def prepare_database_template(self):
# --- Check template database cache ---
current_mhash = checksumdir.dirhash('./scripts/migrations')
cache_connector = db_connector(self.template_cache_name)
try:
latest_mhash = self.read_migrations_hash(cache_connector)
if latest_mhash == current_mhash:
logger.info("Using template database cache.")
# Cache is still valid, copy it to the template database
# NOTE: In theory, 'get_migrations_hash:create_database'
# should form one transaction. If another execution interrupts
# us at this point, we will be lost ... 😨
self.create_database(self.template_name,
self.template_cache_name)
return
except psycopg2.OperationalError:
pass # Database does not exist
except psycopg2.errors.UndefinedObject:
pass # No hash specified for historical reasons
# --- Cache invalidation, recreating template database ---
logger.info("Recreating template database ...")
_perform_query(f'CREATE DATABASE {self.template_name}')
connector = db_connector(self.template_name)
# Apply migrations
sp.run('./scripts/migrations/migrate.sh',
check=True,
env=dict(os.environ, POSTGRES_DB=self.template_name))
# Seal template
self.store_migrations_hash(connector, current_mhash)
connector.execute(f'''
UPDATE pg_database SET datistemplate = TRUE
WHERE datname = '{self.template_name}'
''')
logger.info("Template database was recreated.")
# --- Update cache database ---
# NOTE: In theory, this block should form one transaction. If another
# execution interrupts us at this point, we will be lost ... 😨
self.drop_database(self.template_cache_name)
self.create_database(self.template_cache_name, self.template_name)
# Copy the hash manually (not done automatically by Postgres)
self.store_migrations_hash(cache_connector, current_mhash)
logger.info("Template database was stored into cache.")
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
# Set db connection parameters using env vars
self.db_connector = _utils.db_connector()
self.host = self.db_connector.host
self.database = self.db_connector.database
self.user = self.db_connector.user
self.password = self.db_connector.password
# lazy properties
self._columns = None
self._primary_constraint_name = None
def setup_database(self):
"""
Provide throw-away database during the execution of the test case.
The database instance is created from the template which was prepared
in DatabaseTestSuite.setup_database_template().
"""
# Generate "unique" database name
outer_db = os.getenv('POSTGRES_DB')
os.environ['POSTGRES_DB'] = self.str_id
self.addCleanup(os.environ.update, POSTGRES_DB=outer_db)
# Create database
_perform_query(f'''
CREATE DATABASE {os.environ['POSTGRES_DB']}
TEMPLATE {os.environ['POSTGRES_DB_TEMPLATE']}
''')
# Instantiate connector
self.db_connector = db_connector()
# Register cleanup
self.addCleanup(_perform_query,
f'DROP DATABASE {self.db_connector.database}')
#!/usr/bin/env python3
"""
Truncate facebook posts (#213).
We want to do this because in the past, we have collected a number of old
posts that are not necessarily authored by the museum itself. To avoid wrong
is_from_museum attributions, we are going to drop all posts so that posts that
are indeed by the museum will be fetched again automatically (see #184).
"""
import logging
import os
import subprocess as sp
from _utils import db_connector, logger
CONNECTOR = db_connector()
logging.basicConfig(level=logging.INFO)
REFERENCING_TABLES = ['fb_post_comment', 'fb_post_performance']
# Are there any existing data to preserve?
if not any(
CONNECTOR.exists(f'SELECT * FROM {table}')
for table in REFERENCING_TABLES):
# Nothing to preserve, get into the fast lane
logger.info("Truncating fb_post in the fast line")
CONNECTOR.execute('''
TRUNCATE TABLE fb_post CASCADE
''')
exit(0)
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.db_connector = _utils.db_connector()