Support existing-but-not-initialized databases in init script

Since odoo/odoo@cb2862a (v12+), Odoo will not autoinitialize modules in a database that already exists.

However, in v8-, Odoo will not start if the database doesn't exist.

To make this difference easier to handle, with this change, `click-odoo-initdb` will treat non-existing databases the same as non-initialized ones (which is, for Odoo, the same).

@Tecnativa TT20713

click_odoo_contrib/_dbutils.py

@@ -8,8 +8,8 @@
 
 
 @contextmanager
-def pg_connect():
-    conn = odoo.sql_db.db_connect("postgres")
+def pg_connect(dbname="postgres"):
+    conn = odoo.sql_db.db_connect(dbname)
     cr = conn.cursor()
     cr.autocommit(True)
     try:
@@ -28,6 +28,13 @@ def db_exists(dbname):
         return bool(cr.fetchone())
 
 
+def db_initialized(dbname):
+    if not db_exists(dbname):
+        return False
+    with pg_connect(dbname) as cr:
+        return odoo.modules.db.is_initialized(cr)
+
+
 def terminate_connections(dbname):
     with pg_connect() as cr:
         cr.execute(

click_odoo_contrib/initdb.py

@@ -14,7 +14,7 @@
 import click_odoo
 from click_odoo import odoo
 
-from ._dbutils import db_exists
+from ._dbutils import db_exists, db_initialized
 from .manifest import expand_dependencies
 from .update import _save_installed_checksums
 
@@ -67,7 +67,12 @@ def _db_storage(self):
 
 def odoo_createdb(dbname, demo, module_names, force_db_storage):
     with _patch_ir_attachment_store(force_db_storage):
-        odoo.service.db._create_empty_database(dbname)
+        try:
+            odoo.service.db._create_empty_database(dbname)
+        except odoo.service.db.DatabaseExists:
+            if db_initialized(dbname):
+                # Why are you creating a DB that exists and is initialized?
+                raise
         odoo.tools.config["init"] = dict.fromkeys(module_names, 1)
         odoo.tools.config["without_demo"] = not demo
         if _odoo_version < odoo.tools.parse_version("10"):
@@ -391,6 +396,11 @@ def trim_age(self, max_age):
     is_flag=True,
     help="Don't report error if database already exists.",
 )
+@click.option(
+    "--unless-initialized",
+    is_flag=True,
+    help="Don't report error if database is already initialized.",
+)
 def main(
     env,
     new_database,
@@ -401,6 +411,7 @@ def main(
     cache_max_age,
     cache_max_size,
     unless_exists,
+    unless_initialized,
 ):
     """ Create an Odoo database with pre-installed modules.
 
@@ -419,6 +430,10 @@ def main(
         msg = "Database already exists: {}".format(new_database)
         click.echo(click.style(msg, fg="yellow"))
         return
+    if unless_initialized and db_initialized(new_database):
+        msg = "Database already initialized: {}".format(new_database)
+        click.echo(click.style(msg, fg="yellow"))
+        return
     module_names = [m.strip() for m in modules.split(",")]
     if not cache:
         if new_database: