swarming: refactor cipd input

appengine/swarming/server/config.py

Index: appengine/swarming/server/config.py
diff --git a/appengine/swarming/server/config.py b/appengine/swarming/server/config.py
index 0615f9484db15cad2f114a4cf93e9d0d0e7367b8..8c7f205ca1836def97d8bf1bc9e2ac1b10d15215 100644
--- a/appengine/swarming/server/config.py
+++ b/appengine/swarming/server/config.py
@@ -6,6 +6,7 @@
 
 import logging
 import posixpath
+import re
 
 from components import config
 from components import gitiles
@@ -14,11 +15,12 @@ from components import utils
 from components.config import validation
 
 from proto import config_pb2
-from server import task_request
 
+import cipd
 
 SETTINGS_CFG_FILENAME = 'settings.cfg'
 SECONDS_IN_YEAR = 60 * 60 * 24 * 365
+NAMESPACE_RE = re.compile(r'^[a-z0-9A-Z\-._]+$')
 
 
 ConfigApi = config.ConfigApi
@@ -32,10 +34,26 @@ def validate_isolate_settings(cfg, ctx):
     if not cfg.default_server.startswith(('https://', 'http://')):
       ctx.error('default_server must start with "https://" or "http://"')
 
-    if not task_request.NAMESPACE_RE.match(cfg.default_namespace):
+    if not NAMESPACE_RE.match(cfg.default_namespace):
       ctx.error('invalid namespace "%s"', cfg.default_namespace)
 
 
+def validate_cipd_settings(cfg, ctx=None):
+  """Validates CipdSettings message stored in settings.cfg."""
+  ctx = ctx or validation.Context.raise_on_error()
+  if not cfg.server_host:
+    ctx.error('server_host is not set')
+
+  if not cipd.is_valid_package_name_template(cfg.client_package_name):
+    ctx.error('invalid client_package_name "%s"', cfg.client_package_name)
+  elif cipd.PARAM_PLATFORM not in cfg.client_package_name:
+    ctx.error(
+        'client_package_name does not use %s parameter', cipd.PARAM_PLATFORM)
+
+  if not cipd.is_valid_version(cfg.client_package_version):
+    ctx.error('invalid client_package_version "%s"', cfg.client_package_version)
+
+
 @validation.self_rule(SETTINGS_CFG_FILENAME, config_pb2.SettingsCfg)
 def validate_settings(cfg, ctx):
   """Validates settings.cfg file against proto message schema."""
@@ -54,6 +72,10 @@ def validate_settings(cfg, ctx):
     with ctx.prefix('isolate: '):
       validate_isolate_settings(cfg.isolate, ctx)
 
+  if cfg.HasField('cipd'):
+    with ctx.prefix('cipd: '):
+      validate_cipd_settings(cfg.cipd, ctx)
+
 
 @utils.memcache('config:get_configs_url', time=60)
 def _get_configs_url():