refactor: Compatibility with Neo4J 4.0.4 (4.x in general should work) (…

…#270)

* Compatibility with latest Neo4J 4.0.4

Starting with Neo4J v4, it no longer auto generates SSL/TLS
certificates if they aren't supplied. To keep the example
working, I needed config to specify whether the connection
to Neo4J should be encrypted or not.

It defaults to False, at the moment, so I think most
people would need to add an explicit True to their config.

* Satisfy warning and fix test failures.

The neo4j driver is now supposed to be imported using 'neo4j', the
older .v1 is now deprecated. I was going to leave this, but then
saw there are deprecation warnings.

Several unit tests were failing because they new 'neo4j_encrypted'
key wasn't included in the configs. I believe it makes sense to
include 'NEO4J_ENCRYPTED: True' as a default anyway. This should
stop people with existing configs from having to update them.

* Add a config parameter for SSL cert validation.

README.md

@@ -351,11 +351,12 @@ An extractor that basically get current timestamp and passes it GenericExtractor
 An extractor that extracts records from Neo4j based on provided [Cypher query](https://neo4j.com/developer/cypher/ "Cypher query"). One example is to extract data from Neo4j so that it can transform and publish to Elasticsearch.
 ```python
 job_config = ConfigFactory.from_dict({
-	'extractor.neo4j.{}'.format(Neo4jExtractor.CYPHER_QUERY_CONFIG_KEY)': cypher_query,
+	'extractor.neo4j.{}'.format(Neo4jExtractor.CYPHER_QUERY_CONFIG_KEY): cypher_query,
 	'extractor.neo4j.{}'.format(Neo4jExtractor.GRAPH_URL_CONFIG_KEY): neo4j_endpoint,
 	'extractor.neo4j.{}'.format(Neo4jExtractor.MODEL_CLASS_CONFIG_KEY): 'package.module.class_name',
 	'extractor.neo4j.{}'.format(Neo4jExtractor.NEO4J_AUTH_USER): neo4j_user,
-	'extractor.neo4j.{}'.format(Neo4jExtractor.NEO4J_AUTH_PW): neo4j_password})
+	'extractor.neo4j.{}'.format(Neo4jExtractor.NEO4J_AUTH_PW): neo4j_password},
+	'extractor.neo4j.{}'.format(Neo4jExtractor.NEO4J_ENCRYPTED): True})
 job = DefaultJob(
 	conf=job_config,
 	task=DefaultTask(
@@ -370,7 +371,8 @@ job_config = ConfigFactory.from_dict({
 	'extractor.search_data.extractor.neo4j.{}'.format(Neo4jExtractor.GRAPH_URL_CONFIG_KEY): neo4j_endpoint,
 	'extractor.search_data.extractor.neo4j.{}'.format(Neo4jExtractor.MODEL_CLASS_CONFIG_KEY): 'databuilder.models.neo4j_data.Neo4jDataResult',
 	'extractor.search_data.extractor.neo4j.{}'.format(Neo4jExtractor.NEO4J_AUTH_USER): neo4j_user,
-	'extractor.search_data.extractor.neo4j.{}'.format(Neo4jExtractor.NEO4J_AUTH_PW): neo4j_password})
+	'extractor.search_data.extractor.neo4j.{}'.format(Neo4jExtractor.NEO4J_AUTH_PW): neo4j_password},
+	'extractor.search_data.extractor.neo4j.{}'.format(Neo4jExtractor.NEO4J_ENCRYPTED): False})
 job = DefaultJob(
 	conf=job_config,
 	task=DefaultTask(
@@ -444,6 +446,7 @@ job_config = ConfigFactory.from_dict({
 	'publisher.neo4j.{}'.format(neo4j_csv_publisher.NEO4J_END_POINT_KEY): neo4j_endpoint,
 	'publisher.neo4j.{}'.format(neo4j_csv_publisher.NEO4J_USER): neo4j_user,
 	'publisher.neo4j.{}'.format(neo4j_csv_publisher.NEO4J_PASSWORD): neo4j_password,
+	'publisher.neo4j.{}'.format(neo4j_csv_publisher.NEO4J_ENCRYPTED): True,
 	'publisher.neo4j.{}'.format(neo4j_csv_publisher.NEO4J_CREATE_ONLY_NODES): [DESCRIPTION_NODE_LABEL],
 	'publisher.neo4j.{}'.format(neo4j_csv_publisher.JOB_PUBLISH_TAG): job_publish_tag
 })
@@ -698,7 +701,8 @@ job_config = ConfigFactory.from_dict({
 	'publisher.neo4j.{}'.format(neo4j_csv_publisher.RELATION_FILES_DIR): relationship_files_folder,
 	'publisher.neo4j.{}'.format(neo4j_csv_publisher.NEO4J_END_POINT_KEY): neo4j_endpoint,
 	'publisher.neo4j.{}'.format(neo4j_csv_publisher.NEO4J_USER): neo4j_user,
-	'publisher.neo4j.{}'.format(neo4j_csv_publisher.NEO4J_PASSWORD): neo4j_password,})
+	'publisher.neo4j.{}'.format(neo4j_csv_publisher.NEO4J_PASSWORD): neo4j_password,
+	'publisher.neo4j.{}'.format(neo4j_csv_publisher.NEO4J_ENCRYPTED): True})
 
 job = DefaultJob(
 	conf=job_config,

databuilder/extractor/neo4j_extractor.py

@@ -3,7 +3,8 @@
 from typing import Any, Iterator, Union  # noqa: F401
 
 from pyhocon import ConfigTree, ConfigFactory  # noqa: F401
-from neo4j.v1 import GraphDatabase
+from neo4j import GraphDatabase
+import neo4j
 
 from databuilder.extractor.base_extractor import Extractor
 
@@ -20,8 +21,14 @@ class Neo4jExtractor(Extractor):
     NEO4J_AUTH_USER = 'neo4j_auth_user'
     NEO4J_AUTH_PW = 'neo4j_auth_pw'
     NEO4J_MAX_CONN_LIFE_TIME_SEC = 'neo4j_max_conn_life_time_sec'
+    NEO4J_ENCRYPTED = 'neo4j_encrypted'
+    """NEO4J_ENCRYPTED is a boolean indicating whether to use SSL/TLS when connecting."""
+    NEO4J_VALIDATE_SSL = 'neo4j_validate_ssl'
+    """NEO4J_VALIDATE_SSL is a boolean indicating whether to validate the server's SSL/TLS cert against system CAs."""
 
-    DEFAULT_CONFIG = ConfigFactory.from_dict({NEO4J_MAX_CONN_LIFE_TIME_SEC: 50, })
+    DEFAULT_CONFIG = ConfigFactory.from_dict({NEO4J_MAX_CONN_LIFE_TIME_SEC: 50,
+                                              NEO4J_ENCRYPTED: True,
+                                              NEO4J_VALIDATE_SSL: False})
 
     def init(self, conf):
         # type: (ConfigTree) -> None
@@ -57,11 +64,15 @@ def _get_driver(self):
         """
         Create a Neo4j connection to Database
         """
+        trust = neo4j.TRUST_SYSTEM_CA_SIGNED_CERTIFICATES if self.conf.get_bool(Neo4jExtractor.NEO4J_VALIDATE_SSL) \
+            else neo4j.TRUST_ALL_CERTIFICATES
         return GraphDatabase.driver(self.graph_url,
                                     max_connection_life_time=self.conf.get_int(
                                         Neo4jExtractor.NEO4J_MAX_CONN_LIFE_TIME_SEC),
                                     auth=(self.conf.get_string(Neo4jExtractor.NEO4J_AUTH_USER),
-                                          self.conf.get_string(Neo4jExtractor.NEO4J_AUTH_PW)))
+                                          self.conf.get_string(Neo4jExtractor.NEO4J_AUTH_PW)),
+                                    encrypted=self.conf.get_bool(Neo4jExtractor.NEO4J_ENCRYPTED),
+                                    trust=trust)
 
     def _execute_query(self, tx):
         # type: (Any) -> Any

databuilder/publisher/neo4j_csv_publisher.py

@@ -9,7 +9,9 @@
 from string import Template
 
 import six
-from neo4j.v1 import GraphDatabase, Transaction  # noqa: F401
+from neo4j import GraphDatabase, Transaction  # noqa: F401
+import neo4j
+from neo4j.exceptions import CypherError
 from pyhocon import ConfigFactory  # noqa: F401
 from pyhocon import ConfigTree  # noqa: F401
 from typing import Set, List  # noqa: F401
@@ -44,6 +46,10 @@
 
 NEO4J_USER = 'neo4j_user'
 NEO4J_PASSWORD = 'neo4j_password'
+NEO4J_ENCRYPTED = 'neo4j_encrypted'
+"""NEO4J_ENCRYPTED is a boolean indicating whether to use SSL/TLS when connecting."""
+NEO4J_VALIDATE_SSL = 'neo4j_validate_ssl'
+"""NEO4J_VALIDATE_SSL is a boolean indicating whether to validate the server's SSL/TLS cert against system CAs."""
 
 # This will be used to provide unique tag to the node and relationship
 JOB_PUBLISH_TAG = 'job_publish_tag'
@@ -88,6 +94,8 @@
                                           NEO4J_PROGRESS_REPORT_FREQUENCY: 500,
                                           NEO4J_RELATIONSHIP_CREATION_CONFIRM: False,
                                           NEO4J_MAX_CONN_LIFE_TIME_SEC: 50,
+                                          NEO4J_ENCRYPTED: True,
+                                          NEO4J_VALIDATE_SSL: False,
                                           RELATION_PREPROCESSOR: NoopRelationPreprocessor()})
 
 NODE_MERGE_TEMPLATE = Template("""MERGE (node:$LABEL {key: '${KEY}'})
@@ -133,10 +141,14 @@ def init(self, conf):
         self._relation_files = self._list_files(conf, RELATION_FILES_DIR)
         self._relation_files_iter = iter(self._relation_files)
 
+        trust = neo4j.TRUST_SYSTEM_CA_SIGNED_CERTIFICATES if conf.get_bool(NEO4J_VALIDATE_SSL) \
+            else neo4j.TRUST_ALL_CERTIFICATES
         self._driver = \
             GraphDatabase.driver(conf.get_string(NEO4J_END_POINT_KEY),
                                  max_connection_life_time=conf.get_int(NEO4J_MAX_CONN_LIFE_TIME_SEC),
-                                 auth=(conf.get_string(NEO4J_USER), conf.get_string(NEO4J_PASSWORD)))
+                                 auth=(conf.get_string(NEO4J_USER), conf.get_string(NEO4J_PASSWORD)),
+                                 encrypted=conf.get_bool(NEO4J_ENCRYPTED),
+                                 trust=trust)
         self._transaction_size = conf.get_int(NEO4J_TRANSCATION_SIZE)
         self._session = self._driver.session()
         self._confirm_rel_created = conf.get_bool(NEO4J_RELATIONSHIP_CREATION_CONFIRM)
@@ -451,12 +463,17 @@ def _try_create_index(self,
         # type: (str) -> None
         """
         For any label seen first time for this publisher it will try to create unique index.
-        There's no side effect on Neo4j side issuing index creation for existing index.
+        Neo4j ignores a second creation in 3.x, but raises an error in 4.x.
         :param label:
         :return:
         """
         stmt = CREATE_UNIQUE_INDEX_TEMPLATE.substitute(LABEL=label)
         LOGGER.info('Trying to create index for label {label} if not exist: {stmt}'.format(label=label,
                                                                                            stmt=stmt))
         with self._driver.session() as session:
-            session.run(stmt)
+            try:
+                session.run(stmt)
+            except CypherError as e:
+                if 'An equivalent constraint already exists' not in e.__str__():
+                    raise
+                # Else, swallow the exception, to make this function idempotent.

databuilder/task/neo4j_staleness_removal_task.py

@@ -3,6 +3,7 @@
 import time
 
 from neo4j import GraphDatabase  # noqa: F401
+import neo4j
 from pyhocon import ConfigFactory  # noqa: F401
 from pyhocon import ConfigTree  # noqa: F401
 from typing import Dict, Iterable, Any  # noqa: F401
@@ -16,6 +17,10 @@
 NEO4J_MAX_CONN_LIFE_TIME_SEC = 'neo4j_max_conn_life_time_sec'
 NEO4J_USER = 'neo4j_user'
 NEO4J_PASSWORD = 'neo4j_password'
+NEO4J_ENCRYPTED = 'neo4j_encrypted'
+"""NEO4J_ENCRYPTED is a boolean indicating whether to use SSL/TLS when connecting."""
+NEO4J_VALIDATE_SSL = 'neo4j_validate_ssl'
+"""NEO4J_VALIDATE_SSL is a boolean indicating whether to validate the server's SSL/TLS cert against system CAs."""
 
 TARGET_NODES = "target_nodes"
 TARGET_RELATIONS = "target_relations"
@@ -31,6 +36,8 @@
 
 DEFAULT_CONFIG = ConfigFactory.from_dict({BATCH_SIZE: 100,
                                           NEO4J_MAX_CONN_LIFE_TIME_SEC: 50,
+                                          NEO4J_ENCRYPTED: True,
+                                          NEO4J_VALIDATE_SSL: False,
                                           STALENESS_MAX_PCT: 5,
                                           TARGET_NODES: [],
                                           TARGET_RELATIONS: [],
@@ -85,10 +92,14 @@ def init(self, conf):
         else:
             self.marker = conf.get_string(JOB_PUBLISH_TAG)
 
+        trust = neo4j.TRUST_SYSTEM_CA_SIGNED_CERTIFICATES if conf.get_bool(NEO4J_VALIDATE_SSL) \
+            else neo4j.TRUST_ALL_CERTIFICATES
         self._driver = \
             GraphDatabase.driver(conf.get_string(NEO4J_END_POINT_KEY),
                                  max_connection_life_time=conf.get_int(NEO4J_MAX_CONN_LIFE_TIME_SEC),
-                                 auth=(conf.get_string(NEO4J_USER), conf.get_string(NEO4J_PASSWORD)))
+                                 auth=(conf.get_string(NEO4J_USER), conf.get_string(NEO4J_PASSWORD)),
+                                 encrypted=conf.get_bool(NEO4J_ENCRYPTED),
+                                 trust=trust)
 
     def run(self):
         # type: () -> None

docs/dashboard_ingestion_guide.md

@@ -78,6 +78,8 @@ job_config = ConfigFactory.from_dict({
         neo4j_user,
     'extractor.search_data.extractor.neo4j.{}'.format(Neo4jExtractor.NEO4J_AUTH_PW):
         neo4j_password,
+    'extractor.search_data.extractor.neo4j.{}'.format(Neo4jExtractor.NEO4J_ENCRYPTED):
+        False,
     'extractor.search_data.{}'.format(Neo4jSearchDataExtractor.CYPHER_QUERY_CONFIG_KEY):
         Neo4jSearchDataExtractor.DEFAULT_NEO4J_DASHBOARD_CYPHER_QUERY,
     'extractor.search_data.{}'.format(neo4j_csv_publisher.JOB_PUBLISH_TAG):

example/scripts/sample_data_loader.py

@@ -92,6 +92,7 @@ def run_csv_job(file_loc, table_name, model):
         'publisher.neo4j.neo4j_endpoint': neo4j_endpoint,
         'publisher.neo4j.neo4j_user': neo4j_user,
         'publisher.neo4j.neo4j_password': neo4j_password,
+        'publisher.neo4j.neo4j_encrypted': False,
         'publisher.neo4j.job_publish_tag': 'unique_tag',  # should use unique tag here like {ds}
     })
 
@@ -120,6 +121,7 @@ def run_table_column_job(table_path, column_path):
         'publisher.neo4j.neo4j_endpoint': neo4j_endpoint,
         'publisher.neo4j.neo4j_user': neo4j_user,
         'publisher.neo4j.neo4j_password': neo4j_password,
+        'publisher.neo4j.neo4j_encrypted': False,
         'publisher.neo4j.job_publish_tag': 'unique_tag',  # should use unique tag here like {ds}
     })
     job = DefaultJob(conf=job_config,
@@ -148,6 +150,7 @@ def create_last_updated_job():
         'publisher.neo4j.neo4j_endpoint': neo4j_endpoint,
         'publisher.neo4j.neo4j_user': neo4j_user,
         'publisher.neo4j.neo4j_password': neo4j_password,
+        'publisher.neo4j.neo4j_encrypted': False,
         'publisher.neo4j.job_publish_tag': 'unique_lastupdated_tag',  # should use unique tag here like {ds}
     })
 
@@ -189,6 +192,7 @@ def create_es_publisher_sample_job(elasticsearch_index_alias='table_search_index
         'extractor.search_data.extractor.neo4j.model_class': model_name,
         'extractor.search_data.extractor.neo4j.neo4j_auth_user': neo4j_user,
         'extractor.search_data.extractor.neo4j.neo4j_auth_pw': neo4j_password,
+        'extractor.search_data.extractor.neo4j.neo4j_encrypted': False,
         'loader.filesystem.elasticsearch.file_path': extracted_search_data_path,
         'loader.filesystem.elasticsearch.mode': 'w',
         'publisher.elasticsearch.file_path': extracted_search_data_path,

tests/unit/publisher/test_neo4j_csv_publisher.py

@@ -4,7 +4,7 @@
 import uuid
 
 from mock import patch, MagicMock
-from neo4j.v1 import GraphDatabase
+from neo4j import GraphDatabase
 from pyhocon import ConfigFactory
 
 from databuilder.publisher import neo4j_csv_publisher

tests/unit/task/test_neo4j_staleness_removal_task.py

@@ -6,7 +6,7 @@
 import unittest
 
 from mock import patch
-from neo4j.v1 import GraphDatabase
+from neo4j import GraphDatabase
 from pyhocon import ConfigFactory
 
 from databuilder.publisher import neo4j_csv_publisher