djTezos: Django-Tezos

Django-Tezos provides Django Models and uWSGI Spooler (djCall) integration with PyTezos.

Install djTezos

Install djtezos with pip then add djtezos to INSTALLED_APPS.

Run ./manage.py migrate to create tables for djtezos models.

You need a SECRET_KEY that is sufficiently long for AES.

Add Blockchains

Blockchain is the first model you have to manage, you can do it in the admin. For any blockchain, you can choose a Python Provider Class, such as djtezos.tezos.Provider or djtezos.fake.Provider for a mock that you can use in tests.

Example:

tzlocal = Blockchain.objects.create(
    name='tzlocal',
    endpoint='http://tz:8732',
    provider_class='djtezos.tezos.Provider',
    is_active=True,
    confirmation_blocks=1,
)

Run tzlocal with: docker run --name tz --rm --publish 8732:8732 yourlabs/tezos

Add to /etc/hosts: tz on line starting with 127.0.0.1

In gitlab-ci, add:

services:
- name: yourlabs/tezos
  alias: tz

Create accounts

Create an account for a user:

account = user.account_set.create(blockchain=tzlocal)
account.generate_private_key()
account.save()

Users can have as many accounts as you want.

Queue

Transactions are queued in the database with the Transaction model. You can emit 3 types of Transactions.

Deploy a smart contract

Create a Transaction with a contract_micheline to deploy a smart contract:

    contract = Transaction.objects.create(
        sender=account,
        name='TICKR',
        contract_micheline=mich,
        contract_name='PyMich FA 1.2',
        args={'int': '1'},
        state='deploy',
    )

You may then retreive it through either of the Transaction model and the Contract proxy model.

Call a smart contract function

Call a smart contract function with a new Transaction:

    call = Transaction.objects.create(
        sender=account,
        contract=contract,
        function='replace',
        args=[3],
        state='deploy',
    )

This calls the replace function with only one arg: an integer of 3.

A Call proxy model is also available to retrieve.

Execute a transfer

Create a transfer on the blockchain:

    transfer = Transaction.objects.create(
        sender=account,
        receiver=account2,
        amount=10000,
        state='deploy',
    )

Migrate from v0.4.x

Callbacks have been rewritten in a release candidate version, where you need to:

• call Account.generate_private_key() and Account.save() to be able to deploy with it, or provision the private key by yourself through the AES encryption defined in models.py
• run at repeated intervals: ./manage.py djtezos_sync, will catch up backlog at first, then sync incrementally, support reorg
• run at repeated intervals: ./manage.py djtezos_balance

Also, you can't use a form to show a sender field without filling it.

Migrate from djblockchain

1. change all your imports
2. remove migration dependencies to djblockchain to djtezos.0001_initial
3. execute the following SQL in production

alter table djblockchain_account rename to djtezos_account;
alter table djblockchain_blockchain rename to djtezos_blockchain;
alter table djblockchain_transaction rename to djtezos_transaction;
alter table djtezos_transaction drop column block_id;
drop table djblockchain_block;
alter table djtezos_transaction add column contract_micheline json null;
alter table djtezos_transaction add column amount int null;
insert into django_migrations (app, name, applied) values ('djtezos', '0001_initial', now());
update djtezos_blockchain set provider_class = replace(provider_class, 'djblockchain', 'djtezos');

Then, you might still have Blockchain objects with Ethereum provider, this has not bee ported from djblockchain, you may deactivate them by setting is_active=False or you can delete them but that will cascade delete of all their transactions which might not be what existing users expect to happen on your platform...