prometheus: Make relabeling fields optional

Documentation/api.md

@@ -245,12 +245,12 @@ RelabelConfig allows dynamic rewriting of the label set, being applied to sample
 
 | Field | Description | Scheme | Required |
 | ----- | ----------- | ------ | -------- |
-| sourceLabels | The source labels select values from existing labels. Their content is concatenated using the configured separator and matched against the configured regular expression for the replace, keep, and drop actions. | []string | true |
+| sourceLabels | The source labels select values from existing labels. Their content is concatenated using the configured separator and matched against the configured regular expression for the replace, keep, and drop actions. | []string | false |
 | separator | Separator placed between concatenated source label values. default is ';'. | string | false |
 | targetLabel | Label to which the resulting value is written in a replace action. It is mandatory for replace actions. Regex capture groups are available. | string | false |
 | regex | Regular expression against which the extracted value is matched. defailt is '(.*)' | string | false |
 | modulus | Modulus to take of the hash of the source label values. | uint64 | false |
-| replacement | Replacement value against which a regex replace is performed if the regular expression matches. Regex capture groups are available. Default is '$1' | string | true |
+| replacement | Replacement value against which a regex replace is performed if the regular expression matches. Regex capture groups are available. Default is '$1' | string | false |
 | action | Action to perform based on regex matching. Default is 'replace' | string | false |
 
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example/prometheus-operator-crd/prometheus.crd.yaml

@@ -1832,9 +1832,6 @@ spec:
                             in a replace action. It is mandatory for replace actions.
                             Regex capture groups are available.
                           type: string
-                      required:
-                      - sourceLabels
-                      - replacement
                     type: array
                 required:
                 - url

example/prometheus-operator-crd/servicemonitor.crd.yaml

@@ -123,9 +123,6 @@ spec:
                             in a replace action. It is mandatory for replace actions.
                             Regex capture groups are available.
                           type: string
-                      required:
-                      - sourceLabels
-                      - replacement
                     type: array
                   params:
                     description: Optional HTTP URL parameters

pkg/client/monitoring/v1/openapi_generated.go

@@ -1010,7 +1010,6 @@ func GetOpenAPIDefinitions(ref common.ReferenceCallback) map[string]common.OpenA
 							},
 						},
 					},
-					Required: []string{"sourceLabels", "replacement"},
 				},
 			},
 			Dependencies: []string{},

pkg/client/monitoring/v1/types.go

@@ -238,7 +238,7 @@ type RelabelConfig struct {
 	//The source labels select values from existing labels. Their content is concatenated
 	//using the configured separator and matched against the configured regular expression
 	//for the replace, keep, and drop actions.
-	SourceLabels []string `json:"sourceLabels"`
+	SourceLabels []string `json:"sourceLabels,omitempty"`
 	//Separator placed between concatenated source label values. default is ';'.
 	Separator string `json:"separator,omitempty"`
 	//Label to which the resulting value is written in a replace action.
@@ -250,7 +250,7 @@ type RelabelConfig struct {
 	Modulus uint64 `json:"modulus,omitempty"`
 	//Replacement value against which a regex replace is performed if the
 	//regular expression matches. Regex capture groups are available. Default is '$1'
-	Replacement string `json:"replacement"`
+	Replacement string `json:"replacement,omitempty"`
 	// Action to perform based on regex matching. Default is 'replace'
 	Action string `json:"action,omitempty"`
 }