tezos-delegation

tezos delegation is a Golang project composed of a delegation aggregation cron which aggregates the new delegation from the tezos blockchain and an api service to expose the data.

Requirements

• go
• mage
• docker
• docker-compose

Setup

In the dev-tools, cron.delegation_aggregation and delegation_api folders, copy and paste the .env.dist file to .env and fill the missing values.

Development

You can do a mage to get a list of available commands.

Build all

mage build

Lint all

mage lint

Run all tests

mage test:unit

Start a mongodb docker container

mage mongodb:start 

Run delegation aggregation cron

cd cron.delegation_aggregation
mage run

Run delegation api server

cd service.delegation_api
mage run

Calling the api endpoint

curl --location 'http://localhost:8088/xtz/delegations?page=1&size=100' | jq

jq is a lightweight command-line JSON processor https://jqlang.github.io/jq/

Or load the dev-tools/Tezos.postman_collection.json file in postman.

Architecture choices

Project structure and build tool

It is probably not the simplest structure, but I choose to use a monorepo structure and mage as a build tool because it is what I know from my current experience and comfortable with (I have been working with Golang for around 2 years). Moreover, it is a structure that can be easily scaled and deployed on kubernetes for example with a specific deployment for each service.

Delegation aggregation cron

The delegation aggregation cron is a Golang program which aggregates the new delegation from the tezos blockchain, storing it in a mongodb database.

I choose to use a mongodb database because it is a NoSQL database, which is a good fit for delegation data which are just a collection of key-value pairs. Moreover, it can handle a large amount of data and can be scaled horizontally.

I choose to separate it from the api service, so it could be configured as a cron job and a specific schedule on kubernetes for example. We would have to adjust the cron schedule related to the number of delegations we expect to have, and the limit parameter of the tezos api (currently set to 100).

Delegation api service

The delegation api service is a Golang program which exposes the delegation data stored by the cron. It is a REST api which exposes the data in a paginated way to limit the amount of data returned. I choose to separate it from the delegation cron, so it could be scaled easily and independently, for example on kubernetes with autoscaler.

Improvements

• Add more unit tests
• Add integration tests
• Add a swagger documentation
• Add a CI/CD pipeline
• Add a kubernetes deployment
• Tezos has a websocket api, it could be interesting to use it to get the new delegations in real time