From bfe024288360ab8304ba374d174595fbaa839d9c Mon Sep 17 00:00:00 2001
From: Pino de Candia <giuseppe.decandia@gmail.com>
Date: Mon, 12 Mar 2018 20:30:39 +0000
Subject: [PATCH] Add API versioning.

This also fixes the openstack CLI warning:
"Failed to contact the endpoint at <...> for discovery. Fallback to using that endpoint as the base url."

Change-Id: I411b7a795ac01e050cf8162e48d1fdbdc870c8f9
Signed-off-by: Pino de Candia <giuseppe.decandia@gmail.com>
---
 devstack/plugin.sh |  3 ++-
 tatu/api/app.py    | 65 +++++++++++++++++++++++++++++++++++-----------
 tatu/config.py     |  3 +++
 3 files changed, 55 insertions(+), 16 deletions(-)

diff --git a/devstack/plugin.sh b/devstack/plugin.sh
index e1c78e3..c5d4bc3 100644
--- a/devstack/plugin.sh
+++ b/devstack/plugin.sh
@@ -54,6 +54,7 @@ function configure_tatu {
     iniset $TATU_CONF tatu sqlalchemy_engine `database_connection_url tatu`
     iniset $TATU_CONF tatu api_endpoint_for_vms $TATU_API_FOR_VMS
     iniset $TATU_CONF tatu pam_sudo True
+    iniset $TATU_CONF tatu api_base_uri $TATU_SERVICE_PROTOCOL://$TATU_SERVICE_HOST:$TATU_SERVICE_PORT/
 
     # Need Keystone and Nova notifications
     iniset $KEYSTONE_CONF oslo_messaging_notifications topics notifications,tatu_notifications
@@ -65,7 +66,7 @@ function configure_tatu {
     $TATU_DIR/scripts/cloud-config-to-vendor-data $TATU_DIR/files/user-cloud-config > $NOVA_CONF_DIR/tatu_static_vd.json
     iniset $NOVA_CONF api vendordata_providers StaticJSON,DynamicJSON
     iniset $NOVA_CONF api vendordata_jsonfile_path $NOVA_CONF_DIR/tatu_static_vd.json
-    iniset $NOVA_CONF api vendordata_dynamic_targets tatu@$TATU_SERVICE_PROTOCOL://$TATU_SERVICE_HOST:$TATU_SERVICE_PORT/novavendordata
+    iniset $NOVA_CONF api vendordata_dynamic_targets tatu@$TATU_SERVICE_PROTOCOL://$TATU_SERVICE_HOST:$TATU_SERVICE_PORT/v1/novavendordata
     iniset $NOVA_CONF api vendordata_dynamic_connect_timeout 5
     iniset $NOVA_CONF api vendordata_dynamic_read_timeout 30
     iniset $NOVA_CONF vendordata_dynamic_auth auth_url $KEYSTONE_SERVICE_URI
diff --git a/tatu/api/app.py b/tatu/api/app.py
index fb2fdd0..fedc731 100644
--- a/tatu/api/app.py
+++ b/tatu/api/app.py
@@ -14,30 +14,64 @@ import falcon
 import json
 from oslo_log import log as logging
 from tatu.api import models
+from tatu.config import CONF
 from tatu.db.persistence import SQLAlchemySessionManager
 
 LOG = logging.getLogger(__name__)
 
-class RootPage(object):
+_versions = []
+_base = CONF.tatu.api_base_uri.rstrip('/')
+
+def _version(version, status, base_uri):
+    _versions.append({
+        'id': '%s' % version,
+        'status': status,
+        'links': [{
+            'href': base_uri + '/' + version,
+            'rel': 'self'
+        }]
+    })
+
+_version('v1', 'CURRENT', _base)
+
+class Versions(object):
+
     def on_get(self, req, resp):
-        resp.body = json.dumps({})
+        body = {
+            'versions': {
+                'values': _versions
+            },
+        }
+        resp.body = json.dumps(body)
         resp.status = falcon.HTTP_OK
 
+class Version1(object):
+
+    def on_get(self, req, resp):
+        body = {
+            'version': _versions[0],
+        }
+        resp.body = json.dumps(body)
+        resp.status = falcon.HTTP_OK
+
+
 def create_app(sa):
     LOG.info("Creating falcon API instance for authenticated API calls.")
     api = falcon.API(middleware=[models.Logger(), sa])
-    api.add_route('/authorities', models.Authorities())
-    api.add_route('/authorities/{auth_id}', models.Authority())
-    api.add_route('/usercerts', models.UserCerts())
-    api.add_route('/usercerts/{serial}', models.UserCert())
-    api.add_route('/hosts', models.Hosts())
-    api.add_route('/hosts/{host_id}', models.Host())
-    api.add_route('/hostcerts', models.HostCerts())
-    api.add_route('/hostcerts/{host_id}/{fingerprint}', models.HostCert())
-    api.add_route('/hosttokens', models.Tokens())
-    api.add_route('/novavendordata', models.NovaVendorData())
-    api.add_route('/revokeduserkeys/{auth_id}', models.RevokedUserKeys())
-    api.add_route('/pats', models.PATs())
+    api.add_route('/v1/authorities', models.Authorities())
+    api.add_route('/v1/authorities/{auth_id}', models.Authority())
+    api.add_route('/v1/usercerts', models.UserCerts())
+    api.add_route('/v1/usercerts/{serial}', models.UserCert())
+    api.add_route('/v1/hosts', models.Hosts())
+    api.add_route('/v1/hosts/{host_id}', models.Host())
+    api.add_route('/v1/hostcerts', models.HostCerts())
+    api.add_route('/v1/hostcerts/{host_id}/{fingerprint}', models.HostCert())
+    api.add_route('/v1/hosttokens', models.Tokens())
+    api.add_route('/v1/novavendordata', models.NovaVendorData())
+    api.add_route('/v1/revokeduserkeys/{auth_id}', models.RevokedUserKeys())
+    api.add_route('/v1/pats', models.PATs())
+    api.add_route('/v1', Version1())
+    api.add_route('/', Versions())
     return api
 
 def create_noauth_app(sa):
@@ -45,7 +79,8 @@ def create_noauth_app(sa):
     api = falcon.API(middleware=[models.Logger(), sa])
     api.add_route('/hostcerts', models.HostCerts())
     api.add_route('/revokeduserkeys/{auth_id}', models.RevokedUserKeys())
-    api.add_route('/', RootPage())
+    api.add_route('/v1', Version1())
+    api.add_route('/', Versions())
     return api
 
 def auth_factory(global_config, **settings):
diff --git a/tatu/config.py b/tatu/config.py
index a642a2b..6a4f108 100644
--- a/tatu/config.py
+++ b/tatu/config.py
@@ -62,6 +62,9 @@ opts = [
     cfg.StrOpt('api_endpoint_for_vms',
                default='http://169.254.169.254',
                help='Where a VM accesses the API for SSH certs and revoked keys'),
+    cfg.StrOpt('api_base_uri',
+               default='http://169.254.169.254',
+               help='Base URI for version discovery.'),
 ]
 
 CONF = cfg.ConfigOpts()