Alembic beginnings

mishmash/alembic.ini

@@ -0,0 +1,68 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = alembic
+
+# template used to generate migration files
+# file_template = %%(rev)s_%%(slug)s
+
+# 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 = sqlite:///testdb.sql
+
+
+# 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

mishmash/alembic/README

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

mishmash/alembic/env.py

@@ -0,0 +1,70 @@
+from __future__ import with_statement
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+from logging.config import fileConfig
+
+# 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
+
+# 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 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)
+
+    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)
+
+    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()

mishmash/alembic/script.py.mako

@@ -0,0 +1,24 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from alembic import op
+import sqlalchemy as sa
+${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 upgrade():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

mishmash/alembic/versions/ae1461b8a01f_initial_empty_rev.py

@@ -0,0 +1,24 @@
+"""initial/empty rev
+
+Revision ID: ae1461b8a01f
+Revises: 
+Create Date: 2017-01-22 00:14:12.583177
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'ae1461b8a01f'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    pass
+
+
+def downgrade():
+    pass

mishmash/database.py

@@ -1,10 +1,14 @@
+import os
+from pathlib import Path
 import nicfit
 from sqlalchemy import create_engine, or_
 from sqlalchemy.orm import sessionmaker
 
 from sqlalchemy_utils.functions import (database_exists,
                                         create_database,
                                         drop_database)
+from alembic import command
+from alembic.config import Config
 
 from .orm import TYPES, TABLES
 from .orm import Base, Artist, Track, Album
@@ -20,16 +24,16 @@
 
 
 def init(config, engine_args=None, session_args=None, trans_mgr=None):
-    url = config.db_url
+    db_url = config.db_url
 
-    log.debug("Checking for database '%s'" % url)
-    if not database_exists(url):
-        log.info("Creating database '%s'" % url)
-        create_database(url, template="template0")
+    log.debug("Checking for database '%s'" % db_url)
+    if not database_exists(db_url):
+        log.info("Creating database '%s'" % db_url)
+        create_database(db_url, template="template0")
 
-    log.debug("Connecting to database '%s'" % url)
+    log.debug("Connecting to database '%s'" % db_url)
     args = engine_args or DEFAULT_ENGINE_ARGS
-    engine = create_engine(url, **args)
+    engine = create_engine(db_url, **args)
     engine.connect()
 
     args = session_args or DEFAULT_SESSION_ARGS
@@ -42,17 +46,20 @@ def init(config, engine_args=None, session_args=None, trans_mgr=None):
         T.metadata.bind = engine
 
     session = SessionMaker()
+    alembic_init = False
     try:
         try:
-            log.debug("Checking database schema '%s'" % url)
+            log.debug("Checking database schema '%s'" % db_url)
             checkSchema(engine)
         except MissingSchemaException as ex:
-            log.info("Creating database schema '%s'" % url)
+            log.info("Creating database schema '%s'" % db_url)
             Base.metadata.create_all(engine)
             for T in TYPES:
                 # Run extra table initialization
                 T.initTable(session, config)
 
+            alembic_init = True
+
         if trans_mgr:
             transaction.commit()
         else:
@@ -66,6 +73,17 @@ def init(config, engine_args=None, session_args=None, trans_mgr=None):
     finally:
         session.close()
 
+    if alembic_init:
+        alembic_d = Path(__file__).parent
+        alembic_cfg = Config(str(alembic_d / "alembic.ini"))
+        alembic_cfg.set_main_option("sqlalchemy.url", db_url)
+        cwd = os.getcwd()
+        try:
+            os.chdir(str(alembic_d))
+            command.stamp(alembic_cfg, "head")
+        finally:
+            os.chdir(cwd)
+
     return engine, SessionMaker