Obtain PIA v4 server information from API (#257)

- Obtain CN for port forwarding https verification
- Obtain for each server if they support port forwarding
- Obtain for each server their IP address for openvpn UDP and openvpn TCP (one for each)
- Updater program updated to use API
- Hardcoded values updated for PIA v3 and v4 servers
- Clearer separation between pia v3 and v4
- Fixes #250

internal/updater/pia.go

@@ -1,146 +0,0 @@
-package updater
-
-import (
-	"context"
-	"fmt"
-	"net"
-	"sort"
-	"strings"
-	"sync"
-
-	"github.com/qdm12/gluetun/internal/models"
-)
-
-func (u *updater) updatePIA() (err error) {
-	const zipURL = "https://www.privateinternetaccess.com/openvpn/openvpn-ip-nextgen.zip"
-	contents, err := fetchAndExtractFiles(zipURL)
-	if err != nil {
-		return err
-	}
-	servers := make([]models.PIAServer, 0, len(contents))
-	for fileName, content := range contents {
-		remoteLines := extractRemoteLinesFromOpenvpn(content)
-		if len(remoteLines) == 0 {
-			return fmt.Errorf("cannot find any remote lines in %s", fileName)
-		}
-		IPs := extractIPsFromRemoteLines(remoteLines)
-		if len(IPs) == 0 {
-			return fmt.Errorf("cannot find any IP addresses in %s", fileName)
-		}
-		region := strings.TrimSuffix(fileName, ".ovpn")
-		server := models.PIAServer{
-			Region: region,
-			IPs:    uniqueSortedIPs(IPs),
-		}
-		servers = append(servers, server)
-	}
-	sort.Slice(servers, func(i, j int) bool {
-		return servers[i].Region < servers[j].Region
-	})
-	if u.options.Stdout {
-		u.println(stringifyPIAServers(servers))
-	}
-	u.servers.Pia.Timestamp = u.timeNow().Unix()
-	u.servers.Pia.Servers = servers
-	return nil
-}
-
-func (u *updater) updatePIAOld(ctx context.Context) (err error) {
-	const zipURL = "https://www.privateinternetaccess.com/openvpn/openvpn.zip"
-	contents, err := fetchAndExtractFiles(zipURL)
-	if err != nil {
-		return err
-	}
-	const maxGoroutines = 10
-	guard := make(chan struct{}, maxGoroutines)
-	errors := make(chan error)
-	serversCh := make(chan models.PIAServer)
-	servers := make([]models.PIAServer, 0, len(contents))
-	ctx, cancel := context.WithCancel(ctx)
-	wg := &sync.WaitGroup{}
-	defer func() {
-		cancel()
-		wg.Wait()
-		defer close(guard)
-		defer close(errors)
-		defer close(serversCh)
-	}()
-	for fileName, content := range contents {
-		remoteLines := extractRemoteLinesFromOpenvpn(content)
-		if len(remoteLines) == 0 {
-			return fmt.Errorf("cannot find any remote lines in %s", fileName)
-		}
-		hosts := extractHostnamesFromRemoteLines(remoteLines)
-		if len(hosts) == 0 {
-			return fmt.Errorf("cannot find any hosts in %s", fileName)
-		}
-		region := strings.TrimSuffix(fileName, ".ovpn")
-		wg.Add(1)
-		go resolvePIAHostname(ctx, wg, region, hosts, u.lookupIP, errors, serversCh, guard)
-	}
-	for range contents {
-		select {
-		case err := <-errors:
-			return err
-		case server := <-serversCh:
-			servers = append(servers, server)
-		}
-	}
-	sort.Slice(servers, func(i, j int) bool {
-		return servers[i].Region < servers[j].Region
-	})
-	if u.options.Stdout {
-		u.println(stringifyPIAOldServers(servers))
-	}
-	u.servers.PiaOld.Timestamp = u.timeNow().Unix()
-	u.servers.PiaOld.Servers = servers
-	return nil
-}
-
-func resolvePIAHostname(ctx context.Context, wg *sync.WaitGroup,
-	region string, hosts []string, lookupIP lookupIPFunc,
-	errors chan<- error, serversCh chan<- models.PIAServer, guard chan struct{}) {
-	guard <- struct{}{}
-	defer func() {
-		<-guard
-		wg.Done()
-	}()
-	var IPs []net.IP //nolint:prealloc
-	// usually one single host in this case
-	// so no need to run in goroutines the for loop below
-	for _, host := range hosts {
-		const repetition = 5
-		newIPs, err := resolveRepeat(ctx, lookupIP, host, repetition)
-		if err != nil {
-			errors <- err
-			return
-		}
-		IPs = append(IPs, newIPs...)
-	}
-	serversCh <- models.PIAServer{
-		Region: region,
-		IPs:    uniqueSortedIPs(IPs),
-	}
-}
-
-func stringifyPIAServers(servers []models.PIAServer) (s string) {
-	s = "func PIAServers() []models.PIAServer {\n"
-	s += "	return []models.PIAServer{\n"
-	for _, server := range servers {
-		s += "		" + server.String() + ",\n"
-	}
-	s += "	}\n"
-	s += "}"
-	return s
-}
-
-func stringifyPIAOldServers(servers []models.PIAServer) (s string) {
-	s = "func PIAOldServers() []models.PIAServer {\n"
-	s += "	return []models.PIAServer{\n"
-	for _, server := range servers {
-		s += "		" + server.String() + ",\n"
-	}
-	s += "	}\n"
-	s += "}"
-	return s
-}