separate paste-deploy configuration from parameters

PasteDeploy configuration contains class names which might change
between releases. Keeping it separate from user-configurable
parameters allows deployers to move paste-deploy ini file out of
configuration directory to a place where it can be safely overwritten
on updates e.g. under /usr/share/

DocImpact

Change-Id: I9292ca6226c8430b93565dedd45cc842742a23e2

1 files changed, 31 insertions, 0 deletions

diff --git a/keystone/config.py b/keystone/config.py
index e2ff6f4e..28f1cf2c 100644
--- a/keystone/config.py
+++ b/keystone/config.py
@@ -15,7 +15,10 @@
 # under the License.
 """Wrapper for keystone.common.config that configures itself on import."""
 
+import os
+
 from keystone.common import config
+from keystone import exception
 
 
 config.configure()
@@ -31,3 +34,31 @@ register_cli_bool = config.register_cli_bool
 register_int = config.register_int
 register_cli_int = config.register_cli_int
 setup_authentication = config.setup_authentication
+
+
+def find_paste_config():
+    """Selects Keystone paste.deploy configuration file.
+
+    Keystone paste.deploy configuration file is selectd in [paste_deploy]
+    section of the main Keystone configuration file.
+    For example:
+        [paste_deploy]
+        config_file = keystone-paste.ini
+
+    :returns: The selected configuration filename
+    :raises: exception.PasteConfigNotFound
+    """
+    if CONF.paste_deploy.config_file:
+        paste_config = CONF.paste_deploy.config_file
+        paste_config_value = paste_config
+        if not os.path.isabs(paste_config):
+            paste_config = CONF.find_file(paste_config)
+    elif CONF.config_file:
+        paste_config = CONF.config_file[0]
+        paste_config_value = paste_config
+    else:
+        paste_config = CONF.find_file('keystone.conf')
+        paste_config_value = 'keystone.conf'
+    if not paste_config or not os.path.exists(paste_config):
+        raise exception.PasteConfigNotFound(config_file=paste_config_value)
+    return paste_config