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| 1 | +package main |
| 2 | + |
| 3 | +// #include <stdio.h> |
| 4 | +// #include <stdlib.h> |
| 5 | +import "C" |
| 6 | + |
| 7 | +import ( |
| 8 | + "context" |
| 9 | + "encoding/json" |
| 10 | + "log" |
| 11 | + "strings" |
| 12 | + "unicode" |
| 13 | + "unsafe" |
| 14 | + |
| 15 | + "github.com/ericchiang/k8s" |
| 16 | + corev1 "github.com/ericchiang/k8s/apis/core/v1" |
| 17 | +) |
| 18 | + |
| 19 | +type endpoints struct { |
| 20 | + IPs []string `json:"ips"` |
| 21 | +} |
| 22 | + |
| 23 | +// GetEndpoints searches the endpoints of a service returning a list of IP addresses. |
| 24 | +//export GetEndpoints |
| 25 | +func GetEndpoints(namespace, service, defSeeds *C.char) *C.char { |
| 26 | + ns := C.GoString(namespace) |
| 27 | + svc := C.GoString(service) |
| 28 | + seeds := C.GoString(defSeeds) |
| 29 | + |
| 30 | + s := strings.Map(func(r rune) rune { |
| 31 | + if unicode.IsSpace(r) { |
| 32 | + return -1 |
| 33 | + } |
| 34 | + return r |
| 35 | + }, seeds) |
| 36 | + |
| 37 | + nseeds := strings.Split(s, ",") |
| 38 | + client, err := k8s.NewInClusterClient() |
| 39 | + if err != nil { |
| 40 | + log.Printf("unexpected error opening a connection against API server: %v\n", err) |
| 41 | + log.Printf("returning default seeds: %v\n", nseeds) |
| 42 | + return buildEndpoints(nseeds) |
| 43 | + } |
| 44 | + |
| 45 | + ips := make([]string, 0) |
| 46 | + |
| 47 | + var endpoints corev1.Endpoints |
| 48 | + err = client.Get(context.Background(), ns, svc, &endpoints) |
| 49 | + if err != nil { |
| 50 | + log.Printf("unexpected error obtaining information about service endpoints: %v\n", err) |
| 51 | + log.Printf("returning default seeds: %v\n", nseeds) |
| 52 | + return buildEndpoints(nseeds) |
| 53 | + } |
| 54 | + |
| 55 | + for _, endpoint := range endpoints.Subsets { |
| 56 | + for _, address := range endpoint.Addresses { |
| 57 | + ips = append(ips, *address.Ip) |
| 58 | + } |
| 59 | + } |
| 60 | + |
| 61 | + if len(ips) == 0 { |
| 62 | + return buildEndpoints(nseeds) |
| 63 | + } |
| 64 | + |
| 65 | + return buildEndpoints(ips) |
| 66 | +} |
| 67 | + |
| 68 | +func buildEndpoints(ips []string) *C.char { |
| 69 | + b, err := json.Marshal(&endpoints{ips}) |
| 70 | + if err != nil { |
| 71 | + log.Printf("unexpected error serializing JSON response: %v\n", err) |
| 72 | + rc := C.CString(`{"ips":[]}`) |
| 73 | + defer C.free(unsafe.Pointer(rc)) |
| 74 | + return rc |
| 75 | + } |
| 76 | + |
| 77 | + rc := C.CString(string(b)) |
| 78 | + defer C.free(unsafe.Pointer(rc)) |
| 79 | + return rc |
| 80 | +} |
| 81 | + |
| 82 | +func main() {} |
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