Pass env via context rather than api.step kwargs

See https://groups.google.com/a/chromium.org/d/msg/infra-dev/p8Iq9v9Y4k0/w__b1zTWAQAJ
for more context.

BUG=685746

Change-Id: If0bdcbd354b2535de22a7be78dad86e15c9f2cea
Reviewed-on: https://chromium-review.googlesource.com/456217
Commit-Queue: Paweł Hajdan Jr. <phajdan.jr@chromium.org>
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>

infra/config/recipes.cfg

@@ -4,5 +4,5 @@ deps {
   project_id: "recipe_engine"
   url: "https://chromium.googlesource.com/external/github.com/luci/recipes-py.git"
   branch: "master"
-  revision: "d5a670b19aba7fb9a7f6430d39dab1d3414b578a"
+  revision: "57a75df505dfe20cb1aa6b7536231e56267fa2b8"
 }

recipe_modules/bot_update/api.py

@@ -33,15 +33,16 @@ class BotUpdateApi(recipe_api.RecipeApi):
     assert isinstance(cmd, (list, tuple))
     bot_update_path = self.resource('bot_update.py')
     kwargs.setdefault('infra_step', True)
-    kwargs.setdefault('env', {})
-    kwargs['env'].setdefault('PATH', '%(PATH)s')
-    kwargs['env']['PATH'] = self.m.path.pathsep.join([
-        kwargs['env']['PATH'], str(self._module.PACKAGE_REPO_ROOT)])
+    env = self.m.step.get_from_context('env', {})
+    env.setdefault('PATH', '%(PATH)s')
+    env['PATH'] = self.m.path.pathsep.join([
+        env['PATH'], str(self._module.PACKAGE_REPO_ROOT)])
     # These are to prevent git from hanging.  If the git connection is slower
     # than 1KB/s for more than 5 minutes then git will kill the connection
     # and die with an error "error: RPC failed; curl 28 Operation too slow"
-    kwargs['env']['GIT_HTTP_LOW_SPEED_LIMIT'] = 1000
-    kwargs['env']['GIT_HTTP_LOW_SPEED_TIME'] = 300
+    env['GIT_HTTP_LOW_SPEED_LIMIT'] = 1000
+    env['GIT_HTTP_LOW_SPEED_TIME'] = 300
+    with self.m.step.context({'env': env}):
       return self.m.python(name, bot_update_path, cmd, **kwargs)
 
   @property
@@ -54,9 +55,10 @@ class BotUpdateApi(recipe_api.RecipeApi):
                        gerrit_no_rebase_patch_ref=False, **kwargs):
     apply_gerrit_path = self.resource('apply_gerrit.py')
     kwargs.setdefault('infra_step', True)
-    kwargs.setdefault('env', {}).setdefault('PATH', '%(PATH)s')
-    kwargs['env']['PATH'] = self.m.path.pathsep.join([
-        kwargs['env']['PATH'], str(self._module.PACKAGE_REPO_ROOT)])
+    env = self.m.step.get_from_context('env', {})
+    env.setdefault('PATH', '%(PATH)s')
+    env['PATH'] = self.m.path.pathsep.join([
+        env['PATH'], str(self._module.PACKAGE_REPO_ROOT)])
     cmd = [
         '--gerrit_repo', self._repository,
         '--gerrit_ref', self._gerrit_ref or '',
@@ -66,6 +68,7 @@ class BotUpdateApi(recipe_api.RecipeApi):
       cmd.append('--gerrit_no_reset')
     if gerrit_no_rebase_patch_ref:
       cmd.append('--gerrit_no_rebase_patch_ref')
+    with self.m.step.context({'env': env}):
       return self.m.python('apply_gerrit', apply_gerrit_path, cmd, **kwargs)
 
   def ensure_checkout(self, gclient_config=None, suffix=None,

recipe_modules/gclient/api.py

@@ -79,11 +79,13 @@ class GclientApi(recipe_api.RecipeApi):
     if self.spec_alias:
       prefix = ('[spec: %s] ' % self.spec_alias) + prefix
 
-    kwargs.setdefault('env', {})
-    kwargs['env'].setdefault('PATH', '%(PATH)s')
-    kwargs['env']['PATH'] = self.m.path.pathsep.join([
-        kwargs['env']['PATH'], str(self._module.PACKAGE_REPO_ROOT)])
+    # TODO(phajdan.jr): create a helper for adding to PATH.
+    env = self.m.step.get_from_context('env', {})
+    env.setdefault('PATH', '%(PATH)s')
+    env['PATH'] = self.m.path.pathsep.join([
+        env['PATH'], str(self._module.PACKAGE_REPO_ROOT)])
 
+    with self.m.step.context({'env': env}):
       return self.m.python(prefix + name,
                            self.package_repo_resource('gclient.py'),
                            cmd,

recipe_modules/gerrit/__init__.py

@@ -3,4 +3,5 @@ DEPS = [
   'recipe_engine/path',
   'recipe_engine/python',
   'recipe_engine/raw_io',
+  'recipe_engine/step',
 ]

recipe_modules/gerrit/api.py

@@ -12,11 +12,12 @@ class GerritApi(recipe_api.RecipeApi):
     assert isinstance(cmd, (list, tuple))
     prefix = 'gerrit '
 
-    kwargs.setdefault('env', {})
-    kwargs['env'].setdefault('PATH', '%(PATH)s')
-    kwargs['env']['PATH'] = self.m.path.pathsep.join([
-        kwargs['env']['PATH'], str(self._module.PACKAGE_REPO_ROOT)])
+    env = self.m.step.get_from_context('env', {})
+    env.setdefault('PATH', '%(PATH)s')
+    env['PATH'] = self.m.path.pathsep.join([
+        env['PATH'], str(self._module.PACKAGE_REPO_ROOT)])
 
+    with self.m.step.context({'env': env}):
       return self.m.python(prefix + name,
                            self.package_repo_resource('gerrit_client.py'),
                            cmd,

recipe_modules/git/api.py

@@ -278,9 +278,9 @@ class GitApi(recipe_api.RecipeApi):
             name='count-objects before %s' % fetch_step_name,
             step_test_data=lambda: self.m.raw_io.test_api.stream_output(
                 self.test_api.count_objects_output(1000)))
+      with self.m.step.context({'env': fetch_env}):
         self('retry', 'fetch', *fetch_args,
           name=fetch_step_name,
-        env=fetch_env,
           stderr=fetch_stderr,
           can_fail_build=can_fail_build)
       if display_fetch_size:
@@ -413,7 +413,7 @@ class GitApi(recipe_api.RecipeApi):
       upstream (str): to origin/master.
       kwargs: Forwarded to '__call__'.
     """
-    env = kwargs.pop('env', {})
+    env = self.m.step.get_from_context('env', {})
     env['PATH'] = self.m.path.pathsep.join([
         str(self.package_repo_resource()), '%(PATH)s'])
     args = ['new-branch', branch]
@@ -421,4 +421,5 @@ class GitApi(recipe_api.RecipeApi):
       args.extend(['--upstream', upstream])
     if not name:
       name = 'git new-branch %s' % branch
-    return self(*args, name=name, env=env, **kwargs)
+    with self.m.step.context({'env': env}):
+      return self(*args, name=name, **kwargs)

recipe_modules/presubmit/__init__.py

 DEPS = [
   'recipe_engine/path',
   'recipe_engine/python',
+  'recipe_engine/step',
 ]

recipe_modules/presubmit/api.py

@@ -14,10 +14,11 @@ class PresubmitApi(recipe_api.RecipeApi):
 
     name = kwargs.pop('name', 'presubmit')
 
-    kwargs.setdefault('env', {})
-    kwargs['env'].setdefault('PATH', '%(PATH)s')
-    kwargs['env']['PATH'] = self.m.path.pathsep.join([
-        kwargs['env']['PATH'], str(self._module.PACKAGE_REPO_ROOT)])
+    env = self.m.step.get_from_context('env', {})
+    env.setdefault('PATH', '%(PATH)s')
+    env['PATH'] = self.m.path.pathsep.join([
+        env['PATH'], str(self._module.PACKAGE_REPO_ROOT)])
 
+    with self.m.step.context({'env': env}):
       return self.m.python(
           name, self.presubmit_support_path, list(args), **kwargs)