feat(publicip): support custom API url echoip#https://... (#2529)

internal/publicip/api/echoip.go

@@ -0,0 +1,104 @@
+package api
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/netip"
+	"strings"
+
+	"github.com/qdm12/gluetun/internal/models"
+)
+
+type echoip struct {
+	client *http.Client
+	url    string
+}
+
+func newEchoip(client *http.Client, url string) *echoip {
+	return &echoip{
+		client: client,
+		url:    url,
+	}
+}
+
+func (e *echoip) String() string {
+	s := e.url
+	s = strings.TrimPrefix(s, "http://")
+	s = strings.TrimPrefix(s, "https://")
+	return s
+}
+
+func (e *echoip) CanFetchAnyIP() bool {
+	return true
+}
+
+func (e *echoip) Token() string {
+	return ""
+}
+
+// FetchInfo obtains information on the ip address provided
+// using the echoip API at the url given. If the ip is the zero value,
+// the public IP address of the machine is used as the IP.
+func (e *echoip) FetchInfo(ctx context.Context, ip netip.Addr) (
+	result models.PublicIP, err error,
+) {
+	url := e.url + "/json"
+	if ip.IsValid() {
+		url += "?ip=" + ip.String()
+	}
+
+	request, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return result, err
+	}
+
+	response, err := e.client.Do(request)
+	if err != nil {
+		return result, err
+	}
+	defer response.Body.Close()
+
+	switch response.StatusCode {
+	case http.StatusOK:
+	case http.StatusTooManyRequests:
+		return result, fmt.Errorf("%w from %s: %s",
+			ErrTooManyRequests, url, response.Status)
+	default:
+		return result, fmt.Errorf("%w from %s: %s",
+			ErrBadHTTPStatus, url, response.Status)
+	}
+
+	decoder := json.NewDecoder(response.Body)
+	var data struct {
+		IP         netip.Addr `json:"ip,omitempty"`
+		Country    string     `json:"country,omitempty"`
+		RegionName string     `json:"region_name,omitempty"`
+		ZipCode    string     `json:"zip_code,omitempty"`
+		City       string     `json:"city,omitempty"`
+		Latitude   float32    `json:"latitude,omitempty"`
+		Longitude  float32    `json:"longitude,omitempty"`
+		Hostname   string     `json:"hostname,omitempty"`
+		// Timezone in the form America/Montreal
+		Timezone string `json:"time_zone,omitempty"`
+		AsnOrg   string `json:"asn_org,omitempty"`
+	}
+	err = decoder.Decode(&data)
+	if err != nil {
+		return result, fmt.Errorf("decoding response: %w", err)
+	}
+
+	result = models.PublicIP{
+		IP:           data.IP,
+		Region:       data.RegionName,
+		Country:      data.Country,
+		City:         data.City,
+		Hostname:     data.Hostname,
+		Location:     fmt.Sprintf("%f,%f", data.Latitude, data.Longitude),
+		Organization: data.AsnOrg,
+		PostalCode:   data.ZipCode,
+		Timezone:     data.Timezone,
+	}
+	return result, nil
+}