Matthias Andreas Benkard | 832a54e | 2019-01-29 09:27:38 +0100 | [diff] [blame^] | 1 | /* |
| 2 | Copyright 2014 The Kubernetes Authors. |
| 3 | |
| 4 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | you may not use this file except in compliance with the License. |
| 6 | You may obtain a copy of the License at |
| 7 | |
| 8 | http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | |
| 10 | Unless required by applicable law or agreed to in writing, software |
| 11 | distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | See the License for the specific language governing permissions and |
| 14 | limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package names |
| 18 | |
| 19 | import ( |
| 20 | "fmt" |
| 21 | |
| 22 | utilrand "k8s.io/apimachinery/pkg/util/rand" |
| 23 | ) |
| 24 | |
| 25 | // NameGenerator generates names for objects. Some backends may have more information |
| 26 | // available to guide selection of new names and this interface hides those details. |
| 27 | type NameGenerator interface { |
| 28 | // GenerateName generates a valid name from the base name, adding a random suffix to the |
| 29 | // the base. If base is valid, the returned name must also be valid. The generator is |
| 30 | // responsible for knowing the maximum valid name length. |
| 31 | GenerateName(base string) string |
| 32 | } |
| 33 | |
| 34 | // simpleNameGenerator generates random names. |
| 35 | type simpleNameGenerator struct{} |
| 36 | |
| 37 | // SimpleNameGenerator is a generator that returns the name plus a random suffix of five alphanumerics |
| 38 | // when a name is requested. The string is guaranteed to not exceed the length of a standard Kubernetes |
| 39 | // name (63 characters) |
| 40 | var SimpleNameGenerator NameGenerator = simpleNameGenerator{} |
| 41 | |
| 42 | const ( |
| 43 | // TODO: make this flexible for non-core resources with alternate naming rules. |
| 44 | maxNameLength = 63 |
| 45 | randomLength = 5 |
| 46 | maxGeneratedNameLength = maxNameLength - randomLength |
| 47 | ) |
| 48 | |
| 49 | func (simpleNameGenerator) GenerateName(base string) string { |
| 50 | if len(base) > maxGeneratedNameLength { |
| 51 | base = base[:maxGeneratedNameLength] |
| 52 | } |
| 53 | return fmt.Sprintf("%s%s", base, utilrand.String(randomLength)) |
| 54 | } |