Merge pull request #30 from eReuse/feature/alembic-migrations

alembic migrations

README.rst

@@ -86,6 +86,68 @@ Testing
    password ``ereuse``.
 3. Execute at the root folder of the project ``python3 setup.py test``.
 
+
+Migrations
+**********
+At this stage, migration files are created manually.
+Set up the database:
+
+.. code:: bash
+
+   $ sudo su - postgres
+   $ bash $PATH_TO_DEVIHUBTEAL/examples/create-db.sh devicehub dhub
+
+Initialize the database:
+
+.. code:: bash
+
+   $ export dhi=dbtest; dh inv add --common --name dbtest
+
+This command will create the schemas, tables in the specified database.
+Then we need to stamp the initial migration.
+
+.. code:: bash
+
+   $ alembic stamp head
+
+
+This command will set the revision **fbb7e2a0cde0_initial**  as our initial migration.
+For more info in migration stamping please see https://alembic.sqlalchemy.org/en/latest/cookbook.html
+
+
+Whenever a change needed eg to create a new schema, alter an existing table, column or perform any
+operation on tables, create a new revision file:
+
+.. code:: bash
+
+   $ alembic revision -m "A table change"
+
+This command will create a new revision file with name `<revision_id>_a_table_change`.
+Edit the generated file with the necessary operations to perform the migration:
+
+.. code:: bash
+
+   $ alembic edit <revision_id>
+
+Apply migrations using:
+
+.. code:: bash
+
+   $ alembic -x inventory=dbtest upgrade head
+
+Then to go back to previous db version:
+
+.. code:: bash
+
+   $ alembic -x inventory=dbtest downgrade <revision_id>
+
+To see a full list of migrations use
+
+.. code:: bash
+
+   $ alembic history
+
+
 Generating the docs
 *******************
 

alembic.ini

@@ -0,0 +1,74 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = ereuse_devicehub/migrations
+
+# template used to generate migration files
+# file_template = %%(rev)s_%%(slug)s
+
+# timezone to use when rendering the date
+# within the migration file as well as the filename.
+# string value is passed to dateutil.tz.gettz()
+# leave blank for localtime
+# timezone =
+
+# max length of characters to apply to the
+# "slug" field
+#truncate_slug_length = 40
+
+# set to 'true' to run the environment during
+# the 'revision' command, regardless of autogenerate
+# revision_environment = false
+
+# set to 'true' to allow .pyc and .pyo files without
+# a source .py file to be detected as revisions in the
+# versions/ directory
+# sourceless = false
+
+# version location specification; this defaults
+# to alembic/versions.  When using multiple version
+# directories, initial revisions must be specified with --version-path
+# version_locations = %(here)s/bar %(here)s/bat alembic/versions
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+sqlalchemy.url = driver://user:pass@localhost/dbname
+
+
+# Logging configuration
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

ereuse_devicehub/alembic.ini

@@ -0,0 +1,74 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = migrations
+
+# template used to generate migration files
+# file_template = %%(rev)s_%%(slug)s
+
+# timezone to use when rendering the date
+# within the migration file as well as the filename.
+# string value is passed to dateutil.tz.gettz()
+# leave blank for localtime
+# timezone =
+
+# max length of characters to apply to the
+# "slug" field
+#truncate_slug_length = 40
+
+# set to 'true' to run the environment during
+# the 'revision' command, regardless of autogenerate
+# revision_environment = false
+
+# set to 'true' to allow .pyc and .pyo files without
+# a source .py file to be detected as revisions in the
+# versions/ directory
+# sourceless = false
+
+# version location specification; this defaults
+# to alembic/versions.  When using multiple version
+# directories, initial revisions must be specified with --version-path
+# version_locations = %(here)s/bar %(here)s/bat alembic/versions
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+sqlalchemy.url = driver://user:pass@localhost/dbname
+
+
+# Logging configuration
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

ereuse_devicehub/devicehub.py

@@ -10,6 +10,7 @@ from ereuse_utils.session import DevicehubClient
 from flask.globals import _app_ctx_stack, g
 from flask_sqlalchemy import SQLAlchemy
 from teal.teal import Teal
+from teal.db import SchemaSQLAlchemy
 
 from ereuse_devicehub.auth import Auth
 from ereuse_devicehub.client import Client
@@ -115,6 +116,16 @@ class Devicehub(Teal):
             self.db.session.commit()
         print('done.')
 
+
+    def _init_db(self, exclude_schema=None) -> bool:
+        if exclude_schema:
+            assert isinstance(self.db, SchemaSQLAlchemy)
+            self.db.create_all(exclude_schema=exclude_schema)
+        else:
+            self.db.create_all()
+
+        return True
+
     @click.confirmation_option(prompt='Are you sure you want to delete the inventory {}?'
                                .format(os.environ.get('dhi')))
     def delete_inventory(self):

ereuse_devicehub/migrations/README

@@ -0,0 +1 @@
+Generic single-database configuration.

ereuse_devicehub/migrations/env.py

@@ -0,0 +1,88 @@
+from __future__ import with_statement
+
+import os
+from logging.config import fileConfig
+
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from alembic import context
+
+from ereuse_devicehub.config import DevicehubConfig
+
+# 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 = None
+from ereuse_devicehub.db import db
+from ereuse_devicehub.resources.models import Thing
+target_metadata = Thing.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_url():
+    # url = os.environ["DATABASE_URL"]
+    url = DevicehubConfig.SQLALCHEMY_DATABASE_URI
+    return 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 = get_url()
+    context.configure(url=url, target_metadata=target_metadata, literal_binds=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.
+
+    """
+    # connectable = engine_from_config(
+    #     config.get_section(config.config_ini_section),
+    #     prefix="sqlalchemy.",
+    #     poolclass=pool.NullPool,
+    # )
+
+    url = get_url()
+    connectable = create_engine(url)
+
+    with connectable.connect() as connection:
+        context.configure(connection=connection, target_metadata=target_metadata)
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

ereuse_devicehub/migrations/script.py.mako

@@ -0,0 +1,33 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from alembic import op
+import sqlalchemy as sa
+import sqlalchemy_utils
+import citext
+import teal
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
+
+
+def get_inv():
+    INV = context.get_x_argument(as_dictionary=True).get('inventory')
+    if not INV:
+        raise ValueError("Inventory value is not specified")
+    return INV
+
+def upgrade():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

requirements.txt

@@ -1,3 +1,4 @@
+alembic==1.4.2
 anytree==2.4.3
 apispec==0.39.0
 boltons==18.0.1