gcp_spanner_location_v1.yaml

# Copyright 2019 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
 
# This template is for policies restricting the locations of
# Spanner instances in GCP. You can specify a list of regions in the
# "locations" parameter. An instance in the wrong region will raise a violation.
 
apiVersion: templates.gatekeeper.sh/v1alpha1
kind: ConstraintTemplate
metadata:
  name: gcp-spanner-location-v1
spec:
  crd:
    spec:
      names:
        kind: GCPSpannerLocationConstraintV1
      validation:
        openAPIV3Schema:
          properties:
            locations:
              type: array
              items:
                type: string
              description: "List of GCP regions (or region patterns) for
              Spanner instance locations (i.e 'asia*', 'nam3', etc.)."
  targets:
    validation.gcp.forsetisecurity.org:
      rego: | #INLINE("validator/spanner_location.rego")
        #
        # Copyright 2019 Google LLC
        #
        # Licensed under the Apache License, Version 2.0 (the "License");
        # you may not use this file except in compliance with the License.
        # You may obtain a copy of the License at
        #
        #      http://www.apache.org/licenses/LICENSE-2.0
        #
        # Unless required by applicable law or agreed to in writing, software
        # distributed under the License is distributed on an "AS IS" BASIS,
        # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
        # See the License for the specific language governing permissions and
        # limitations under the License.
        #
        
        package templates.gcp.GCPSpannerLocationConstraintV1
        
        import data.validator.gcp.lib as lib
        
        deny[{
        	"msg": message,
        	"details": metadata,
        }] {
        	constraint := input.constraint
        	lib.get_constraint_params(constraint, params)
        
        	asset := input.asset
        
        	# Applies to spanner instances only
        	asset.asset_type == "spanner.googleapis.com/Instance"
        
        	# Retrieve the list of allowed locations
        	locations := params.locations
        
        	# The asset raises a violation if location_is_valid is evaluated to false
        	not location_is_valid(asset, locations)
        
        	message := sprintf("%v is in violation.", [asset.name])
        	metadata := {
        		"resource": asset.name,
        		"valid-locations": locations,
        	}
        }
        
        ###########################
        # Rule Utilities
        ###########################
        
        location_is_valid(asset, locations) {
        	# ensure we have a data object
        	resource := asset.resource.data
        
        	# Retrieve the location 
        	instance_config_parts := split(resource.config, "/")
        	resouce_location := instance_config_parts[3]
        
        	# iterate through the locations
        	location := locations[_]
        
        	# the resource location is valid if it matches one of the passed locations
        	re_match(location, resouce_location)
        }
        #ENDINLINE