util/structfs: import https://github.com/unistack-org/go-structfs

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

util/structfs/metadata_digitalocean.go

@@ -0,0 +1,67 @@
+package structfs
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+	"time"
+)
+
+type DigitalOceanMetadata struct {
+	Metadata struct {
+		V1 struct {
+			DropletID  int64    `json:"droplet_id"`
+			Hostname   string   `json:"hostname"`
+			VendorData string   `json:"vendor_data"`
+			PublicKeys []string `json:"public_keys"`
+			Region     string   `json:"region"`
+			Interfaces struct {
+				Private []struct {
+					IPv4 struct {
+						Address string `json:"ip_address"`
+						Netmask string `json:"netmask"`
+						Gateway string `json:"gateway"`
+					}
+					Mac  string `json:"mac"`
+					Type string `json:"type"`
+				} `json:"private"`
+				Public []struct {
+					IPv4 struct {
+						Address string `json:"ip_address"`
+						Netmask string `json:"netmask"`
+						Gateway string `json:"gateway"`
+					} `json:"ipv4"`
+					IPv6 struct {
+						Address string `json:"ip_address"`
+						CIDR    int    `json:"cidr"`
+						Gateway string `json:"gateway"`
+					} `json:"ipv6"`
+					Mac  string `json:"mac"`
+					Type string `json:"type"`
+				} `json:"public"`
+			} `json:"interfaces"`
+			FloatingIP struct {
+				IPv4 struct {
+					Active bool `json:"active"`
+				} `json:"ipv4"`
+			} `json:"floating_ip"`
+			DNS struct {
+				Nameservers []string `json:"nameservers"`
+			} `json:"dns"`
+			Features map[string]interface{} `json:"features"`
+		} `json:"v1"`
+	} `json:"metadata"`
+}
+
+func (stfs *DigitalOceanMetadata) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	switch r.URL.Path {
+	case "/metadata/v1.json":
+		json.NewEncoder(w).Encode(stfs.Metadata.V1)
+	default:
+		fs := FileServer(stfs, "json", time.Now())
+		idx := strings.Index(r.URL.Path[1:], "/")
+		r.URL.Path = strings.Replace(r.URL.Path[idx+1:], "/metadata/v1/", "", 1)
+		r.RequestURI = r.URL.Path
+		fs.ServeHTTP(w, r)
+	}
+}