Set global variable overrides on the command line with --vars (#640)

* Set global variable overrides on the command line with --vars

* pep8

* integration tests for cli vars

dbt/main.py

@@ -295,6 +295,16 @@ def parse_args(args):
         help='Which target to load for the given profile'
     )
 
+    base_subparser.add_argument(
+        '--vars',
+        type=str,
+        default='{}',
+        help="""
+            Supply variables to the project. This argument overrides
+            variables defined in your dbt_project.yml file. This argument
+            should be a YAML string, eg. '{my_variable: my_value}'"""
+    )
+
     sub = subs.add_parser('init', parents=[base_subparser])
     sub.add_argument('project_name', type=str, help='Name of the new project')
     sub.set_defaults(cls=init_task.InitTask, which='init')

dbt/project.py

@@ -87,6 +87,12 @@ def __init__(self, cfg, profiles, profiles_dir, profile_to_load=None,
                 "Could not find profile named '{}'"
                 .format(self.profile_to_load), self)
 
+        global_vars = dbt.utils.parse_cli_vars(getattr(args, 'vars', '{}'))
+        if 'vars' not in self.cfg['models']:
+            self.cfg['models']['vars'] = {}
+
+        self.cfg['models']['vars'].update(global_vars)
+
     def __str__(self):
         return pprint.pformat({'project': self.cfg, 'profiles': self.profiles})
 

dbt/utils.py

@@ -9,6 +9,7 @@
 from dbt.compat import basestring
 from dbt.logger import GLOBAL_LOGGER as logger
 from dbt.node_types import NodeType
+from dbt.clients import yaml_helper
 
 
 DBTConfigKeys = [
@@ -375,3 +376,20 @@ def invalid_ref_fail_unless_test(node, target_model_name,
             node,
             target_model_name,
             target_model_package)
+
+
+def parse_cli_vars(var_string):
+    try:
+        cli_vars = yaml_helper.load_yaml_text(var_string)
+        var_type = type(cli_vars)
+        if var_type == dict:
+            return cli_vars
+        else:
+            type_name = var_type.__name__
+            dbt.exceptions.raise_compiler_error(
+                "The --vars argument must be a YAML dictionary, but was "
+                "of type '{}'".format(type_name))
+    except dbt.exceptions.ValidationException as e:
+        logger.error(
+                "The YAML provided in the --vars argument is not valid.\n")
+        raise

test/integration/028_cli_vars/models_complex/complex_model.sql

@@ -0,0 +1,6 @@
+
+select
+    '{{ var("variable_1") }}'::varchar as var_1,
+    '{{ var("variable_2")[0] }}'::varchar as var_2,
+    '{{ var("variable_3")["value"] }}'::varchar as var_3
+

test/integration/028_cli_vars/models_complex/schema.yml

@@ -0,0 +1,7 @@
+
+complex_model:
+    constraints:
+        accepted_values:
+            - {field: var_1, values: ["abc"]}
+            - {field: var_2, values: ["def"]}
+            - {field: var_3, values: ["jkl"]}

test/integration/028_cli_vars/models_simple/schema.yml

@@ -0,0 +1,5 @@
+
+simple_model:
+    constraints:
+        accepted_values:
+            - {field: simple, values: ["abc"]}

test/integration/028_cli_vars/models_simple/simple_model.sql

@@ -0,0 +1,4 @@
+
+select
+    '{{ var("simple") }}'::varchar as simple
+

test/integration/028_cli_vars/test_cli_vars.py

@@ -0,0 +1,54 @@
+from nose.plugins.attrib import attr
+from test.integration.base import DBTIntegrationTest
+import yaml
+
+
+class TestCLIVars(DBTIntegrationTest):
+    @property
+    def schema(self):
+        return "cli_vars_028"
+
+    @property
+    def models(self):
+        return "test/integration/028_cli_vars/models_complex"
+
+    @attr(type='postgres')
+    def test__cli_vars_longform(self):
+        self.use_default_project()
+        self.use_profile('postgres')
+
+        cli_vars = {
+            "variable_1": "abc",
+            "variable_2": ["def", "ghi"],
+            "variable_3": {
+                "value": "jkl"
+            }
+        }
+        self.run_dbt(["run", "--vars", yaml.dump(cli_vars)])
+        self.run_dbt(["test"])
+
+
+class TestCLIVarsSimple(DBTIntegrationTest):
+    @property
+    def schema(self):
+        return "cli_vars_028"
+
+    @property
+    def models(self):
+        return "test/integration/028_cli_vars/models_simple"
+
+    @attr(type='postgres')
+    def test__cli_vars_shorthand(self):
+        self.use_default_project()
+        self.use_profile('postgres')
+
+        self.run_dbt(["run", "--vars", "simple: abc"])
+        self.run_dbt(["test"])
+
+    @attr(type='postgres')
+    def test__cli_vars_longer(self):
+        self.use_default_project()
+        self.use_profile('postgres')
+
+        self.run_dbt(["run", "--vars", "{simple: abc, unused: def}"])
+        self.run_dbt(["test"])