Add dockerfiles validation

The validation takes 2 steps:
a) render Dockerfile.j2's;
b) verify that all images have parents except ones that are listed in
   base_images config parameter.

This validation ignores list of components because we have repos without
services (debian-base, openstack-base).

Change-Id: I0fd9fb0382b860f04e12993e350c7c23fbcdfda7

fuel_ccp/config/images.py

@@ -4,6 +4,7 @@ DEFAULTS = {
         'tag': 'latest',
         'base_distro': 'debian',
         'base_tag': 'jessie',
+        'base_images': ['base'],
         'maintainer': 'MOS Microservices <mos-microservices@mirantis.com>',
         'image_specs': {},
     },
@@ -18,6 +19,7 @@ SCHEMA = {
             'tag': {'type': 'string'},
             'base_distro': {'type': 'string'},
             'base_tag': {'type': 'string'},
+            'base_images': {'type': 'array', 'items': {'type': 'string'}},
             'maintainer': {'type': 'string'},
             'image_specs': {
                 'type': 'object',

fuel_ccp/validate.py

@@ -1,17 +1,20 @@
 from fuel_ccp.common import utils
 
+from fuel_ccp.validation import dockerfiles
 from fuel_ccp.validation import service as service_validation
 
 
 def validate(components, types):
     if not types:
-        types = ["service-def"]
+        types = ["service-def", "dockerfiles"]
 
     for validation_type in set(types):
         if validation_type == "service-def":
             component_map = utils.get_deploy_components_info()
             service_validation.validate_service_definitions(component_map,
                                                             components)
+        elif validation_type == "dockerfiles":
+            dockerfiles.validate()
         else:
             raise RuntimeError(
                 "Unexpected validation type: '{}'".format(validation_type)

fuel_ccp/validation/dockerfiles.py

@@ -0,0 +1,30 @@
+import logging
+
+from fuel_ccp import build
+from fuel_ccp import config
+
+LOG = logging.getLogger(__name__)
+
+
+def validate():
+    # We ensure that all images' parents are in our repos here
+    dockerfiles = build.get_dockerfiles_tree()
+    LOG.info("Dockerfile tree has been built successfully, no template issues"
+             " or bad image_spec's")
+    # Now we ensure that no unexpected orphat (base) images are found
+    # (i.e. images with malformed FROM line)
+    base_images = config.CONF.images.base_images
+    for dockerfile in dockerfiles.values():
+        name = dockerfile['name']
+        parent = dockerfile['parent']
+        should_have_parent = name not in base_images
+        has_parent = parent is not None
+        if has_parent and not should_have_parent:
+            raise RuntimeError(
+                'Image {} is listed as base image but has a parent {}'.format(
+                    name, parent))
+        if not has_parent and should_have_parent:
+            raise RuntimeError(
+                'Image {} doesn\'t have a parent and is not listed as base'
+                ' image. Malformed FROM line?'.format(name, parent))
+    LOG.info("All Dockerfiles have been verified successfully")