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..29f9b71664ab7f856b49229dedbb5d8b2139d73c 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.
@@ -750,11 +752,12 @@ 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
@@ -861,11 +864,12 @@ 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 +944,38 @@ class RecipeEngine(object):
     """
     return step.as_jsonish()
 
+  def depend_on(self, recipe, properties, distributor=None):
+    return self.depend_on_multi(
+        ((recipe, properties),), distributor=distributor)[0]
+
+  def depend_on_multi(self, dependencies, distributor=None):
+    if self._test_data.enabled:
+      results = []
+      for recipe, properties in dependencies:
+        recipe_script = self._universe.load_recipe(recipe)
+
+        f = lambda *args, **kwargs: self._test_data.depend_on_data[types.freeze(
+            (recipe, properties),)]
+        results.append(loader._invoke_with_properties(
+            f, properties, recipe_script.PROPERTIES, properties.keys()))
+

[Paweł Hajdan Jr., 2015/11/18 16:56:03]

nit: Remove redundant empty line.

[martiniss, 2015/11/18 22:03:29]

Fixed.

+
+      return results
+
+    # TODO(martiniss) Add DM integration
+    # For now, we just run the recipe locally.
+    for recipe, properties in dependencies:
+      with tempfile.NamedTemporaryFile() as f:
+        cmd = [sys.executable, self._universe.package_deps.engine_recipes_py,
+               '--package=%s' % self._universe.config_file, 'run',
+               '--output-result-json=%s' % f.name, recipe]
+        cmd.extend(['%s=%s' % (k, v) for k, v in properties.iteritems()])
+
+        retcode = subprocess.call(cmd)
+        if retcode != 0:
+          raise recipe_api.InfraFailure(

[Paweł Hajdan Jr., 2015/11/18 16:56:03]

This isn't necessarily an infra failure, right? Dependent recipes can fail for
legitimate non-infra reasons. Or is such a failure reported in some other way?
In that case please clarify in a comment.

[martiniss, 2015/11/18 22:03:30]

True. I changed this to be a step failure. 

This recipe could return 1 if the actual recipe failed; compile failed because
the patch was bad, for example. 

+              'depend on %s failed with %d' % (recipe, retcode))
+        return json.load(f)
+
+