build: move e2e dependencies into e2e/go.mod

Several packages are only used while running the e2e suite. These
packages are less important to update, as the they can not influence the
final executable that is part of the Ceph-CSI container-image.

By moving these dependencies out of the main Ceph-CSI go.mod, it is
easier to identify if a reported CVE affects Ceph-CSI, or only the
testing (like most of the Kubernetes CVEs).

Signed-off-by: Niels de Vos <ndevos@ibm.com>

e2e/vendor/go.etcd.io/etcd/client/v3/internal/endpoint/endpoint.go

@@ -0,0 +1,134 @@
+// Copyright 2021 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package endpoint
+
+import (
+	"fmt"
+	"net"
+	"net/url"
+	"path"
+	"strings"
+)
+
+type CredsRequirement int
+
+const (
+	// CREDS_REQUIRE - Credentials/certificate required for thi type of connection.
+	CREDS_REQUIRE CredsRequirement = iota
+	// CREDS_DROP - Credentials/certificate not needed and should get ignored.
+	CREDS_DROP
+	// CREDS_OPTIONAL - Credentials/certificate might be used if supplied
+	CREDS_OPTIONAL
+)
+
+func extractHostFromHostPort(ep string) string {
+	host, _, err := net.SplitHostPort(ep)
+	if err != nil {
+		return ep
+	}
+	return host
+}
+
+// mustSplit2 returns the values from strings.SplitN(s, sep, 2).
+// If sep is not found, it returns ("", "", false) instead.
+func mustSplit2(s, sep string) (string, string) {
+	spl := strings.SplitN(s, sep, 2)
+	if len(spl) < 2 {
+		panic(fmt.Errorf("token '%v' expected to have separator sep: `%v`", s, sep))
+	}
+	return spl[0], spl[1]
+}
+
+func schemeToCredsRequirement(schema string) CredsRequirement {
+	switch schema {
+	case "https", "unixs":
+		return CREDS_REQUIRE
+	case "http":
+		return CREDS_DROP
+	case "unix":
+		// Preserving previous behavior from:
+		// https://github.com/etcd-io/etcd/blob/dae29bb719dd69dc119146fc297a0628fcc1ccf8/client/v3/client.go#L212
+		// that likely was a bug due to missing 'fallthrough'.
+		// At the same time it seems legit to let the users decide whether they
+		// want credential control or not (and 'unixs' schema is not a standard thing).
+		return CREDS_OPTIONAL
+	case "":
+		return CREDS_OPTIONAL
+	default:
+		return CREDS_OPTIONAL
+	}
+}
+
+// This function translates endpoints names supported by etcd server into
+// endpoints as supported by grpc with additional information
+// (server_name for cert validation, requireCreds - whether certs are needed).
+// The main differences:
+//   - etcd supports unixs & https names as opposed to unix & http to
+//     distinguish need to configure certificates.
+//   - etcd support http(s) names as opposed to tcp supported by grpc/dial method.
+//   - etcd supports unix(s)://local-file naming schema
+//     (as opposed to unix:local-file canonical name used by grpc for current dir files).
+//   - Within the unix(s) schemas, the last segment (filename) without 'port' (content after colon)
+//     is considered serverName - to allow local testing of cert-protected communication.
+//
+// See more:
+//   - https://github.com/grpc/grpc-go/blob/26c143bd5f59344a4b8a1e491e0f5e18aa97abc7/internal/grpcutil/target.go#L47
+//   - https://golang.org/pkg/net/#Dial
+//   - https://github.com/grpc/grpc/blob/master/doc/naming.md
+func translateEndpoint(ep string) (addr string, serverName string, requireCreds CredsRequirement) {
+	if strings.HasPrefix(ep, "unix:") || strings.HasPrefix(ep, "unixs:") {
+		if strings.HasPrefix(ep, "unix:///") || strings.HasPrefix(ep, "unixs:///") {
+			// absolute path case
+			schema, absolutePath := mustSplit2(ep, "://")
+			return "unix://" + absolutePath, path.Base(absolutePath), schemeToCredsRequirement(schema)
+		}
+		if strings.HasPrefix(ep, "unix://") || strings.HasPrefix(ep, "unixs://") {
+			// legacy etcd local path
+			schema, localPath := mustSplit2(ep, "://")
+			return "unix:" + localPath, path.Base(localPath), schemeToCredsRequirement(schema)
+		}
+		schema, localPath := mustSplit2(ep, ":")
+		return "unix:" + localPath, path.Base(localPath), schemeToCredsRequirement(schema)
+	}
+
+	if strings.Contains(ep, "://") {
+		url, err := url.Parse(ep)
+		if err != nil {
+			return ep, ep, CREDS_OPTIONAL
+		}
+		if url.Scheme == "http" || url.Scheme == "https" {
+			return url.Host, url.Host, schemeToCredsRequirement(url.Scheme)
+		}
+		return ep, url.Host, schemeToCredsRequirement(url.Scheme)
+	}
+	// Handles plain addresses like 10.0.0.44:437.
+	return ep, ep, CREDS_OPTIONAL
+}
+
+// RequiresCredentials returns whether given endpoint requires
+// credentials/certificates for connection.
+func RequiresCredentials(ep string) CredsRequirement {
+	_, _, requireCreds := translateEndpoint(ep)
+	return requireCreds
+}
+
+// Interpret endpoint parses an endpoint of the form
+// (http|https)://<host>*|(unix|unixs)://<path>)
+// and returns low-level address (supported by 'net') to connect to,
+// and a server name used for x509 certificate matching.
+func Interpret(ep string) (address string, serverName string) {
+	addr, serverName, _ := translateEndpoint(ep)
+	return addr, serverName
+}

e2e/vendor/go.etcd.io/etcd/client/v3/internal/resolver/resolver.go

@@ -0,0 +1,74 @@
+// Copyright 2021 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package resolver
+
+import (
+	"go.etcd.io/etcd/client/v3/internal/endpoint"
+	"google.golang.org/grpc/resolver"
+	"google.golang.org/grpc/resolver/manual"
+	"google.golang.org/grpc/serviceconfig"
+)
+
+const (
+	Schema = "etcd-endpoints"
+)
+
+// EtcdManualResolver is a Resolver (and resolver.Builder) that can be updated
+// using SetEndpoints.
+type EtcdManualResolver struct {
+	*manual.Resolver
+	endpoints     []string
+	serviceConfig *serviceconfig.ParseResult
+}
+
+func New(endpoints ...string) *EtcdManualResolver {
+	r := manual.NewBuilderWithScheme(Schema)
+	return &EtcdManualResolver{Resolver: r, endpoints: endpoints, serviceConfig: nil}
+}
+
+// Build returns itself for Resolver, because it's both a builder and a resolver.
+func (r *EtcdManualResolver) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) {
+	r.serviceConfig = cc.ParseServiceConfig(`{"loadBalancingPolicy": "round_robin"}`)
+	if r.serviceConfig.Err != nil {
+		return nil, r.serviceConfig.Err
+	}
+	res, err := r.Resolver.Build(target, cc, opts)
+	if err != nil {
+		return nil, err
+	}
+	// Populates endpoints stored in r into ClientConn (cc).
+	r.updateState()
+	return res, nil
+}
+
+func (r *EtcdManualResolver) SetEndpoints(endpoints []string) {
+	r.endpoints = endpoints
+	r.updateState()
+}
+
+func (r EtcdManualResolver) updateState() {
+	if r.CC != nil {
+		addresses := make([]resolver.Address, len(r.endpoints))
+		for i, ep := range r.endpoints {
+			addr, serverName := endpoint.Interpret(ep)
+			addresses[i] = resolver.Address{Addr: addr, ServerName: serverName}
+		}
+		state := resolver.State{
+			Addresses:     addresses,
+			ServiceConfig: r.serviceConfig,
+		}
+		r.UpdateState(state)
+	}
+}