VictoriaMetrics/lib/promscrape/discovery/kubernetes/service.go

114 lines
3.2 KiB
Go

package kubernetes
import (
"encoding/json"
"fmt"
)
// getServicesLabels returns labels for k8s services obtained from the given cfg.
func getServicesLabels(cfg *APIConfig) ([]map[string]string, error) {
svcs, err := getServices(cfg)
if err != nil {
return nil, err
}
var ms []map[string]string
for _, svc := range svcs {
ms = svc.appendTargetLabels(ms)
}
return ms, nil
}
func getServices(cfg *APIConfig) ([]Service, error) {
data, err := getAPIResponse(cfg, "service", "/api/v1/services")
if err != nil {
return nil, fmt.Errorf("cannot obtain services data from API server: %s", err)
}
sl, err := parseServiceList(data)
if err != nil {
return nil, fmt.Errorf("cannot parse services response from API server: %s", err)
}
return sl.Items, nil
}
// ServiceList is k8s service list.
//
// See https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.17/#servicelist-v1-core
type ServiceList struct {
Items []Service
}
// Service is k8s service.
//
// See https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.17/#service-v1-core
type Service struct {
Metadata ObjectMeta
Spec ServiceSpec
}
// ServiceSpec is k8s service spec.
//
// See https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.17/#servicespec-v1-core
type ServiceSpec struct {
ClusterIP string
ExternalName string
Type string
Ports []ServicePort
}
// ServicePort is k8s service port.
//
// See https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.17/#serviceport-v1-core
type ServicePort struct {
Name string
Protocol string
Port int
}
// parseServiceList parses ServiceList from data.
func parseServiceList(data []byte) (*ServiceList, error) {
var sl ServiceList
if err := json.Unmarshal(data, &sl); err != nil {
return nil, fmt.Errorf("cannot unmarshal ServiceList from %q: %s", data, err)
}
return &sl, nil
}
// appendTargetLabels appends labels for each port of the given Service s to ms and returns the result.
//
// See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#service
func (s *Service) appendTargetLabels(ms []map[string]string) []map[string]string {
host := fmt.Sprintf("%s.%s.svc", s.Metadata.Name, s.Metadata.Namespace)
for _, sp := range s.Spec.Ports {
addr := joinHostPort(host, sp.Port)
m := map[string]string{
"__address__": addr,
"__meta_kubernetes_service_port_name": sp.Name,
"__meta_kubernetes_service_port_protocol": sp.Protocol,
}
s.appendCommonLabels(m)
ms = append(ms, m)
}
return ms
}
func (s *Service) appendCommonLabels(m map[string]string) {
m["__meta_kubernetes_namespace"] = s.Metadata.Namespace
m["__meta_kubernetes_service_name"] = s.Metadata.Name
m["__meta_kubernetes_service_type"] = s.Spec.Type
if s.Spec.Type != "ExternalName" {
m["__meta_kubernetes_service_cluster_ip"] = s.Spec.ClusterIP
} else {
m["__meta_kubernetes_service_external_name"] = s.Spec.ExternalName
}
s.Metadata.registerLabelsAndAnnotations("__meta_kubernetes_service", m)
}
func getService(svcs []Service, namespace, name string) *Service {
for i := range svcs {
svc := &svcs[i]
if svc.Metadata.Name == name && svc.Metadata.Namespace == namespace {
return svc
}
}
return nil
}