SqlAlchemy + Alembic + DYNACONF +SSL enabled

env.py

from __future__ import with_statement
import sys,os

from logging.config import fileConfig

from sqlalchemy import engine_from_config
from sqlalchemy import pool

from alembic import context
sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
from models import Base

# Please define Database name to be used
DATABASE = "DATABASE"

# this is the Alembic Config object, which provides
# access to the values within the .ini file in use.
config = context.config

# Interpret the config file for Python logging.
# This line sets up loggers basically.
fileConfig(config.config_file_name)

# add your model's MetaData object here
# for 'autogenerate' support
# from myapp import mymodel
# target_metadata = mymodel.Base.metadata
target_metadata = Base.metadata

# other values from the config, defined by the needs of env.py,
# can be acquired:
# my_important_option = config.get_main_option("my_important_option")
# ... etc.


def get_db_url():
    """Get url DB connection based on environment variables
    more details on README.MD file

    Args:
        None

    Returns:
        url db connect (string)
    """
    import yaml
    env = os.getenv("ENV_FOR_DYNACONF", "production")
    secrets_file = os.getenv("SECRETS_FOR_DYNACONF")

    if not secrets_file:
        raise "Error: Not found 'secrets.yaml' file. Please, configure the env: SECRETS_FOR_DYNACONF"

    with open(secrets_file, 'r') as stream:
        data_loaded = yaml.safe_load(stream)
        db_credentials = data_loaded[env]["databases"][DATABASE]

    if db_credentials is None:
        raise "Error: No database configuration found in secrets.yaml"

    sqlalchemy_url = "{}://{}:{}@{}/{}".format(
        db_credentials["driver"],
        db_credentials["user"],
        db_credentials["pass"],
        db_credentials["host"],
        db_credentials["name"]
    )

    return sqlalchemy_url


def run_migrations_offline():
    """Run migrations in 'offline' mode.

    This configures the context with just a URL
    and not an Engine, though an Engine is acceptable
    here as well.  By skipping the Engine creation
    we don't even need a DBAPI to be available.

    Calls to context.execute() here emit the given string to the
    script output.

    """
    url = config.get_main_option("sqlalchemy.url")
    context.configure(
        url=url, target_metadata=target_metadata, literal_binds=True, compare_type=True
    )

    with context.begin_transaction():
        context.run_migrations()


def run_migrations_online():
    """Run migrations in 'online' mode.

    In this scenario we need to create an Engine
    and associate a connection with the context.

    """

    # change sqlalchemy.url
    db_config = config.get_section(config.config_ini_section)
    db_config["sqlalchemy.url"] = get_db_url()

    connectable = engine_from_config(
        db_config,
        prefix="sqlalchemy.",
        poolclass=pool.NullPool,
        connect_args={'ssl':'true'}
    )

    with connectable.connect() as connection:
        context.configure(
            connection=connection, target_metadata=target_metadata, compare_type=True
        )

        with context.begin_transaction():
            context.run_migrations()


if context.is_offline_mode():
    run_migrations_offline()
else:
    run_migrations_online()