build: add recipe code for new autoroller

scripts/slave/recipe_modules/luci_config/api.py

+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+from recipe_engine import recipe_api
+
+class LuciConfigApi(recipe_api.RecipeApi):
+  def get_projects(self):
+    """Fetch the mapping of project id to url from luci-config.
+
+    Returns:
+      A dictionary mapping project id to its luci-config project spec (among
+      which there is a repo_url key).
+    """
+    cmd = ['curl', 'https://luci-config.appspot.com/_ah/api/config/v1/projects']
+    fetch_result = self.m.step('Get project urls',

[martiniss, 2016/04/07 18:27:59]

Please change this to use the fetch module. See
https://code.google.com/p/chromium/codesearch#chromium/build/scripts/slave/re...
for an example of usage; if you could convert the recipe_roll_tryjob to use
this, that would be nice. I can do it later though.

This allows us to pass in auth tokens without leakage.

[Paweł Hajdan Jr., 2016/04/07 20:32:15]

Would you be OK with a TODO? This is what recipe_roller currently uses, and it's
known to work.
Could you explain more? As far as I can tell, in neither case are we leaking any
auth tokens.

[martiniss, 2016/04/07 21:27:12]

A TODO is fine for now.
Internally we are. See
https://uberchromegw.corp.google.com/i/internal.infra.cron/builders/recipe-ro...
for example; it puts the raw auth token on the command line.

This is fine for here, since we aren't using the auth token.

[Paweł Hajdan Jr., 2016/04/08 08:47:00]

Good point. Added a TODO.

+        cmd,
+        stdout=self.m.json.output(),
+        step_test_data=lambda: self.m.json.test_api.output_stream({
+               'projects': [
+                   {
+                       'repo_type': 'GITILES',
+                       'id': 'recipe_engine',
+                       'repo_url': 'https://repo.repo/recipes-py',
+                   },
+                   {
+                       'repo_type': 'GITILES',
+                       'id': 'build',
+                       'repo_url': 'https://repo.repo/chromium/build',
+                   }
+               ],
+           }))
+    mapping = {}
+    for project in fetch_result.stdout['projects']:
+      mapping[project['id']] = project
+    return mapping