show helpful messages if permissions denied in db

dbt/runner.py

@@ -10,6 +10,17 @@
 from dbt.source import Source
 from dbt.utils import find_model_by_name
 
+SCHEMA_PERMISSION_DENIED_MESSAGE = """The user '{user}' does not have sufficient permissions to create the schema '{schema}'.
+Either create the schema  manually, or adjust the permissions of the '{user}' user."""
+
+RELATION_PERMISSION_DENIED_MESSAGE = """The user '{user}' does not have sufficient permissions to create the model '{model}' \
+in the schema '{schema}'.\nPlease adjust the permissions of the '{user}' user on the '{schema}' schema.
+With a superuser account, execute the following commands, then re-run dbt.
+
+grant usage, create on schema "{schema}" to "{user}";
+grant select on all tables in schema "{schema}" to "{user}";
+"""
+
 class Runner:
     def __init__(self, project, target_path, run_mode):
         self.project = project
@@ -32,12 +43,34 @@ def deserialize_graph(self):
 
         return linker
 
-    def create_schema(self):
-        target_cfg = self.project.run_environment()
+    def create_schema(self, schema_name):
+        target = self.get_target()
+        with target.get_handle() as handle:
+            with handle.cursor() as cursor:
+                cursor.execute('create schema if not exists "{}"'.format(schema_name))
+
+    def get_schemas(self):
         target = self.get_target()
+        existing = []
         with target.get_handle() as handle:
             with handle.cursor() as cursor:
-                cursor.execute('create schema if not exists "{}"'.format(target_cfg['schema']))
+                cursor.execute('select nspname from pg_catalog.pg_namespace')
+
+                existing = [name for (name,) in cursor.fetchall()]
+        return existing
+
+    def create_schema_or_exit(self, schema_name):
+
+        target_cfg = self.project.run_environment()
+        user = target_cfg['user']
+
+        try:
+            self.create_schema(schema_name)
+        except psycopg2.ProgrammingError as e:
+            if "permission denied for" in e.diag.message_primary:
+                raise RuntimeError(SCHEMA_PERMISSION_DENIED_MESSAGE.format(schema=schema_name, user=user))
+            else:
+                raise e
 
     def query_for_existing(self, cursor, schema):
         sql = """
@@ -98,7 +131,13 @@ def execute_models(self, linker, models, limit_to=None):
                         handle.commit()
 
                     print("Running {} of {} -- Creating relation {}.{}".format(index + 1, num_models, target.schema, model.name))
-                    self.__do_execute(cursor, model.contents, model)
+                    try:
+                        self.__do_execute(cursor, model.contents, model)
+                    except psycopg2.ProgrammingError as e:
+                        if "permission denied for" in e.diag.message_primary:
+                            raise RuntimeError(RELATION_PERMISSION_DENIED_MESSAGE.format(model=model.name, schema=target.schema, user=target.user))
+                        else:
+                            raise e
                     handle.commit()
                     yield model
 
@@ -117,8 +156,16 @@ def run(self, specified_models=None):
                     print("ERROR: {}".format(str(e)))
                     print("Exiting")
                     return
+
+        target_cfg = self.project.run_environment()
+        schema_name = target_cfg['schema']
+
         try:
-            self.create_schema()
+            schemas = self.get_schemas()
+
+            if schema_name not in schemas:
+                self.create_schema_or_exit(schema_name)
+
             for model in self.execute_models(linker, compiled_models, limit_to):
                 yield model, True
         except psycopg2.OperationalError as e: