start and provision vagrant environment
vagrant up

Web application

Once vagrant environment is up, web application should be reachable at http://localhost:8080.

URIs

Followin URIs are available:

• /events
  • GET to list events in DB
  • POST to push event into DB
• /event/<id>/ to show one particular event stored in DB

Structure of Event

Event is expected to be in JSON format with the following mandatory attributes:

• timestamp - seconds since 1970-01-01 00:00:00 UTC aka Unix timestamp
• message - text

How-to test

# In order to push some event run the following command
curl -XPOST -H 'Content-Type: application/json' http://localhost:8080/events \
    -d '{"timestamp": 1515948504, "message": "Printer is on fire"}'
# To list events stored in DB
curl http://localhost:8080/events
# And to get the detail of particular event
curl http://localhost:8080/event/1/

Extra notes

PostgreSQL configuration is being fetched from ENV variables. Therefore, sadly these variables must be set in order to use manage.py.

• POSTGRES_HOST
• POSTGRES_DB
• POSTGRES_USER
• POSTGRES_PASS

References

• https://github.com/geerlingguy/ansible-vagrant-examples