[2] | 1 | import sys, os.path, logging |
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| 2 | |
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| 3 | from galaxy import eggs |
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| 4 | |
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| 5 | import pkg_resources |
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| 6 | pkg_resources.require( "sqlalchemy-migrate" ) |
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| 7 | |
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| 8 | from migrate.versioning import repository, schema |
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| 9 | from sqlalchemy import * |
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| 10 | from sqlalchemy.exc import NoSuchTableError |
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| 11 | |
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| 12 | log = logging.getLogger( __name__ ) |
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| 13 | |
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| 14 | # path relative to galaxy |
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| 15 | migrate_repository_directory = os.path.dirname( __file__ ).replace( os.getcwd() + os.path.sep, '', 1 ) |
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| 16 | migrate_repository = repository.Repository( migrate_repository_directory ) |
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| 17 | dialect_to_egg = { |
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| 18 | "sqlite" : "pysqlite>=2", |
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| 19 | "postgres" : "psycopg2", |
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| 20 | "mysql" : "MySQL_python" |
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| 21 | } |
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| 22 | |
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| 23 | def create_or_verify_database( url, engine_options={} ): |
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| 24 | """ |
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| 25 | Check that the database is use-able, possibly creating it if empty (this is |
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| 26 | the only time we automatically create tables, otherwise we force the |
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| 27 | user to do it using the management script so they can create backups). |
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| 28 | |
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| 29 | 1) Empty database --> initialize with latest version and return |
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| 30 | 2) Database older than migration support --> fail and require manual update |
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| 31 | 3) Database at state where migrate support introduced --> add version control information but make no changes (might still require manual update) |
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| 32 | 4) Database versioned but out of date --> fail with informative message, user must run "sh manage_db.sh upgrade" |
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| 33 | |
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| 34 | """ |
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| 35 | dialect = ( url.split( ':', 1 ) )[0] |
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| 36 | try: |
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| 37 | egg = dialect_to_egg[dialect] |
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| 38 | try: |
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| 39 | pkg_resources.require( egg ) |
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| 40 | log.debug( "%s egg successfully loaded for %s dialect" % ( egg, dialect ) ) |
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| 41 | except: |
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| 42 | # If the module is in the path elsewhere (i.e. non-egg), it'll still load. |
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| 43 | log.warning( "%s egg not found, but an attempt will be made to use %s anyway" % ( egg, dialect ) ) |
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| 44 | except KeyError: |
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| 45 | # Let this go, it could possibly work with db's we don't support |
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| 46 | log.error( "database_connection contains an unknown SQLAlchemy database dialect: %s" % dialect ) |
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| 47 | # Create engine and metadata |
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| 48 | engine = create_engine( url, **engine_options ) |
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| 49 | meta = MetaData( bind=engine ) |
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| 50 | # Try to load dataset table |
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| 51 | try: |
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| 52 | galaxy_user_table = Table( "galaxy_user", meta, autoload=True ) |
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| 53 | except NoSuchTableError: |
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| 54 | # No 'galaxy_user' table means a completely uninitialized database, which |
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| 55 | # is fine, init the database in a versioned state |
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| 56 | log.info( "No database, initializing" ) |
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| 57 | # Database might or might not be versioned |
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| 58 | try: |
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| 59 | # Declare the database to be under a repository's version control |
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| 60 | db_schema = schema.ControlledSchema.create( engine, migrate_repository ) |
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| 61 | except: |
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| 62 | # The database is already under version control |
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| 63 | db_schema = schema.ControlledSchema( engine, migrate_repository ) |
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| 64 | # Apply all scripts to get to current version |
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| 65 | migrate_to_current_version( engine, db_schema ) |
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| 66 | return |
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| 67 | try: |
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| 68 | version_table = Table( "migrate_version", meta, autoload=True ) |
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| 69 | except NoSuchTableError: |
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| 70 | # The database exists but is not yet under migrate version control, so init with version 1 |
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| 71 | log.info( "Adding version control to existing database" ) |
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| 72 | try: |
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| 73 | metadata_file_table = Table( "metadata_file", meta, autoload=True ) |
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| 74 | schema.ControlledSchema.create( engine, migrate_repository, version=2 ) |
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| 75 | except NoSuchTableError: |
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| 76 | schema.ControlledSchema.create( engine, migrate_repository, version=1 ) |
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| 77 | # Verify that the code and the DB are in sync |
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| 78 | db_schema = schema.ControlledSchema( engine, migrate_repository ) |
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| 79 | if migrate_repository.versions.latest != db_schema.version: |
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| 80 | raise Exception( "Your database has version '%d' but this code expects version '%d'. Please backup your database and then migrate the schema by running 'sh manage_db.sh upgrade'." |
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| 81 | % ( db_schema.version, migrate_repository.versions.latest ) ) |
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| 82 | else: |
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| 83 | log.info( "At database version %d" % db_schema.version ) |
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| 84 | |
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| 85 | def migrate_to_current_version( engine, schema ): |
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| 86 | # Changes to get to current version |
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| 87 | changeset = schema.changeset( None ) |
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| 88 | for ver, change in changeset: |
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| 89 | nextver = ver + changeset.step |
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| 90 | log.info( 'Migrating %s -> %s... ' % ( ver, nextver ) ) |
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| 91 | old_stdout = sys.stdout |
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| 92 | class FakeStdout( object ): |
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| 93 | def __init__( self ): |
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| 94 | self.buffer = [] |
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| 95 | def write( self, s ): |
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| 96 | self.buffer.append( s ) |
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| 97 | def flush( self ): |
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| 98 | pass |
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| 99 | sys.stdout = FakeStdout() |
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| 100 | try: |
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| 101 | schema.runchange( ver, change, changeset.step ) |
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| 102 | finally: |
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| 103 | for message in "".join( sys.stdout.buffer ).split( "\n" ): |
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| 104 | log.info( message ) |
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| 105 | sys.stdout = old_stdout |
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