Ensure boostrap_host_exec runs as root

This is necessary for accessing the bind mounted hieradata in the
container in order to determine if the node is the primary node.

With the new validation added to yaml-validate.py, we could spot
potential issues in sahara-api and keystone bootstrap tasks.

The keystone one is a false positive, as the image defaults to the root
user in order to be able to run apache. Still, it is better to be
consistent here and specify the root user nonetheless.

Change-Id: Ib0ff9748d5406f507261e506c19b96750b10e846
Closes-Bug: #1697917

docker/services/keystone.yaml

@@ -113,6 +113,7 @@ outputs:
           keystone_db_sync:
             image: *keystone_image
             net: host
+            user: root
             privileged: false
             detach: false
             volumes: &keystone_volumes
@@ -152,6 +153,7 @@ outputs:
           keystone_bootstrap:
             start_order: 3
             action: exec
+            user: root
             command:
               [ 'keystone', '/usr/bin/bootstrap_host_exec', 'keystone' ,'keystone-manage', 'bootstrap', '--bootstrap-password', {get_param: AdminPassword} ]
       docker_puppet_tasks:

docker/services/sahara-api.yaml

@@ -92,6 +92,7 @@ outputs:
             net: host
             privileged: false
             detach: false
+            user: root
             volumes: &sahara_volumes
               list_concat:
                 - {get_attr: [ContainersCommon, volumes]}

tools/yaml-validate.py

@@ -200,6 +200,23 @@ def validate_docker_service(filename, tpl):
                       % (expected_config_image_parameter, config_volume))
                 return 1
 
+        if 'docker_config' in role_data:
+            docker_config = role_data['docker_config']
+            for _, step in docker_config.items():
+                for _, container in step.items():
+                    if not isinstance(container, dict):
+                        # NOTE(mandre) this skips everything that is not a dict
+                        # so we may ignore some containers definitions if they
+                        # are in a map_merge for example
+                        continue
+                    command = container.get('command', '')
+                    if isinstance(command, list):
+                        command = ' '.join(map(str, command))
+                    if 'bootstrap_host_exec' in command \
+                            and container.get('user') != 'root':
+                      print('ERROR: bootstrap_host_exec needs to run as the root user.')
+                      return 1
+
     if 'parameters' in tpl:
         for param in required_params:
             if param not in tpl['parameters']: