feat: add VPNsecure.me support (#848)

- `OPENVPN_ENCRYPTED_KEY` environment variable 
- `OPENVPN_ENCRYPTED_KEY_SECRETFILE` environment variable 
- `OPENVPN_KEY_PASSPHRASE` environment variable 
- `OPENVPN_KEY_PASSPHRASE_SECRETFILE` environment variable 
- `PREMIUM_ONLY` environment variable
- OpenVPN user and password not required for vpnsecure provider

internal/provider/vpnsecure/updater/website.go

@@ -0,0 +1,239 @@
+package updater
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/common"
+	htmlutils "github.com/qdm12/gluetun/internal/updater/html"
+	"golang.org/x/net/html"
+)
+
+func fetchServers(ctx context.Context, client *http.Client,
+	warner common.Warner) (servers []models.Server, err error) {
+	const url = "https://www.vpnsecure.me/vpn-locations/"
+	rootNode, err := htmlutils.Fetch(ctx, client, url)
+	if err != nil {
+		return nil, fmt.Errorf("fetching HTML code: %w", err)
+	}
+
+	servers, warnings, err := parseHTML(rootNode)
+	for _, warning := range warnings {
+		warner.Warn(warning)
+	}
+	if err != nil {
+		return nil, fmt.Errorf("parsing HTML code: %w", err)
+	}
+
+	return servers, nil
+}
+
+var (
+	ErrHTMLServersDivNotFound = errors.New("HTML servers container div not found")
+)
+
+const divString = "div"
+
+func parseHTML(rootNode *html.Node) (servers []models.Server,
+	warnings []string, err error) {
+	// Find div container for all servers, searching with BFS.
+	serversDiv := findServersDiv(rootNode)
+	if serversDiv == nil {
+		return nil, nil, htmlutils.WrapError(ErrHTMLServersDivNotFound, rootNode)
+	}
+
+	for countryNode := serversDiv.FirstChild; countryNode != nil; countryNode = countryNode.NextSibling {
+		if countryNode.Data != divString {
+			// empty line(s) and tab(s)
+			continue
+		}
+
+		country := findCountry(countryNode)
+		if country == "" {
+			warnings = append(warnings, htmlutils.WrapWarning("country not found", countryNode))
+			continue
+		}
+
+		grid := htmlutils.BFS(countryNode, matchGridDiv)
+		if grid == nil {
+			warnings = append(warnings, htmlutils.WrapWarning("grid div not found", countryNode))
+			continue
+		}
+
+		gridItems := htmlutils.DirectChildren(grid, matchGridItem)
+		if len(gridItems) == 0 {
+			warnings = append(warnings, htmlutils.WrapWarning("no grid item found", grid))
+			continue
+		}
+
+		for _, gridItem := range gridItems {
+			server, warning := parseHTMLGridItem(gridItem)
+			if warning != "" {
+				warnings = append(warnings, warning)
+				continue
+			}
+
+			server.Country = country
+			servers = append(servers, server)
+		}
+	}
+
+	return servers, warnings, nil
+}
+
+func parseHTMLGridItem(gridItem *html.Node) (
+	server models.Server, warning string) {
+	gridItemDT := htmlutils.DirectChild(gridItem, matchDT)
+	if gridItemDT == nil {
+		return server, htmlutils.WrapWarning("grid item <dt> not found", gridItem)
+	}
+
+	host := findHost(gridItemDT)
+	if host == "" {
+		return server, htmlutils.WrapWarning("host not found", gridItemDT)
+	}
+
+	status := findStatus(gridItemDT)
+	if !strings.EqualFold(status, "up") {
+		warning := fmt.Sprintf("skipping server with host %s which has status %q", host, status)
+		warning = htmlutils.WrapWarning(warning, gridItemDT)
+		return server, warning
+	}
+
+	gridItemDD := htmlutils.DirectChild(gridItem, matchDD)
+	if gridItemDD == nil {
+		return server, htmlutils.WrapWarning("grid item dd not found", gridItem)
+	}
+
+	region := findSpanStrong(gridItemDD, "Region:")
+	if region == "" {
+		warning := fmt.Sprintf("region for host %s not found", host)
+		return server, htmlutils.WrapWarning(warning, gridItemDD)
+	}
+
+	city := findSpanStrong(gridItemDD, "City:")
+	if city == "" {
+		warning := fmt.Sprintf("region for host %s not found", host)
+		return server, htmlutils.WrapWarning(warning, gridItemDD)
+	}
+
+	premiumString := findSpanStrong(gridItemDD, "Premium:")
+	if premiumString == "" {
+		warning := fmt.Sprintf("premium for host %s not found", host)
+		return server, htmlutils.WrapWarning(warning, gridItemDD)
+	}
+
+	return models.Server{
+		Region:   region,
+		City:     city,
+		Hostname: host + ".isponeder.com",
+		Premium:  strings.EqualFold(premiumString, "yes"),
+	}, ""
+}
+
+func findCountry(countryNode *html.Node) (country string) {
+	for node := countryNode.FirstChild; node != nil; node = node.NextSibling {
+		if node.Data != "a" {
+			continue
+		}
+		for subNode := node.FirstChild; subNode != nil; subNode = subNode.NextSibling {
+			if subNode.Data != "h4" {
+				continue
+			}
+			return subNode.FirstChild.Data
+		}
+	}
+	return ""
+}
+
+func findServersDiv(rootNode *html.Node) (serversDiv *html.Node) {
+	locationsDiv := htmlutils.BFS(rootNode, matchLocationsListDiv)
+	if locationsDiv == nil {
+		return nil
+	}
+
+	return htmlutils.BFS(locationsDiv, matchServersDiv)
+}
+
+func findHost(gridItemDT *html.Node) (host string) {
+	hostNode := htmlutils.DirectChild(gridItemDT, matchText)
+	return strings.TrimSpace(hostNode.Data)
+}
+
+func matchText(node *html.Node) (match bool) {
+	if node.Type != html.TextNode {
+		return false
+	}
+	data := strings.TrimSpace(node.Data)
+	return data != ""
+}
+
+func findStatus(gridItemDT *html.Node) (status string) {
+	statusNode := htmlutils.DirectChild(gridItemDT, matchStatusSpan)
+	return strings.TrimSpace(statusNode.FirstChild.Data)
+}
+
+func matchServersDiv(node *html.Node) (match bool) {
+	return node != nil && node.Data == divString &&
+		htmlutils.HasClassStrings(node, "blk__i")
+}
+
+func matchLocationsListDiv(node *html.Node) (match bool) {
+	return node != nil && node.Data == divString &&
+		htmlutils.HasClassStrings(node, "locations-list")
+}
+
+func matchGridDiv(node *html.Node) (match bool) {
+	return node != nil && node.Data == divString &&
+		htmlutils.HasClassStrings(node, "grid--locations")
+}
+
+func matchGridItem(node *html.Node) (match bool) {
+	return node != nil && node.Data == "dl" &&
+		htmlutils.HasClassStrings(node, "grid__i")
+}
+
+func matchDT(node *html.Node) (match bool) {
+	return node != nil && node.Data == "dt"
+}
+
+func matchDD(node *html.Node) (match bool) {
+	return node != nil && node.Data == "dd"
+}
+
+func matchStatusSpan(node *html.Node) (match bool) {
+	return node.Data == "span" && htmlutils.HasClassStrings(node, "status")
+}
+
+func findSpanStrong(gridItemDD *html.Node, spanData string) (
+	strongValue string) {
+	spanFound := false
+	for child := gridItemDD.FirstChild; child != nil; child = child.NextSibling {
+		if !htmlutils.MatchData("div")(child) {
+			continue
+		}
+
+		for subchild := child.FirstChild; subchild != nil; subchild = subchild.NextSibling {
+			if htmlutils.MatchData("span")(subchild) && subchild.FirstChild.Data == spanData {
+				spanFound = true
+				break
+			}
+		}
+
+		if !spanFound {
+			continue
+		}
+
+		for subchild := child.FirstChild; subchild != nil; subchild = subchild.NextSibling {
+			if htmlutils.MatchData("strong")(subchild) {
+				return subchild.FirstChild.Data
+			}
+		}
+	}
+
+	return ""
+}