BusinessAuditLog

This is a simple microservice developed to complement my talk about Phoenix Framework. The main purpose of this microservice is storing audit log messages about business relevant events happening in an imaginary distributed system.

Audit Log Entry consists of the following fields:

• actor_id - id of an actor that has performed an action
• actor_type - type of the actor: e.g "user", "system"
• action - the action performed
• resource_id - id of resource on which the action was performed
• resource_type - type of resource
• created_at - timestamp

Audit Log Entry creation happens as an async reaction to a message published to AWS SQS queue.

Features

• it listens to messages from AWS SQS queue
• it stores an audit log entry into database
• it provides API to fetch audit log entries
• it has a web UI to display audit log entries
• it has a web UI to tail audit log (new entries are broadcaset from server via websockets)

Installation

• Install Elixir: brew install elixir
• Install Node.js: brew install node
• Install Docker https://docs.docker.com/docker-for-mac/install/
• Install aws cli: brew install awscli
• Add your AWS credentials to ~/.aws/credentials
• Start a Docker container with database: docker-compose up -d
• Install dependencies with mix deps.get
• Create, migrate and populate your database with mix ecto.setup
• Install Node.js dependencies with cd assets && npm install

Running locally

Start Phoenix endpoint with QUEUE_NAME=<your AWS account>/<queue name> mix phx.server mix phx.server

Now you can visit localhost:4000 from your browser and see list of audit log entries.

Publishing new audit log entry

Execute this command in your terminal:

aws sqs send-message --queue-url https://eu-west-1.amazonaws.com/<your AWS account>/<queue name> --message-body '{ "event_type": "CREATE_BUSINESS_AUDIT_LOG_ENTRY", "created_at": "2017-03-14T11:17:00Z", "payload": { "actor_id": "2", "actor_type": "user", "action": "Got excited about Elixir", "resource_type": "user", "resource_id": "2" } }'

API

There is only one API endpoint:

/api/entries/:resource_type/:resource_id

It returns a paginated list of audit log entries for given resource in JSON format.

Here is usage example:

http://localhost:4000/api/entries/user/2?page_size=5&page=1

Web UI

• Open http://localhost:4000 to see a paginated list of audit log entries.

• Open http://localhost:4000/tail to tail the log. Try to publish some messages to the queue and see how they are delivered to your browser via Websocket connection.