Deprecate IPWhiteList middleware in favor of IPAllowList

Co-authored-by: Kevin Pollet <pollet.kevin@gmail.com>

pkg/middlewares/ipallowlist/ip_allowlist.go

@@ -0,0 +1,88 @@
+package ipallowlist
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+
+	"github.com/opentracing/opentracing-go/ext"
+	"github.com/traefik/traefik/v2/pkg/config/dynamic"
+	"github.com/traefik/traefik/v2/pkg/ip"
+	"github.com/traefik/traefik/v2/pkg/log"
+	"github.com/traefik/traefik/v2/pkg/middlewares"
+	"github.com/traefik/traefik/v2/pkg/tracing"
+)
+
+const (
+	typeName = "IPAllowLister"
+)
+
+// ipAllowLister is a middleware that provides Checks of the Requesting IP against a set of Allowlists.
+type ipAllowLister struct {
+	next        http.Handler
+	allowLister *ip.Checker
+	strategy    ip.Strategy
+	name        string
+}
+
+// New builds a new IPAllowLister given a list of CIDR-Strings to allow.
+func New(ctx context.Context, next http.Handler, config dynamic.IPAllowList, name string) (http.Handler, error) {
+	logger := log.FromContext(middlewares.GetLoggerCtx(ctx, name, typeName))
+	logger.Debug("Creating middleware")
+
+	if len(config.SourceRange) == 0 {
+		return nil, errors.New("sourceRange is empty, IPAllowLister not created")
+	}
+
+	checker, err := ip.NewChecker(config.SourceRange)
+	if err != nil {
+		return nil, fmt.Errorf("cannot parse CIDRs %s: %w", config.SourceRange, err)
+	}
+
+	strategy, err := config.IPStrategy.Get()
+	if err != nil {
+		return nil, err
+	}
+
+	logger.Debugf("Setting up IPAllowLister with sourceRange: %s", config.SourceRange)
+
+	return &ipAllowLister{
+		strategy:    strategy,
+		allowLister: checker,
+		next:        next,
+		name:        name,
+	}, nil
+}
+
+func (al *ipAllowLister) GetTracingInformation() (string, ext.SpanKindEnum) {
+	return al.name, tracing.SpanKindNoneEnum
+}
+
+func (al *ipAllowLister) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
+	ctx := middlewares.GetLoggerCtx(req.Context(), al.name, typeName)
+	logger := log.FromContext(ctx)
+
+	clientIP := al.strategy.GetIP(req)
+	err := al.allowLister.IsAuthorized(clientIP)
+	if err != nil {
+		msg := fmt.Sprintf("Rejecting IP %s: %v", clientIP, err)
+		logger.Debug(msg)
+		tracing.SetErrorWithEvent(req, msg)
+		reject(ctx, rw)
+		return
+	}
+	logger.Debugf("Accepting IP %s", clientIP)
+
+	al.next.ServeHTTP(rw, req)
+}
+
+func reject(ctx context.Context, rw http.ResponseWriter) {
+	statusCode := http.StatusForbidden
+
+	rw.WriteHeader(statusCode)
+	_, err := rw.Write([]byte(http.StatusText(statusCode)))
+	if err != nil {
+		log.FromContext(ctx).Error(err)
+	}
+}