Add simple depends_on API.

recipe_engine/run.py

Index: recipe_engine/run.py
diff --git a/recipe_engine/run.py b/recipe_engine/run.py
index 6949ee70212269c415831ca60fb64b10cbd630e9..b17e3d4c106858538600415055cef3c33120d060 100644
--- a/recipe_engine/run.py
+++ b/recipe_engine/run.py
@@ -72,6 +72,7 @@ import os
 import re
 import subprocess
 import sys
+import tempfile
 import threading
 import traceback
 
@@ -81,6 +82,7 @@ import cStringIO
 from . import loader
 from . import recipe_api
 from . import recipe_test_api
+from . import types
 from . import util
 
 
@@ -433,7 +435,7 @@ def run_steps(properties,
     'TESTING_SLAVENAME' in os.environ)):
     properties['use_mirror'] = False
 
-  engine = RecipeEngine(stream, properties, test_data)
+  engine = RecipeEngine(stream, properties, test_data, universe)
 
   # Create all API modules and top level RunSteps function.  It doesn't launch
   # any recipe code yet; RunSteps needs to be called.
@@ -750,16 +752,21 @@ class RecipeEngine(object):
     * step - uses engine.create_step(...).
 
   """
-  def __init__(self, stream, properties, test_data):
+  def __init__(self, stream, properties, test_data, universe):
     self._stream = stream
     self._properties = properties
     self._test_data = test_data
     self._step_history = collections.OrderedDict()
+    self._universe = universe
 
     self._previous_step_annotation = None
     self._previous_step_result = None
     self._api = None
 
+  def clone(self, stream=None, properties=None, universe=None):
+    return RecipeEngine(stream or self._stream, properties or self._properties,
+                        self._test_data, universe or self._universe)

[luqui, 2015/11/16 20:48:00]

Hmm, isn't test_data mutable, in order for example for the 'unconsumed test
data' check?

[martiniss, 2015/11/18 01:00:00]

Deleted this method. Not needed anymore.

+
   @property
   def properties(self):
     return self._properties
@@ -861,11 +868,12 @@ class RecipeEngine(object):
 
       raise exc(step['name'], step_result)
 
-
   def run(self, recipe_script, api):
     """Run a recipe represented by a recipe_script object.
 
     This function blocks until recipe finishes.
+    It mainly executes the recipe, and has some exception handling logic, and
+    adds the step history to the result.
 
     Args:
       recipe_script: The recipe to run, as represented by a RecipeScript object.
@@ -940,4 +948,34 @@ class RecipeEngine(object):
     """
     return step.as_jsonish()
 
+  def depend_on(self, recipe, properties, distributor=None):
+    return self.depend_on_multi(
+        ((recipe, properties),), distributor=distributor)
+
+  def depend_on_multi(self, dependencies, distributor=None):
+    if self._test_data.enabled:
+      # TODO(martiniss) test properties against the recipe
+      for recipe, properties in dependencies:
+        recipe_script = self._universe.load_recipe(recipe)

[luqui, 2015/11/16 20:48:00]

This precludes one use case, which is that the recipe we depend on was checked
out by a previous step in the recipe, which will requite a more lenient test
mechanism.  This is well designed though, so we can cross that bridge when we
come to it.

+        loader._invoke_with_properties(
+            lambda *args, **kwargs: None, properties, recipe_script.PROPERTIES,
+            properties.keys())
+
+        return self._test_data.depend_on_data[types.freeze((recipe, properties),)]

[luqui, 2015/11/16 20:48:00]

line wrap

+
+    # TODO(martiniss) Add DM integration
+    for recipe, properties in dependencies:
+      recipes_py_loc = os.path.join(
+          self._universe.package_deps._context.repo_root, 'recipes.py')
+
+      with tempfile.NamedTemporaryFile() as f:
+        cmd = [sys.executable, recipes_py_loc,
+               '--package=%s' % self._universe._config_file, 'run',
+               '--result-file=%s' % f.name, recipe]

[luqui, 2015/11/16 20:48:00]

The convention for this argument has been --output-json AFAICT.   I did like
"result" there, though.  Maybe --output-result-json

[martiniss, 2015/11/18 01:00:00]

Fixed.

+        cmd.extend(['%s=%s' % (k, v) for k, v in properties.iteritems()])
+
+        rval = subprocess.call(cmd)

[estaab, 2015/11/17 23:07:16]

We should probably throw an exception when rval isn't 0 since we control the
process running the recipe and should always expect it to be 0, right?

[martiniss, 2015/11/18 01:00:00]

Good idea. Raising an InfraFailure.

+        return json.load(f)
+
+