Merge pull request #37 from blue-yonder/development_nndo1991

Prevent delete operation if there are active sessions in DB

.gitignore

@@ -38,3 +38,5 @@ docs/api/*
 docs/_build/*
 cover/*
 MANIFEST
+pyvenv.cfg
+application.cfg

README.rst

@@ -60,7 +60,7 @@ now your instance is created and as a response you get the details of your insta
          "postgraas_instance_id": 1,
          "container_id": "193f0d94d49fa26626fdbdb583e9453f923468b01eac59207b4852831a105c03",
          "db_pwd": "secret",
-         "host": "not imlemented yet",
+         "host": "not implemented yet",
          "db_name": "my_db",
          "db_username": "db_user",
          "port": 54648
@@ -75,27 +75,94 @@ Awesome, isn’t it?
 Development
 ===========
 
-Run the tests
--------------
+You can follow the next steps in order to host postgraas_server locally and be able to develop features or bug fixes:
 
-You need to have docker installed
+Clone repository::
 
-Make sure you pull the right docker image::
+    git clone https://github.com/blue-yonder/postgraas_server
 
-    docker pull postgres:9.4
-
-Make a virtualenv and install the requirements including the dev requirements and a local editable install
-of the package, for convenience you can install the requirements.in ::
+Install all the project dependencies::
 
-    pip install -r requirements.in
     pip install -r requirements_dev.txt
+    pip install -r requirements_docker.in
+    pip install -r requirements_prometheus.in 
+    pip install gunicorn
     pip install -e .
 
-For the tests you need a running postgres meta database and set some environment variables accordingly.
-There is a convenience script to set this all up using a docker postgres database::
+Docker
+-----------------
+
+Pull the right docker image::
+
+    docker pull postgres:9.4
+
+Your application.cfg file should look like this::
+
+    {
+        "metadb":
+        {
+            "db_name": "postgres",
+            "db_username": "postgres",
+            "db_pwd": "mysecret",
+            "host": "localhost",
+            "port": "5432"
+        },
+        "backend":
+        {
+            "type": "docker"
+        }
+    }
+
+Initialize a postgres DB within a docker container::
+
+    sh setup_integration_test_docker.sh
+
+Run a Docker container with the postgres image::
+
+    postgraas_init
+
+Postgres Cluster
+-----------------
+
+If you don't want to use Docker as the backend you could create a local postgres cluster
+
+Your application.cfg file should look like this::
+
+    {
+        "metadb":
+        {
+            "db_name": "postgres",
+            "db_username": "postgres",
+            "db_pwd": "mysecret",
+            "host": "localhost",
+            "port": "5432"
+        },
+        "backend":
+        {
+            "type": "pg_cluster",
+            "database": "postgres",
+            "username": "postgres",
+            "password": "mysecret",
+            "host": "localhost",
+            "port": "5432"
+        }
+    }
+
+Run postgres server::
+
+    postgres -D /usr/local/var/postgres
+
+Execute application locally
+-----------------
+
+Run the Flask application by executing this command::
+
+    python postgraas_server/postgraas_api.py
+
+After this your application should be started and you can perform GET/POST/DELETE actions to this endppoint::
 
-    . setup_integration_test_docker.sh
+    http://localhost:5000/api/v2/postgraas_instances
 
-Now you should be able to execute the tests::
+Alternatively, you can run your unit and integration tests to verify your new code::
 
     pytest tests/

docs/conf.py

@@ -45,7 +45,7 @@
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
 extensions = ['sphinx.ext.autodoc', 'sphinx.ext.intersphinx', 'sphinx.ext.todo',
               'sphinx.ext.autosummary', 'sphinx.ext.viewcode', 'sphinx.ext.coverage',
-              'sphinx.ext.doctest', 'sphinx.ext.ifconfig', 'sphinx.ext.pngmath',
+              'sphinx.ext.doctest', 'sphinx.ext.ifconfig', 'sphinx.ext.imgmath',
               'sphinx.ext.napoleon']
 
 # Add any paths that contain templates here, relative to this directory.

postgraas_server/backends/docker/postgres_instance_driver.py

@@ -3,7 +3,7 @@
 
 def get_hostname():
     # mmmh, how should this be done? need nome kind ouf routing...
-    return 'not imlemented yet'
+    return 'not implemented yet'
 
 
 def _docker_client():

postgraas_server/management_resources.py

@@ -7,6 +7,7 @@
 from flask_sqlalchemy import SQLAlchemy
 
 from postgraas_server.backends.exceptions import PostgraasApiException
+from contextlib import closing
 
 logger = logging.getLogger(__name__)
 
@@ -75,24 +76,27 @@ def delete(self, id):
 
         entity = DBInstance.query.get(id)
         if not entity:
-            abort(404, status='failed',
-                  msg='Postgraas instance {} does not exist'.format(id)
-                  )
+            abort(404, status='failed', msg='Postgraas instance {} does not exist'.format(id))
+
+        other_sessions = 0
 
         try:
-            with psycopg2.connect(
+            with closing(psycopg2.connect(
                     user=entity.username,
                     password=args['db_pwd'],
                     host=current_app.postgraas_backend.master_hostname,
                     port=entity.port,
                     dbname=entity.db_name
-            ):
-                pass
+            )) as conn:
+                cur = conn.cursor()
+                cur.execute("select count(pid) from pg_stat_activity where datname = %s ;", (entity.db_name,))
+                other_sessions = cur.fetchone()[0]-1
         except Exception as ex:
             return_code = 401 if 'authentication failed' in str(ex) else 500
-            abort(return_code, status='failed',
-                  msg='Could not connect to postgres instance: {}'.format(str(ex))
-                  )
+            abort(return_code, status='failed', msg='Could not connect to postgres instance: {}'.format(str(ex)))
+
+        if other_sessions > 0:
+            abort(409, status='failed', msg='Database contains other {} active sessions. Please close or terminate all sessions before deleting'.format(other_sessions))
 
         if not current_app.postgraas_backend.exists(entity):
             logger.warning(

setup_integration_test_docker.sh

@@ -1,9 +1,9 @@
 #!/usr/bin/env bash
 ## I hate setup bash scripts...but this one sets up a local postgres cluster for the postgres cluster backend...quite handy...
 export PGDATABASE=postgres
-export PGUSER=postgres@localhost
+export PGUSER=postgres
 export PGPASSWORD=mysecret
-export PGPORT=54320
+export PGPORT=5432
 export PGHOST=localhost
 
 docker run --name some-postgres -e POSTGRES_PASSWORD=$PGPASSWORD -e POSTGRES_USER=$PGUSER -e POSTGRES_DB=$PGDATABASE -p $PGPORT:5432 -d postgres

tests/test_integration/test_postgraas_api.py

@@ -4,7 +4,9 @@
 
 import docker
 import pytest
+import psycopg2
 from mock import patch, MagicMock, Mock
+from contextlib import closing
 
 import postgraas_server.backends.docker.postgres_instance_driver as pid
 import postgraas_server.backends.postgres_cluster.postgres_cluster_driver as pgcd
@@ -402,6 +404,59 @@ def test_delete_notfound(self):
         assert res['status'] == 'failed'
         assert "123456789" in res['msg'], 'unexpected error message'
 
+    def test_delete_postgres_instance_api_with_active_sessions(self):
+        db_credentials = {
+            "postgraas_instance_name": "test_active_sessions_instance",
+            "db_name": "test_active_sessions_db",
+            "db_username": "test_active_sessions_user",
+            "db_pwd": "secret"
+        }
+        headers = {'Content-Type': 'application/json'}
+        result = self.app_client.post(
+            '/api/v2/postgraas_instances', headers=headers, data=json.dumps(db_credentials)
+        )
+        created_db = json.loads(result.get_data(as_text=True))
+
+        if self.backend == 'docker':
+            wait_success = wait_for_postgres_listening(created_db['container_id'])
+            assert wait_success is True, 'postgres did not come up within 10s (or unexpected docker image log output)'
+
+        try:
+            with closing(psycopg2.connect(
+                    user=db_credentials["db_username"],
+                    password=db_credentials["db_pwd"],
+                    host=os.environ.get('PGHOST', 'localhost'),
+                    port=created_db["port"],
+                    dbname=db_credentials["db_name"]
+            )):
+                delete_result = self.app_client.delete(
+                    '/api/v2/postgraas_instances/' + str(created_db["postgraas_instance_id"]),
+                    data=json.dumps({
+                        'db_pwd': db_credentials['db_pwd']
+                    }),
+                    headers=headers
+                )
+                deleted_db = json.loads(delete_result.get_data(as_text=True))
+                assert delete_result.status_code == 409
+                assert deleted_db["status"] == 'failed'
+                assert 'active sessions' in deleted_db[
+                    'msg'
+                ], 'unexpected message for active sessions in the database'
+        except Exception:
+            pass
+
+        delete_result = self.app_client.delete(
+            '/api/v2/postgraas_instances/' + str(created_db["postgraas_instance_id"]),
+            data=json.dumps({
+                'db_pwd': db_credentials['db_pwd']
+            }),
+            headers=headers
+        )
+
+        deleted_db = json.loads(delete_result.get_data(as_text=True))
+        assert delete_result.status_code == 200
+        assert deleted_db["status"] == 'success'
+
     def test_create_postgres_instance_name_exists(self):
         db_credentials = {
             "postgraas_instance_name": "tests_postgraas_my_postgraas_twice",