8d512852a4
- Use loopstate package - Loop interface composition - Return concrete struct from constructors - Split into more files - Add publicip/state package
73 lines
1.5 KiB
Go
73 lines
1.5 KiB
Go
// Package publicip defines interfaces to get your public IP address.
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package publicip
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import (
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"context"
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"errors"
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"fmt"
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"io"
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"math/rand"
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"net"
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"net/http"
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"strings"
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)
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type Fetcher interface {
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FetchPublicIP(ctx context.Context) (ip net.IP, err error)
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}
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type Fetch struct {
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client *http.Client
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randIntn func(n int) int
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}
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func NewFetch(client *http.Client) *Fetch {
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return &Fetch{
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client: client,
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randIntn: rand.Intn,
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}
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}
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var ErrParseIP = errors.New("cannot parse IP address")
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func (f *Fetch) FetchPublicIP(ctx context.Context) (ip net.IP, err error) {
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urls := []string{
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"https://ifconfig.me/ip",
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"http://ip1.dynupdate.no-ip.com:8245",
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"http://ip1.dynupdate.no-ip.com",
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"https://api.ipify.org",
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"https://diagnostic.opendns.com/myip",
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"https://domains.google.com/checkip",
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"https://ifconfig.io/ip",
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"https://ipinfo.io/ip",
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}
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url := urls[f.randIntn(len(urls))]
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req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
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if err != nil {
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return nil, err
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}
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response, err := f.client.Do(req)
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if err != nil {
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return nil, err
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}
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defer response.Body.Close()
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if response.StatusCode != http.StatusOK {
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return nil, fmt.Errorf("%w from %s: %s", ErrBadStatusCode, url, response.Status)
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}
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content, err := io.ReadAll(response.Body)
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if err != nil {
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return nil, fmt.Errorf("%w: %s", ErrCannotReadBody, err)
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}
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s := strings.ReplaceAll(string(content), "\n", "")
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ip = net.ParseIP(s)
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if ip == nil {
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return nil, fmt.Errorf("%w: %s", ErrParseIP, s)
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}
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return ip, nil
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}
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