chore(publicip): internal/publicip/ipinfo package

internal/publicip/ipinfo/fetch.go

@@ -0,0 +1,74 @@
+package ipinfo
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net"
+	"net/http"
+	"strings"
+
+	"github.com/qdm12/gluetun/internal/constants"
+)
+
+type Fetch struct {
+	client *http.Client
+}
+
+func New(client *http.Client) *Fetch {
+	return &Fetch{
+		client: client,
+	}
+}
+
+var (
+	ErrTooManyRequests = errors.New("too many requests sent for this month")
+	ErrBadHTTPStatus   = errors.New("bad HTTP status received")
+)
+
+// FetchInfo obtains information on the ip address provided
+// using the ipinfo.io API. If the ip is nil, the public IP address
+// of the machine is used as the IP.
+func (f *Fetch) FetchInfo(ctx context.Context, ip net.IP) (
+	result Response, err error) {
+	const baseURL = "https://ipinfo.io/"
+	url := baseURL
+	if ip != nil {
+		url += ip.String()
+	}
+
+	request, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return result, err
+	}
+
+	response, err := f.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: %d %s",
+			ErrTooManyRequests, url, response.StatusCode, response.Status)
+	default:
+		return result, fmt.Errorf("%w from %s: %d %s",
+			ErrBadHTTPStatus, url, response.StatusCode, response.Status)
+	}
+
+	decoder := json.NewDecoder(response.Body)
+	if err := decoder.Decode(&result); err != nil {
+		return result, fmt.Errorf("cannot decode response: %w", err)
+	}
+
+	countryCode := strings.ToLower(result.Country)
+	country, ok := constants.CountryCodes()[countryCode]
+	if ok {
+		result.Country = country
+	}
+
+	return result, nil
+}

internal/publicip/ipinfo/model.go

@@ -0,0 +1,22 @@
+package ipinfo
+
+import "net"
+
+type Response struct {
+	IP       net.IP `json:"ip,omitempty"`
+	Region   string `json:"region,omitempty"`
+	Country  string `json:"country,omitempty"`
+	City     string `json:"city,omitempty"`
+	Hostname string `json:"hostname,omitempty"`
+	Loc      string `json:"loc,omitempty"`
+	Org      string `json:"org,omitempty"`
+	Postal   string `json:"postal,omitempty"`
+	Timezone string `json:"timezone,omitempty"`
+}
+
+func (r Response) Copy() (copied Response) {
+	copied = r
+	copied.IP = make(net.IP, len(r.IP))
+	copy(copied.IP, r.IP)
+	return copied
+}

internal/publicip/ipinfo/multi.go

@@ -0,0 +1,54 @@
+package ipinfo
+
+import (
+	"context"
+	"net"
+)
+
+// FetchMultiInfo obtains the public IP address information for every IP
+// addresses provided and returns a slice of results with the corresponding
+// order as to the IP addresses slice order.
+// If an error is encountered, all the operations are canceled and
+// an error is returned, so the results returned should be considered
+// incomplete in this case.
+func (f *Fetch) FetchMultiInfo(ctx context.Context, ips []net.IP) (
+	results []Response, err error) {
+	ctx, cancel := context.WithCancel(ctx)
+
+	type asyncResult struct {
+		index  int
+		result Response
+		err    error
+	}
+	resultsCh := make(chan asyncResult)
+
+	for i, ip := range ips {
+		go func(index int, ip net.IP) {
+			aResult := asyncResult{
+				index: index,
+			}
+			aResult.result, aResult.err = f.FetchInfo(ctx, ip)
+			resultsCh <- aResult
+		}(i, ip)
+	}
+
+	results = make([]Response, len(ips))
+	for i := 0; i < len(ips); i++ {
+		aResult := <-resultsCh
+		if aResult.err != nil {
+			if err == nil {
+				// Cancel on the first error encountered
+				err = aResult.err
+				cancel()
+			}
+			continue // ignore errors after the first one
+		}
+
+		results[aResult.index] = aResult.result
+	}
+
+	close(resultsCh)
+	cancel()
+
+	return results, err
+}