port database setup function to python

Hide the former PHP functions in a transition command until
they are removed.

nominatim/tools/database_import.py

@@ -0,0 +1,121 @@
+"""
+Functions for setting up and importing a new Nominatim database.
+"""
+import logging
+import subprocess
+import shutil
+
+from ..db.connection import connect, get_pg_env
+from ..db import utils as db_utils
+from ..errors import UsageError
+from ..version import POSTGRESQL_REQUIRED_VERSION, POSTGIS_REQUIRED_VERSION
+
+LOG = logging.getLogger()
+
+def create_db(dsn, rouser=None):
+    """ Create a new database for the given DSN. Fails when the database
+        already exists or the PostgreSQL version is too old.
+        Uses `createdb` to create the database.
+
+        If 'rouser' is given, then the function also checks that the user
+        with that given name exists.
+
+        Requires superuser rights by the caller.
+    """
+    proc = subprocess.run(['createdb'], env=get_pg_env(dsn), check=False)
+
+    if proc.returncode != 0:
+        raise UsageError('Creating new database failed.')
+
+    with connect(dsn) as conn:
+        postgres_version = conn.server_version_tuple() # pylint: disable=E1101
+        if postgres_version < POSTGRESQL_REQUIRED_VERSION:
+            LOG.fatal('Minimum supported version of Postgresql is %d.%d. '
+                      'Found version %d.%d.',
+                      POSTGRESQL_REQUIRED_VERSION[0], POSTGRESQL_REQUIRED_VERSION[1],
+                      postgres_version[0], postgres_version[1])
+            raise UsageError('PostgreSQL server is too old.')
+
+        if rouser is not None:
+            with conn.cursor() as cur:  # pylint: disable=E1101
+                cnt = cur.scalar('SELECT count(*) FROM pg_user where usename = %s',
+                                 (rouser, ))
+                if cnt == 0:
+                    LOG.fatal("Web user '%s' does not exists. Create it with:\n"
+                              "\n      createuser %s", rouser, rouser)
+                    raise UsageError('Missing read-only user.')
+
+
+
+def setup_extensions(conn):
+    """ Set up all extensions needed for Nominatim. Also checks that the
+        versions of the extensions are sufficient.
+    """
+    with conn.cursor() as cur:
+        cur.execute('CREATE EXTENSION IF NOT EXISTS hstore')
+        cur.execute('CREATE EXTENSION IF NOT EXISTS postgis')
+    conn.commit()
+
+    postgis_version = conn.postgis_version_tuple()
+    if postgis_version < POSTGIS_REQUIRED_VERSION:
+        LOG.fatal('Minimum supported version of PostGIS is %d.%d. '
+                  'Found version %d.%d.',
+                  POSTGIS_REQUIRED_VERSION[0], POSTGIS_REQUIRED_VERSION[1],
+                  postgis_version[0], postgis_version[1])
+        raise UsageError('PostGIS version is too old.')
+
+
+def install_module(src_dir, project_dir, module_dir):
+    """ Copy the normalization module from src_dir into the project
+        directory under the '/module' directory. If 'module_dir' is set, then
+        use the module from there instead and check that it is accessible
+        for Postgresql.
+
+        The function detects when the installation is run from the
+        build directory. It doesn't touch the module in that case.
+    """
+    if not module_dir:
+        module_dir = project_dir / 'module'
+
+        if not module_dir.exists() or not src_dir.samefile(module_dir):
+
+            if not module_dir.exists():
+                module_dir.mkdir()
+
+            destfile = module_dir / 'nominatim.so'
+            shutil.copy(str(src_dir / 'nominatim.so'), str(destfile))
+            destfile.chmod(0o755)
+
+            LOG.info('Database module installed at %s', str(destfile))
+        else:
+            LOG.info('Running from build directory. Leaving database module as is.')
+    else:
+        LOG.info("Using custom path for database module at '%s'", module_dir)
+
+    return module_dir
+
+
+def check_module_dir_path(conn, path):
+    """ Check that the normalisation module can be found and executed
+        from the given path.
+    """
+    with conn.cursor() as cur:
+        cur.execute("""CREATE FUNCTION nominatim_test_import_func(text)
+                       RETURNS text AS '{}/nominatim.so', 'transliteration'
+                       LANGUAGE c IMMUTABLE STRICT;
+                       DROP FUNCTION nominatim_test_import_func(text)
+                    """.format(path))
+
+
+def import_base_data(dsn, sql_dir, ignore_partitions=False):
+    """ Create and populate the tables with basic static data that provides
+        the background for geocoding.
+    """
+    db_utils.execute_file(dsn, sql_dir / 'country_name.sql')
+    db_utils.execute_file(dsn, sql_dir / 'country_osm_grid.sql.gz')
+
+    if ignore_partitions:
+        with connect(dsn) as conn:
+            with conn.cursor() as cur:  # pylint: disable=E1101
+                cur.execute('UPDATE country_name SET partition = 0')
+            conn.commit()  # pylint: disable=E1101