istio.io/istio@v0.0.0-20240520182934-d79c90f27776/pkg/config/visibility/visibility.go (about)

     1  // Copyright Istio Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package visibility
    16  
    17  import (
    18  	"fmt"
    19  
    20  	"istio.io/istio/pkg/config/labels"
    21  )
    22  
    23  // Instance defines whether a given config or service is exported to local namespace, some set of namespaces, or
    24  // all namespaces or none
    25  type Instance string
    26  
    27  const (
    28  	// Private implies namespace local config
    29  	Private Instance = "."
    30  	// Public implies config is visible to all
    31  	Public Instance = "*"
    32  	// None implies service is visible to no one. Used for services only
    33  	None Instance = "~"
    34  )
    35  
    36  // Validate a visibility value ( ./*/~/some namespace name which is DNS1123 label)
    37  func (v Instance) Validate() (errs error) {
    38  	switch v {
    39  	case Private, Public:
    40  		return nil
    41  	case None:
    42  		return fmt.Errorf("exportTo ~ (none) is not allowed for Istio configuration objects")
    43  	default:
    44  		if !labels.IsDNS1123Label(string(v)) {
    45  			return fmt.Errorf("only .,*, or a valid DNS 1123 label is allowed as exportTo entry")
    46  		}
    47  	}
    48  	return nil
    49  }